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2026,46(2):14-22
, DOI: 10.13961/j.cnki.stbctb.2026.02.038
Abstract:
[Objective] The key mechanisms by which amorphous iron oxide regulates the mechanical properties of Benggang soil were analyzed from a microscopic perspective in order to provide a theoretical basis for the prevention and control of Benggang erosion. [Methods] Kaolinite, the dominant clay mineral in soil from a typical Benggang area of Fujian Province, was selected as the research object. By incorporating amorphous iron oxide at different concentrations(1, 2, 3, and 10 g/kg) into kaolinite and utilizing X-ray diffraction(XRD), scanning electron microscopy(SEM), and direct shear tests, this study analyzed its regulatory effects on soil microstructure and shear strength parameters. [Results] XRD analysis revealed that amorphous iron oxide did not undergo a chemical reaction with kaolinite but primarily altered mineral characteristics through physical coating. The concentration of amorphous iron oxide significantly influenced the distribution of cemented aggregates across different particle sizes, demonstrating a pronounced regulatory role in the formation of aggregates within the 2—250 μm range. Among microstructural parameters, only particle long-axis and roundness exhibited significant changes. The long-axis decreased by 22% in samples with the 3 g/kg treatment, while roundness was reduced by 25% in samples with the 2 g/kg treatment. The coefficients of variation for all other parameters remained below 15%. The treatment with 3 g/kg consistently exhibited the highest shear strength across all confining pressure levels. The enhancement in shear strength was closely associated with the observed microstructural alterations. Further analysis indicated that the 3 g/kg treatment resulted in the most substantial improvement in cohesion, which increased by 24.82% compared to pure kaolinite. In contrast, the internal friction angle varied by less than 5.30%. [Conclusion] Amorphous iron oxide enhances soil shear strength by optimizing soil structure through cementation and encapsulation.
[Objective] The key mechanisms by which amorphous iron oxide regulates the mechanical properties of Benggang soil were analyzed from a microscopic perspective in order to provide a theoretical basis for the prevention and control of Benggang erosion. [Methods] Kaolinite, the dominant clay mineral in soil from a typical Benggang area of Fujian Province, was selected as the research object. By incorporating amorphous iron oxide at different concentrations(1, 2, 3, and 10 g/kg) into kaolinite and utilizing X-ray diffraction(XRD), scanning electron microscopy(SEM), and direct shear tests, this study analyzed its regulatory effects on soil microstructure and shear strength parameters. [Results] XRD analysis revealed that amorphous iron oxide did not undergo a chemical reaction with kaolinite but primarily altered mineral characteristics through physical coating. The concentration of amorphous iron oxide significantly influenced the distribution of cemented aggregates across different particle sizes, demonstrating a pronounced regulatory role in the formation of aggregates within the 2—250 μm range. Among microstructural parameters, only particle long-axis and roundness exhibited significant changes. The long-axis decreased by 22% in samples with the 3 g/kg treatment, while roundness was reduced by 25% in samples with the 2 g/kg treatment. The coefficients of variation for all other parameters remained below 15%. The treatment with 3 g/kg consistently exhibited the highest shear strength across all confining pressure levels. The enhancement in shear strength was closely associated with the observed microstructural alterations. Further analysis indicated that the 3 g/kg treatment resulted in the most substantial improvement in cohesion, which increased by 24.82% compared to pure kaolinite. In contrast, the internal friction angle varied by less than 5.30%. [Conclusion] Amorphous iron oxide enhances soil shear strength by optimizing soil structure through cementation and encapsulation.
2026,46(2):23-31,52
, DOI: 10.13961/j.cnki.stbctb.2026.02.030
Abstract:
[Objective] The water-holding characteristics and strength characteristics of unsaturated lime-stabilized loess cushion layers were investigated, and the influence of different lime contents on its matric suction and strength was revealed, in order to provide guidance and reference for the construction and theoretical research of loess building foundations and subgrades. [Methods] Laboratory soil-water characteristic tests and unsaturated triaxial tests were conducted to study the soil-water characteristics, unsaturated strength, and softening constitutive model of lime-stabilized unsaturated loess. Four lime contents(0, 3%, 6%, and 9%) were set to reveal the influence of lime content on matric suction. The matric suction was set at 0, 50, 100 kPa, and 200 kPa, respectively, to explore its influence on strength. [Results] ① Matric suction increased with increasing lime content.② A soil-water characteristic model considering the influence of lime content was proposed, and this model could accurately describe the soil-water characteristics of lime-stabilized loess. A nonlinear model capable of describing the softening behavior of lime-stabilized loess was established by introducing a damage variable.③ The cohesion and internal friction angle of the stabilized soil increased as the lime content increased. When the lime content was 9%, with the increase of matric suction, the cohesion of the lime-stabilized loess gradually increased, while the change in the internal friction angle was very small. [Conclusion] The lime content on the soil-water characteristics of stabilized loess has a significant influence. Additionally, the nonlinear model can accurately describe the stress-strain curve of lime-stabilized soil, yielding relatively good results.
[Objective] The water-holding characteristics and strength characteristics of unsaturated lime-stabilized loess cushion layers were investigated, and the influence of different lime contents on its matric suction and strength was revealed, in order to provide guidance and reference for the construction and theoretical research of loess building foundations and subgrades. [Methods] Laboratory soil-water characteristic tests and unsaturated triaxial tests were conducted to study the soil-water characteristics, unsaturated strength, and softening constitutive model of lime-stabilized unsaturated loess. Four lime contents(0, 3%, 6%, and 9%) were set to reveal the influence of lime content on matric suction. The matric suction was set at 0, 50, 100 kPa, and 200 kPa, respectively, to explore its influence on strength. [Results] ① Matric suction increased with increasing lime content.② A soil-water characteristic model considering the influence of lime content was proposed, and this model could accurately describe the soil-water characteristics of lime-stabilized loess. A nonlinear model capable of describing the softening behavior of lime-stabilized loess was established by introducing a damage variable.③ The cohesion and internal friction angle of the stabilized soil increased as the lime content increased. When the lime content was 9%, with the increase of matric suction, the cohesion of the lime-stabilized loess gradually increased, while the change in the internal friction angle was very small. [Conclusion] The lime content on the soil-water characteristics of stabilized loess has a significant influence. Additionally, the nonlinear model can accurately describe the stress-strain curve of lime-stabilized soil, yielding relatively good results.
2026,46(2):32-42
, DOI: 10.13961/j.cnki.stbctb.2026.02.001
Abstract:
[Objective] The mechanisms through which seasonal freeze-thaw cycles, coupled with initial water content, attenuate the collapsibility of Ili loess were revealed, and a quantitative relationship between microstructural reconfiguration and macroscopic collapsibility variations was established, in order to provide a theoretical basis for prevention and control of loess landslides in seasonally frozen soil regions. [Methods] Freezethaw cycling tests were performed on samples with different initial water contents and cycle numbers, accompanied by laboratory collapsibility tests and scanning electron microscope(SEM) observations. Image and statistics-based analyses were conducted to quantitatively characterize microscopic parameters such as pore size distribution, directional frequency, pore abundance, and pore fractal dimension. Correlations between these parameters and the collapsibility coefficient were established, forming an integrated macro-micro analytical framework. [Results] ① The collapsibility coefficient decreased significantly with an increase in freeze-thaw cycles for all water contents, and samples with lower water contents were more sensitive. For loess with a water content of 14.2%, the peak collapsibility coefficient decreased from 0.094 to 0.084 after nine cycles, a reduction of approximately 10.6%. For loess with a water content of 20.2%, the peak collapsibility coefficient decreased from 0.079 to 0.076 after nine cycles, a reduction of about 3.8%.② Freeze-thaw cycles weakened interparticle cementation and altered particle connections and arrangement, thereby driving internal structural reorganization toward a new stable state.③ The pore system underwent systematic evolution. The proportion of large pores declined, the pore-size spectrum became finer and more uniform, pore directions were re-arranged, and both pore abundance and pore fractal dimension changed accordingly.④ The microstructural statistical patterns were consistent with qualitative observations and the macroscopic evolution of collapsibility. [Conclusion] Freeze-thaw cycles reduce interparticle bonding and remodel the pore-particle structure. Consequently, the reduction of large pores and changes in fractal dimension constitutes the core mechanisms driving the macroscopic weakening of collapsibility. Based on this, a physical process model of ‘freeze-thaw → microstructural reconfiguration → collapsibility response' is established, providing theoretical support for the monitoring and prevention of loess landslides in seasonally frozen soil regions such as the Ili area.
[Objective] The mechanisms through which seasonal freeze-thaw cycles, coupled with initial water content, attenuate the collapsibility of Ili loess were revealed, and a quantitative relationship between microstructural reconfiguration and macroscopic collapsibility variations was established, in order to provide a theoretical basis for prevention and control of loess landslides in seasonally frozen soil regions. [Methods] Freezethaw cycling tests were performed on samples with different initial water contents and cycle numbers, accompanied by laboratory collapsibility tests and scanning electron microscope(SEM) observations. Image and statistics-based analyses were conducted to quantitatively characterize microscopic parameters such as pore size distribution, directional frequency, pore abundance, and pore fractal dimension. Correlations between these parameters and the collapsibility coefficient were established, forming an integrated macro-micro analytical framework. [Results] ① The collapsibility coefficient decreased significantly with an increase in freeze-thaw cycles for all water contents, and samples with lower water contents were more sensitive. For loess with a water content of 14.2%, the peak collapsibility coefficient decreased from 0.094 to 0.084 after nine cycles, a reduction of approximately 10.6%. For loess with a water content of 20.2%, the peak collapsibility coefficient decreased from 0.079 to 0.076 after nine cycles, a reduction of about 3.8%.② Freeze-thaw cycles weakened interparticle cementation and altered particle connections and arrangement, thereby driving internal structural reorganization toward a new stable state.③ The pore system underwent systematic evolution. The proportion of large pores declined, the pore-size spectrum became finer and more uniform, pore directions were re-arranged, and both pore abundance and pore fractal dimension changed accordingly.④ The microstructural statistical patterns were consistent with qualitative observations and the macroscopic evolution of collapsibility. [Conclusion] Freeze-thaw cycles reduce interparticle bonding and remodel the pore-particle structure. Consequently, the reduction of large pores and changes in fractal dimension constitutes the core mechanisms driving the macroscopic weakening of collapsibility. Based on this, a physical process model of ‘freeze-thaw → microstructural reconfiguration → collapsibility response' is established, providing theoretical support for the monitoring and prevention of loess landslides in seasonally frozen soil regions such as the Ili area.
2026,46(2):43-52
, DOI: 10.13961/j.cnki.stbctb.2026.02.017
Abstract:
[Objective] The amount of wind-blown sand entering gullies and its migration paths and deposition processes within the gully slopes in the coarse sand area in the middle reaches of the Yellow River were analyzed in order to provide a scientific basis for wind and sand prevention and control in the Yellow River basin. [Methods] Taking the Shajiawan small watershed as the study area, sand drift potential（DP） was calculated based on field monitoring and laboratory analysis using sand samplers, and the actual wind erosion potential（DPa） was derived by incorporating the rainfall inhibition effect. The wind-sand deposition amount in the gully was estimated using a function fitting method. Combined with the soil particle size characteristics of the gully slopes, the wind-sand transport paths and sedimentary characteristics were systematically analyzed. [Results] ① The Shajiawan small watershed was characterized by a high wind energy environment. The annual sand drift potential was 441.95 VU, with a directional variability index of 0.42. The direction of the annual synthetic sand drift potential was perpendicular to the main channel, and the annual wind erosion modulus of the channel was-0.40 t/hm2. Sand drift potential and wind-sand deposition were highest in spring, accounting for 53.74% and 40.25% of the annual total, respectively.② The annual actual wind erosion potential（DPa） considering rainfall suppression was 293.04 VU, which was 27% lower than the sand drift potential. The suppression effect was most pronounced when high wind speeds occurred simultaneously with heavy rainfall.③ As the slope position decreased, the sediment composition changed from silt（76.20%） to predominantly fine sand（74.70%）, with the average particle size changing from 5.52 φ to 2.89 φ. The soil particles became significantly coarser, and the movement mode changed from suspension to saltation. [Conclusion] The process of wind-blown sand entering gullies occurs under the combined effects of high wind energy and gully terrain obstruction, with sediments entering the gullies through saltation.
[Objective] The amount of wind-blown sand entering gullies and its migration paths and deposition processes within the gully slopes in the coarse sand area in the middle reaches of the Yellow River were analyzed in order to provide a scientific basis for wind and sand prevention and control in the Yellow River basin. [Methods] Taking the Shajiawan small watershed as the study area, sand drift potential（DP） was calculated based on field monitoring and laboratory analysis using sand samplers, and the actual wind erosion potential（DPa） was derived by incorporating the rainfall inhibition effect. The wind-sand deposition amount in the gully was estimated using a function fitting method. Combined with the soil particle size characteristics of the gully slopes, the wind-sand transport paths and sedimentary characteristics were systematically analyzed. [Results] ① The Shajiawan small watershed was characterized by a high wind energy environment. The annual sand drift potential was 441.95 VU, with a directional variability index of 0.42. The direction of the annual synthetic sand drift potential was perpendicular to the main channel, and the annual wind erosion modulus of the channel was-0.40 t/hm2. Sand drift potential and wind-sand deposition were highest in spring, accounting for 53.74% and 40.25% of the annual total, respectively.② The annual actual wind erosion potential（DPa） considering rainfall suppression was 293.04 VU, which was 27% lower than the sand drift potential. The suppression effect was most pronounced when high wind speeds occurred simultaneously with heavy rainfall.③ As the slope position decreased, the sediment composition changed from silt（76.20%） to predominantly fine sand（74.70%）, with the average particle size changing from 5.52 φ to 2.89 φ. The soil particles became significantly coarser, and the movement mode changed from suspension to saltation. [Conclusion] The process of wind-blown sand entering gullies occurs under the combined effects of high wind energy and gully terrain obstruction, with sediments entering the gullies through saltation.
2026,46(2):53-64
, DOI: 10.13961/j.cnki.stbctb.2026.02.015
Abstract:
[Objective] The macroscopic and microscopic mechanisms of loess strength degradation under the coupled effects of wet-dry cycles and soluble salt content were analyzed in order to provide a basis for engineering construction and geologic disaster prevention and control in the Ili region. [Methods] The typical loess from the Ili region was taken as the research object. The influence of different numbers of wet-dry cycles and different soluble salt contents on the mechanical properties and microstructure of loess was analyzed through triaxial shear tests, scanning electron microscope(SEM) tests, and nuclear magnetic resonance(NMR) tests. [Results] ① The cohesion decreased by approximately 17.5% after only 10 wet-dry cycles(η=0%). When the soluble salt content increased from 0% to 2%(N=0), cohesion decreased by about 3.5%. However, under their coupled effects(N=10, η =2%), cohesion decreased by 24.3%, demonstrating a significant synergistic deterioration effect.② Soluble salts exerted a highly significant influence on both cohesion and internal friction angle, while wet-dry cycles had a highly significant influence on cohesion and a significant influence on internal friction angle.③ Under low confining pressures, the failure mode of loess shifted from brittle to plastic failure. Under high confining pressures, although the strength remained relatively high, degradation continued.④ With increasing numbers of wet-dry cycles and soluble salt content, fracture development occurred, gradually increasing the pore fractal dimension and pore area ratio of loess. A reduction in micropores, along with a sharp expansion of mesopores and macropores, leading to increased porosity and enhanced connectivity within the pore system. [Conclusion] Under the coupled conditions of wet-dry cycles and soluble salts, the synergistic effects of repeated swelling and shrinkage driven by the wet-dry cycles and crystallization stresses generated by salt dissolution and recrystallization jointly disrupt soil structure. This process leads to strength degradation and structural degradation in Ili loess.
[Objective] The macroscopic and microscopic mechanisms of loess strength degradation under the coupled effects of wet-dry cycles and soluble salt content were analyzed in order to provide a basis for engineering construction and geologic disaster prevention and control in the Ili region. [Methods] The typical loess from the Ili region was taken as the research object. The influence of different numbers of wet-dry cycles and different soluble salt contents on the mechanical properties and microstructure of loess was analyzed through triaxial shear tests, scanning electron microscope(SEM) tests, and nuclear magnetic resonance(NMR) tests. [Results] ① The cohesion decreased by approximately 17.5% after only 10 wet-dry cycles(η=0%). When the soluble salt content increased from 0% to 2%(N=0), cohesion decreased by about 3.5%. However, under their coupled effects(N=10, η =2%), cohesion decreased by 24.3%, demonstrating a significant synergistic deterioration effect.② Soluble salts exerted a highly significant influence on both cohesion and internal friction angle, while wet-dry cycles had a highly significant influence on cohesion and a significant influence on internal friction angle.③ Under low confining pressures, the failure mode of loess shifted from brittle to plastic failure. Under high confining pressures, although the strength remained relatively high, degradation continued.④ With increasing numbers of wet-dry cycles and soluble salt content, fracture development occurred, gradually increasing the pore fractal dimension and pore area ratio of loess. A reduction in micropores, along with a sharp expansion of mesopores and macropores, leading to increased porosity and enhanced connectivity within the pore system. [Conclusion] Under the coupled conditions of wet-dry cycles and soluble salts, the synergistic effects of repeated swelling and shrinkage driven by the wet-dry cycles and crystallization stresses generated by salt dissolution and recrystallization jointly disrupt soil structure. This process leads to strength degradation and structural degradation in Ili loess.
2026,46(2):65-75
, DOI: 10.13961/j.cnki.stbctb.2026.02.007
Abstract:
[Objective] The patterns of soil erosion on slopes in the Xin’an River basin were evaluated in order to provide scientific support for regional soil erosion control and sustainable ecological development. [Methods] Through artificial rainfall simulation experiments,the runoff and sediment yield processes,and their differential erosion characteristics were systematically analyzed under different combinations of rainfall intensity and slope gradient for yellow soil and red soil in the river basin,and a quantitative relationship model between hydrodynamic parameters and sediment yield intensity was established. [Results] ① The runoff rate and sediment yield rate on the slopes of both yellow soil and red soil exhibited a steep initial increase during rainfall onset,followed by gradual stabilization,with both increasing with higher rainfall intensity and slope gradient.Red soil slopes demonstrated higher runoff and sediment yield capacity than yellow soil slopes,particularly under a rainfall intensity of 60 mm/h.② Rainfall intensity and slope gradient synergistically exacerbated runoff and sediment erosion,with rainfall intensity dominating the runoff and sediment transport processes on red soil slopes.When the slope gradient reached 15°and rainfall intensity increased to 60 mm/h,the contribution of slope to sediment loss on yellow soil slopes increased to 59.06%.③ A high correlation was observed between runoff and sediment yield on both soil types.Yellow soil slopes generally exhibited a nonlinear relationship characterized by Y=a/[1+exp-b（X-c）].In contrast,due to rapid saturation caused by poor structure,red soil slopes showed synchronous linear growth between sediment yield and runoff yield under a rainfall intensity of 60 mm/h,described by the function Y=a+bX.④ Among the slope hydraulic parameters,average velocity （V） could effectively predict the sediment yield trend of yellow soil （R2=0.52）,while the Froude number （Fr） was more suitable for predicting the sediment yield dynamics of red soil （R2=0.44）. [Conclusion] This study clarifies the coupling mechanisms of rainfall intensity and slope gradient in soil slope erosion within the Xin’an River basin.It is recommended that rainfall intensity regulation should be strengthened in red soil areas,while slope management should be emphasized in yellow soil areas to curb the exacerbation of soil erosion.
[Objective] The patterns of soil erosion on slopes in the Xin’an River basin were evaluated in order to provide scientific support for regional soil erosion control and sustainable ecological development. [Methods] Through artificial rainfall simulation experiments,the runoff and sediment yield processes,and their differential erosion characteristics were systematically analyzed under different combinations of rainfall intensity and slope gradient for yellow soil and red soil in the river basin,and a quantitative relationship model between hydrodynamic parameters and sediment yield intensity was established. [Results] ① The runoff rate and sediment yield rate on the slopes of both yellow soil and red soil exhibited a steep initial increase during rainfall onset,followed by gradual stabilization,with both increasing with higher rainfall intensity and slope gradient.Red soil slopes demonstrated higher runoff and sediment yield capacity than yellow soil slopes,particularly under a rainfall intensity of 60 mm/h.② Rainfall intensity and slope gradient synergistically exacerbated runoff and sediment erosion,with rainfall intensity dominating the runoff and sediment transport processes on red soil slopes.When the slope gradient reached 15°and rainfall intensity increased to 60 mm/h,the contribution of slope to sediment loss on yellow soil slopes increased to 59.06%.③ A high correlation was observed between runoff and sediment yield on both soil types.Yellow soil slopes generally exhibited a nonlinear relationship characterized by Y=a/[1+exp-b（X-c）].In contrast,due to rapid saturation caused by poor structure,red soil slopes showed synchronous linear growth between sediment yield and runoff yield under a rainfall intensity of 60 mm/h,described by the function Y=a+bX.④ Among the slope hydraulic parameters,average velocity （V） could effectively predict the sediment yield trend of yellow soil （R2=0.52）,while the Froude number （Fr） was more suitable for predicting the sediment yield dynamics of red soil （R2=0.44）. [Conclusion] This study clarifies the coupling mechanisms of rainfall intensity and slope gradient in soil slope erosion within the Xin’an River basin.It is recommended that rainfall intensity regulation should be strengthened in red soil areas,while slope management should be emphasized in yellow soil areas to curb the exacerbation of soil erosion.
2026,46(2):86-99
, DOI: 10.13961/j.cnki.stbctb.2026.02.026
Abstract:
[Objective] The variation patterns of soil moisture and nutrients under different artificial forests in the Loess Plateau were analyzed, and the impact of vegetation restoration on ecosystem structure and function was comprehensively evaluated, in order to provide a scientific basis for the sustainable management of regional artificial forests. [Methods] Typical artificial forest plots in loess regions of Gansu Province were selected as research subjects. Using soil moisture data at a depth of 6 meters and soil nutrient data at a depth of 1 meter collected from various regions between August and September 2022, the distribution characteristics of soil moisture and nutrients under different artificial forests in loess regions were analyzed, and the differences in soil moisture and nutrients under artificial forests across different regions were explored. [Results] ① In different regions, soil moisture profiles under artificial forests gradually decreased with increasing soil depth, indicating a progressive drying process. However, when artificial forests reached maturity or aging stages, soil moisture partially recovered. Geographically, in loess regions of Gansu Province, the average soil moisture under artificial forests showed an increasing trend from north to south and from west to east.② In terms of soil nutrients, most soils in each region were alkaline, with low contents of organic matter, total nitrogen, total phosphorus, and total potassium. Alkali-hydrolyzable nitrogen was highest in Longxi County and lowest in Zhenyuan County. Available phosphorus was highest in Heshui County and lowest in Tianshui County. Available potassium was highest in Heshui County and lowest in Zhenyuan County. [Conclusion] During vegetation restoration in the Loess Plateau, soil moisture and nutrient distribution characteristics of different microtopographies should be considered, and the planting principle of ‘right tree in the right place' should be followed to reasonably configure tree, shrub, and grass planting patterns to improve the soil environment. This approach plays a positive role in ecological management in the Loess Plateau.
[Objective] The variation patterns of soil moisture and nutrients under different artificial forests in the Loess Plateau were analyzed, and the impact of vegetation restoration on ecosystem structure and function was comprehensively evaluated, in order to provide a scientific basis for the sustainable management of regional artificial forests. [Methods] Typical artificial forest plots in loess regions of Gansu Province were selected as research subjects. Using soil moisture data at a depth of 6 meters and soil nutrient data at a depth of 1 meter collected from various regions between August and September 2022, the distribution characteristics of soil moisture and nutrients under different artificial forests in loess regions were analyzed, and the differences in soil moisture and nutrients under artificial forests across different regions were explored. [Results] ① In different regions, soil moisture profiles under artificial forests gradually decreased with increasing soil depth, indicating a progressive drying process. However, when artificial forests reached maturity or aging stages, soil moisture partially recovered. Geographically, in loess regions of Gansu Province, the average soil moisture under artificial forests showed an increasing trend from north to south and from west to east.② In terms of soil nutrients, most soils in each region were alkaline, with low contents of organic matter, total nitrogen, total phosphorus, and total potassium. Alkali-hydrolyzable nitrogen was highest in Longxi County and lowest in Zhenyuan County. Available phosphorus was highest in Heshui County and lowest in Tianshui County. Available potassium was highest in Heshui County and lowest in Zhenyuan County. [Conclusion] During vegetation restoration in the Loess Plateau, soil moisture and nutrient distribution characteristics of different microtopographies should be considered, and the planting principle of ‘right tree in the right place' should be followed to reasonably configure tree, shrub, and grass planting patterns to improve the soil environment. This approach plays a positive role in ecological management in the Loess Plateau.
2026,46(2):100-110
, DOI: 10.13961/j.cnki.stbctb.2026.02.009
Abstract:
[Objective] The dynamic variations in salt ions in coastal saline soil and the differences in maize growth indicators after the addition of different amendments were analyzed in order to provide scientific basis for the further refinement of management measures for desalination and amelioration of coastal saline soil. [Methods] A field-controlled experiment was conducted in the Dafeng coastal reclamation area of Yancheng City,with maize（Liyu 88） as the aboveground crop.A total of ten treatments were set up:control （CK）,and compound fertilizer combined with low ①,medium ②,and high ③ levels of biochar （BC1-BC3）,desulfurized gypsum （DG1-DG3）,and chicken manure （CM1-CM3）.The response characteristics of the physicochemical properties and salt ions of coastal saline soil,as well as maize growth,were analyzed. [Results] ① All amendments improved the soil physicochemical properties,salt ion contents,and ion composition to some extent.However,the addition of desulfurized gypsum was more effective in improving the core physicochemical properties of coastal saline soil,significantly reducing soil pH value and electrical conductivity （EC）.The medium level of desulfurized gypsum（DG2） was most effective in ameliorating soil salt ions,significantly reducing the contents of Na+ and Cl- and the sodium adsorption ratio （SAR）.Additionally,this treatment promoted the accumulation of K+,Ca2+,Mg2+,and SO42-,but had little influence on NO3-.② The promoting effect of maize growth by desulfurized gypsum addition was superior to that of biochar and chicken manure.Notably,the medium level of desulfurized gypsum （DG2） treatment resulted in the highest maize yield among all treatments over the two years,reaching 2.337 t/hm2 and 2.190 t/hm2,respectively. [Conclusion] Among the different amendment levels tested,the medium-level addition of desulfurization gypsum （5 t/hm2）(DG2) is the most effective for enhancing soil desalination and increasing maize yield in coastal saline soil,and can be prioritized for the soil amelioration.
[Objective] The dynamic variations in salt ions in coastal saline soil and the differences in maize growth indicators after the addition of different amendments were analyzed in order to provide scientific basis for the further refinement of management measures for desalination and amelioration of coastal saline soil. [Methods] A field-controlled experiment was conducted in the Dafeng coastal reclamation area of Yancheng City,with maize（Liyu 88） as the aboveground crop.A total of ten treatments were set up:control （CK）,and compound fertilizer combined with low ①,medium ②,and high ③ levels of biochar （BC1-BC3）,desulfurized gypsum （DG1-DG3）,and chicken manure （CM1-CM3）.The response characteristics of the physicochemical properties and salt ions of coastal saline soil,as well as maize growth,were analyzed. [Results] ① All amendments improved the soil physicochemical properties,salt ion contents,and ion composition to some extent.However,the addition of desulfurized gypsum was more effective in improving the core physicochemical properties of coastal saline soil,significantly reducing soil pH value and electrical conductivity （EC）.The medium level of desulfurized gypsum（DG2） was most effective in ameliorating soil salt ions,significantly reducing the contents of Na+ and Cl- and the sodium adsorption ratio （SAR）.Additionally,this treatment promoted the accumulation of K+,Ca2+,Mg2+,and SO42-,but had little influence on NO3-.② The promoting effect of maize growth by desulfurized gypsum addition was superior to that of biochar and chicken manure.Notably,the medium level of desulfurized gypsum （DG2） treatment resulted in the highest maize yield among all treatments over the two years,reaching 2.337 t/hm2 and 2.190 t/hm2,respectively. [Conclusion] Among the different amendment levels tested,the medium-level addition of desulfurization gypsum （5 t/hm2）(DG2) is the most effective for enhancing soil desalination and increasing maize yield in coastal saline soil,and can be prioritized for the soil amelioration.
2026,46(2):111-120,145
, DOI: 10.13961/j.cnki.stbctb.2026.02.013
Abstract:
[Objective] The restoration effects of three measures: fenced enclosure, reseeding and grazing prohibition, on the vegetation characteristics and diversity of different types of degraded grasslands in Ili, Xinjiang were analyzed in order to provide a scientific basis for vegetation restoration of degraded grasslands and sustainable development of regional animal husbandry in Ili. [Methods] Taking the degraded grasslands in Ili, Xinjiang as the research objects, 22 sample plots were selected for field investigation, with free grazing areas serving as the control. The vegetation restoration effects of fenced enclosure, reseeding, and grazing prohibition on six grassland types-mountain meadow, lowland meadow, temperate meadow, temperate desert steppe, alpine meadow, and alpine steppe-were analyzed. [Results] ① After fenced enclosure, vegetation height, coverage, aboveground biomass, and litter biomass of the six grassland types increased significantly by 66%, 50%, 48%, and 52%, respectively, and diversity indices such as the Simpson index also showed significant increases(p<0.05). After reseeding, community vegetation coverage, aboveground biomass, and the Simpson index increased significantly by 57%, 70%, and 10%, respectively(p<0.05). After grazing prohibition, plant species, community vegetation coverage, and aboveground biomass of the mountain meadow increased significantly by 32%, 51%, and 29%, respectively(p<0.05).② Fenced enclosure showed the most prominent restoration response in the temperate desert steppe, with increases in the Simpson index, plant species, community coverage, and aboveground biomass all higher than those in other grassland types. Reseeding had the optimal effect on improving productivity in the alpine meadow, with increases in aboveground biomass and vegetation coverage significantly higher than those in the temperate desert steppe. Grazing prohibition only exhibited short-term restoration effects in the mountain meadow.③ Significant correlations were found between vegetation characteristics and diversity indices of degraded grasslands. Aboveground biomass was extremely significantly positively correlated with litter biomass and vegetation coverage(p<0.01), while aboveground biomass, community vegetation coverage, litter biomass, and plant species were significantly negatively correlated with bare land area(p<0.05).④ All three restoration measures were effective for restoring degraded grasslands in Ili, among which reseeding was the most effective measure for improving community vegetation coverage and aboveground biomass. [Conclusion] Fenced enclosure, reseeding, and grazing prohibition can significantly promote the vegetation restoration of degraded grasslands in Ili, Xinjiang, and the restoration effects of different measures are specific to grassland types. Reseeding has the best effect on improving community productivity.
[Objective] The restoration effects of three measures: fenced enclosure, reseeding and grazing prohibition, on the vegetation characteristics and diversity of different types of degraded grasslands in Ili, Xinjiang were analyzed in order to provide a scientific basis for vegetation restoration of degraded grasslands and sustainable development of regional animal husbandry in Ili. [Methods] Taking the degraded grasslands in Ili, Xinjiang as the research objects, 22 sample plots were selected for field investigation, with free grazing areas serving as the control. The vegetation restoration effects of fenced enclosure, reseeding, and grazing prohibition on six grassland types-mountain meadow, lowland meadow, temperate meadow, temperate desert steppe, alpine meadow, and alpine steppe-were analyzed. [Results] ① After fenced enclosure, vegetation height, coverage, aboveground biomass, and litter biomass of the six grassland types increased significantly by 66%, 50%, 48%, and 52%, respectively, and diversity indices such as the Simpson index also showed significant increases(p<0.05). After reseeding, community vegetation coverage, aboveground biomass, and the Simpson index increased significantly by 57%, 70%, and 10%, respectively(p<0.05). After grazing prohibition, plant species, community vegetation coverage, and aboveground biomass of the mountain meadow increased significantly by 32%, 51%, and 29%, respectively(p<0.05).② Fenced enclosure showed the most prominent restoration response in the temperate desert steppe, with increases in the Simpson index, plant species, community coverage, and aboveground biomass all higher than those in other grassland types. Reseeding had the optimal effect on improving productivity in the alpine meadow, with increases in aboveground biomass and vegetation coverage significantly higher than those in the temperate desert steppe. Grazing prohibition only exhibited short-term restoration effects in the mountain meadow.③ Significant correlations were found between vegetation characteristics and diversity indices of degraded grasslands. Aboveground biomass was extremely significantly positively correlated with litter biomass and vegetation coverage(p<0.01), while aboveground biomass, community vegetation coverage, litter biomass, and plant species were significantly negatively correlated with bare land area(p<0.05).④ All three restoration measures were effective for restoring degraded grasslands in Ili, among which reseeding was the most effective measure for improving community vegetation coverage and aboveground biomass. [Conclusion] Fenced enclosure, reseeding, and grazing prohibition can significantly promote the vegetation restoration of degraded grasslands in Ili, Xinjiang, and the restoration effects of different measures are specific to grassland types. Reseeding has the best effect on improving community productivity.
Chen Yao, Li Yuemei, TA Lingewa, CAO Yiyun, FU Jiaojiao, WANG Xiaomei, WANG Hui, ZHOU Zizhe, SONG Mingdan
2026,46(2):121-131
, DOI: 10.13961/j.cnki.stbctb.2026.02.005
Abstract:
[Objective] The characteristics of agricultural non-point source pollution load in Qinghai Province were analyzed in order to provide important references for formulating agricultural pollution control and ecological protection policies in Qinghai and other ecologically fragile areas. [Methods] Based on statistical data from Qinghai Province from 2009 to 2023,emissions of total nitrogen （TN）,total phosphorus （TP）,chemical oxygen demand （COD）,and ammonia nitrogen （NH3-N） from crop farming,livestock and poultry breeding,and rural domestic sources were estimated using the pollutant generation and discharge coefficient-based method.Sensitivity analysis was conducted by selecting uncertain parameters.The contribution characteristics of pollution sources and pollutants were assessed using the equivalent standard pollution load method. [Results] From 2009 to 2023,the total agricultural non-point source pollution emissions in Qinghai Province showed an increasing trend,rising from 2.17×105 t to 3.65×105 t,an increase of 67.9%.In terms of pollutant type,COD emissions were the largest,ranging from 19.06×104 t to 3.34×105 t and accounting for 87.72%—91.63% of the total emissions.TN emissions ranked second,ranging from 2.23×104 t to 2.52×104 t and accounting for 6.91%～10.28%.Regarding the pollution source structure,livestock and poultry breeding was the primary emission source,with emissions of 1.74×105—3.24×105 t,contributing 80.21%—88.89% of the total emissions.Rural domestic sources ranked second,emitting 2.78×104—2.95×104 t and accounting for 7.71%—12.79%.Sensitivity analysis indicated that livestock and poultry breeding was the most sensitive to regional pollution load regulation,identifying it as the priority for control.The total annual equivalent standard pollution load ranged from 4.42×1010 m3 to 5.69×1010 m3.Among these,TN had the largest equivalent standard pollution load of 2.23×1010 m3 to 2.52×1010 m3,accounting for 44.30%—50.61%,making it the primary pollutant.Livestock and poultry breeding had the largest equivalent standard pollution load of 2.72×1010 m3 to 4.31×1010 m3,accounting for 61.69%—75.78%,identifying it as the dominant pollution source.Considering the equivalent standard pollution load characteristics of both pollution sources and pollutants,TN from livestock and poultry breeding constituted the largest portion of the equivalent standard pollution load at 1.17×1010 to 1.68×1010 m3,representing 26.29%—29.46% of the total. [Conclusion] Addressing agricultural non-point source pollution in Qinghai Province should prioritize the control of livestock and poultry breeding,with TN and COD identified as the key pollutants to control,so as to effectively reduce the regional agricultural pollution load and strengthen the ecological security barrier of the plateau water system.
[Objective] The characteristics of agricultural non-point source pollution load in Qinghai Province were analyzed in order to provide important references for formulating agricultural pollution control and ecological protection policies in Qinghai and other ecologically fragile areas. [Methods] Based on statistical data from Qinghai Province from 2009 to 2023,emissions of total nitrogen （TN）,total phosphorus （TP）,chemical oxygen demand （COD）,and ammonia nitrogen （NH3-N） from crop farming,livestock and poultry breeding,and rural domestic sources were estimated using the pollutant generation and discharge coefficient-based method.Sensitivity analysis was conducted by selecting uncertain parameters.The contribution characteristics of pollution sources and pollutants were assessed using the equivalent standard pollution load method. [Results] From 2009 to 2023,the total agricultural non-point source pollution emissions in Qinghai Province showed an increasing trend,rising from 2.17×105 t to 3.65×105 t,an increase of 67.9%.In terms of pollutant type,COD emissions were the largest,ranging from 19.06×104 t to 3.34×105 t and accounting for 87.72%—91.63% of the total emissions.TN emissions ranked second,ranging from 2.23×104 t to 2.52×104 t and accounting for 6.91%～10.28%.Regarding the pollution source structure,livestock and poultry breeding was the primary emission source,with emissions of 1.74×105—3.24×105 t,contributing 80.21%—88.89% of the total emissions.Rural domestic sources ranked second,emitting 2.78×104—2.95×104 t and accounting for 7.71%—12.79%.Sensitivity analysis indicated that livestock and poultry breeding was the most sensitive to regional pollution load regulation,identifying it as the priority for control.The total annual equivalent standard pollution load ranged from 4.42×1010 m3 to 5.69×1010 m3.Among these,TN had the largest equivalent standard pollution load of 2.23×1010 m3 to 2.52×1010 m3,accounting for 44.30%—50.61%,making it the primary pollutant.Livestock and poultry breeding had the largest equivalent standard pollution load of 2.72×1010 m3 to 4.31×1010 m3,accounting for 61.69%—75.78%,identifying it as the dominant pollution source.Considering the equivalent standard pollution load characteristics of both pollution sources and pollutants,TN from livestock and poultry breeding constituted the largest portion of the equivalent standard pollution load at 1.17×1010 to 1.68×1010 m3,representing 26.29%—29.46% of the total. [Conclusion] Addressing agricultural non-point source pollution in Qinghai Province should prioritize the control of livestock and poultry breeding,with TN and COD identified as the key pollutants to control,so as to effectively reduce the regional agricultural pollution load and strengthen the ecological security barrier of the plateau water system.
2026,46(2):132-145
, DOI: 10.13961/j.cnki.stbctb.2026.02.006
Abstract:
[Objective] The spatiotemporal evolution characteristics of mountain-oasis-desert ecosystem service value （ESV） in the Manas River basin from 2000 to 2023,as well as the differences across various landforms were analyzed in order to provide a scientific basis for optimizing land use planning and ecological protection in the river basin,and for formulating regional zoning management and development strategies. [Methods] Land use change information was extracted from remote sensing data spanning from 2000 to 2023.The equivalent factor method was used to assess the ESV across the river basin.Subsequently,correlation analysis was conducted to examine the spatiotemporal evolution characteristics of ESV and its relationships with land use changes. [Results] ① Land use dynamics were characterized by significant cropland expansion （net increase of 3 267.19 km2,total transfer-in of 3 621.11 km2） and grassland contraction （net loss of 3 493.61 km2）.Cropland expansion was predominant in the oasis zone,while the mountainous zone exhibited degradation of natural ecological land.② The total ESV of the river basin exhibited an overall downward trend,with a cumulative loss of 2.74×1010 yuan over 23 years.A particularly sharp decline （33.90%） was observed from 2005 to 2010.③ Among ESs categories,hydrological regulation value experienced the greatest reduction (1.93×1010 yuan),while the values of food production,raw material supply,and nutrient cycling increased.④ Spatially,high-ESV zones were concentrated in the southern mountainous glacier region and the Manas Lake region,while desert zones were identified as lowESV zones.The ESV across the three geomorphic zones ranked as follows:oasis zone>mountainous zone>desert zone. [Conclusion] Agricultural expansion-driven land use transition is identified as the primary factor exacerbating the degradation of ecosystem service functions in the Manas River basin.It is recommended to establish geomorphology-based zonal regulation mechanisms.Emphasis should be placed on mitigating the tradeoff between food production and other ecological functions in the oasis zone,ensuring the rational allocation and efficient utilization of scarce water resources,and promoting the orderly management of ecosystem services and the coordinated development of ecology and economy in this arid region.
[Objective] The spatiotemporal evolution characteristics of mountain-oasis-desert ecosystem service value （ESV） in the Manas River basin from 2000 to 2023,as well as the differences across various landforms were analyzed in order to provide a scientific basis for optimizing land use planning and ecological protection in the river basin,and for formulating regional zoning management and development strategies. [Methods] Land use change information was extracted from remote sensing data spanning from 2000 to 2023.The equivalent factor method was used to assess the ESV across the river basin.Subsequently,correlation analysis was conducted to examine the spatiotemporal evolution characteristics of ESV and its relationships with land use changes. [Results] ① Land use dynamics were characterized by significant cropland expansion （net increase of 3 267.19 km2,total transfer-in of 3 621.11 km2） and grassland contraction （net loss of 3 493.61 km2）.Cropland expansion was predominant in the oasis zone,while the mountainous zone exhibited degradation of natural ecological land.② The total ESV of the river basin exhibited an overall downward trend,with a cumulative loss of 2.74×1010 yuan over 23 years.A particularly sharp decline （33.90%） was observed from 2005 to 2010.③ Among ESs categories,hydrological regulation value experienced the greatest reduction (1.93×1010 yuan),while the values of food production,raw material supply,and nutrient cycling increased.④ Spatially,high-ESV zones were concentrated in the southern mountainous glacier region and the Manas Lake region,while desert zones were identified as lowESV zones.The ESV across the three geomorphic zones ranked as follows:oasis zone>mountainous zone>desert zone. [Conclusion] Agricultural expansion-driven land use transition is identified as the primary factor exacerbating the degradation of ecosystem service functions in the Manas River basin.It is recommended to establish geomorphology-based zonal regulation mechanisms.Emphasis should be placed on mitigating the tradeoff between food production and other ecological functions in the oasis zone,ensuring the rational allocation and efficient utilization of scarce water resources,and promoting the orderly management of ecosystem services and the coordinated development of ecology and economy in this arid region.
2026,46(2):146-154,259
, DOI: 10.13961/j.cnki.stbctb.2026.02.039
Abstract:
[Objective] The spatiotemporal evolution trends and driving mechanisms of vegetation cover in the Dongting Lake area from 2000 to 2022 were investigated, in order to identify key influencing factors and their contribution levels, and provide scientific references for regional ecological restoration and sustainable development. [Methods] Based on the Google Earth Engine cloud platform, the kernel normalized difference vegetation index(kNDVI) was constructed using MOD13A1 V6 data. The Theil-Sen Median trend analysis, Mann-Kendall test, Hurst index, and structural equation model(SEM) were integrated to systematically analyze the spatiotemporal variation characteristics of kNDVI in the Dongting Lake area. The coupling mechanisms among climatic factors, human activities, and topographic factors were comprehensively assessed. [Results] ① From 2000 to 2022, the kNDVI in the Dongting Lake area showed an overall increasing trend(0.025/10 a, p<0.001), with a spatial pattern of higher values in the eastern, southern, and western parts and lower values in the central and northern parts.② Vegetation cover exhibited persistent improvement, with the Hurst index predicting that persistently improved areas accounted for 57.87%, persistently stable areas for 38.97%, and persistently degraded areas for only 3.61%.③ The SEM demonstrated that the total effects of driving factors on kNDVI changes were ranked as follows: nighttime light > population density > elevation > slope > land use > soil moisture > temperature > aspect > precipitation. [Conclusion] Over the past 23 years, vegetation cover in the Dongting Lake area has shown overall improvement. Human activities are the primary negative driving factor of vegetation change, climatic factors play a positive promoting role, and the effects of topographic factors remain relatively limited.
[Objective] The spatiotemporal evolution trends and driving mechanisms of vegetation cover in the Dongting Lake area from 2000 to 2022 were investigated, in order to identify key influencing factors and their contribution levels, and provide scientific references for regional ecological restoration and sustainable development. [Methods] Based on the Google Earth Engine cloud platform, the kernel normalized difference vegetation index(kNDVI) was constructed using MOD13A1 V6 data. The Theil-Sen Median trend analysis, Mann-Kendall test, Hurst index, and structural equation model(SEM) were integrated to systematically analyze the spatiotemporal variation characteristics of kNDVI in the Dongting Lake area. The coupling mechanisms among climatic factors, human activities, and topographic factors were comprehensively assessed. [Results] ① From 2000 to 2022, the kNDVI in the Dongting Lake area showed an overall increasing trend(0.025/10 a, p<0.001), with a spatial pattern of higher values in the eastern, southern, and western parts and lower values in the central and northern parts.② Vegetation cover exhibited persistent improvement, with the Hurst index predicting that persistently improved areas accounted for 57.87%, persistently stable areas for 38.97%, and persistently degraded areas for only 3.61%.③ The SEM demonstrated that the total effects of driving factors on kNDVI changes were ranked as follows: nighttime light > population density > elevation > slope > land use > soil moisture > temperature > aspect > precipitation. [Conclusion] Over the past 23 years, vegetation cover in the Dongting Lake area has shown overall improvement. Human activities are the primary negative driving factor of vegetation change, climatic factors play a positive promoting role, and the effects of topographic factors remain relatively limited.
2026,46(2):155-166
, DOI: 10.13961/j.cnki.stbctb.2026.02.027
Abstract:
[Objective] The formation mechanisms of clustered slope debris flows in Mentougou District, Beijing City, were analyzed in order to provide a theoretical basis for the prevention and control of this type of deloris flow. [Methods] A multi-source data fusion approach combined with field verification was adopted.① Maxar WorldView 0.3 m high-resolution remote sensing images were applied for the first time to identify the spatial distribution, flow paths, and depositional characteristics of the group-occurring slope debris flows.② UAV oblique photogrammetry was used to obtain high-precision topographic data of typical disaster sites. [Results] The group-occurring slope debris flows in Wangping Village resulted from the triple coupling of ‘geological environment basement-extreme rainfall-human engineering disturbance'. Geologically controlled by an anticline structure, with slope gradients ranging from 19.49° to 36.54°, the ‘dual structure' formed by residual-slope deposits and bedrock provided material sources and sliding boundaries for the debris flows. Extreme rainfall(cumulative rainfall >700 mm, maximum rainfall intensity of 111.8 mm/h) led to soil saturation and triggered the flows. Human engineering disturbances altered slope topography and reduced slope stability. The disasters were concentrated along the anticlinal axis, characterized by small scale, high group occurrence, and strong concealment. [Conclusion] An integrated model of ‘combining prevention and control, ecological-economic synergy' is proposed.① Flexible barriers are deployed in the material source initiation areas and upstream of protected objects(residential areas, railways), saving 70% of the investment compared to traditional reinforced concrete barrier dams.② The application of geocells combined with grass planting measures in erosional gullies saves 52% of costs compared to traditional stone masonry retaining walls and reduce soil loss by over 90%.
[Objective] The formation mechanisms of clustered slope debris flows in Mentougou District, Beijing City, were analyzed in order to provide a theoretical basis for the prevention and control of this type of deloris flow. [Methods] A multi-source data fusion approach combined with field verification was adopted.① Maxar WorldView 0.3 m high-resolution remote sensing images were applied for the first time to identify the spatial distribution, flow paths, and depositional characteristics of the group-occurring slope debris flows.② UAV oblique photogrammetry was used to obtain high-precision topographic data of typical disaster sites. [Results] The group-occurring slope debris flows in Wangping Village resulted from the triple coupling of ‘geological environment basement-extreme rainfall-human engineering disturbance'. Geologically controlled by an anticline structure, with slope gradients ranging from 19.49° to 36.54°, the ‘dual structure' formed by residual-slope deposits and bedrock provided material sources and sliding boundaries for the debris flows. Extreme rainfall(cumulative rainfall >700 mm, maximum rainfall intensity of 111.8 mm/h) led to soil saturation and triggered the flows. Human engineering disturbances altered slope topography and reduced slope stability. The disasters were concentrated along the anticlinal axis, characterized by small scale, high group occurrence, and strong concealment. [Conclusion] An integrated model of ‘combining prevention and control, ecological-economic synergy' is proposed.① Flexible barriers are deployed in the material source initiation areas and upstream of protected objects(residential areas, railways), saving 70% of the investment compared to traditional reinforced concrete barrier dams.② The application of geocells combined with grass planting measures in erosional gullies saves 52% of costs compared to traditional stone masonry retaining walls and reduce soil loss by over 90%.
2026,46(2):167-177
, DOI: 10.13961/j.cnki.stbctb.2026.02.031
Abstract:
[Objective] The changes in ecological environment quality and their driving factors in the Yellow River Source Park of the Three-River-Source National Park from 2000 to 2024 were investigated in order to provide a scientific basis for ecological protection and sustainable development in this region. [Methods] Based on the Google Earth Engine platform, MODIS images were acquired and processed to construct remote sensing ecological index(RSEI) for monitoring changes in ecological environment quality in the Yellow River Source Park from 2000 to 2024. Additionally, the geodetector model was utilized to quantitatively analyze the effects of climate, topography, and human activities on these changes. [Results] ① From 2000 to 2024, the annual mean RSEI in the Yellow River Source Park ranged between 0.527 and 0.689, showing a fluctuating upward trend with an average increase rate of approximately 0.003 1 per year. Spatially, the ecological environment quality exhibited a distribution pattern of ‘poor in the north and good in the south'.② The area with improved ecological environment quality accounted for 81.50%, which was significantly higher than the degraded area(9.38%), indicating remarkable ecological improvement.③ In single-factor detection, precipitation had the strongest explanatory power, followed by temperature and DEM. In interaction detection, the interaction between precipitation and temperature had the greatest influence, followed by the interaction between precipitation and DEM. The influence of climate and topographic factors gradually weakened, while the impact of human activities progressively strengthened. [Conclusion] From 2000 to 2024, the ecological environment quality in the Yellow River Source Park continuously improved. Precipitation, temperature, and DEM are the main driving factors affecting ecological quality, and the ecological protection and restoration efforts undertaken by humans have achieved remarkable results. Future work should focus on gradually advancing ecological management in key and challenging areas while ensuring the continuous improvement of the ecological environment in the study area.
[Objective] The changes in ecological environment quality and their driving factors in the Yellow River Source Park of the Three-River-Source National Park from 2000 to 2024 were investigated in order to provide a scientific basis for ecological protection and sustainable development in this region. [Methods] Based on the Google Earth Engine platform, MODIS images were acquired and processed to construct remote sensing ecological index(RSEI) for monitoring changes in ecological environment quality in the Yellow River Source Park from 2000 to 2024. Additionally, the geodetector model was utilized to quantitatively analyze the effects of climate, topography, and human activities on these changes. [Results] ① From 2000 to 2024, the annual mean RSEI in the Yellow River Source Park ranged between 0.527 and 0.689, showing a fluctuating upward trend with an average increase rate of approximately 0.003 1 per year. Spatially, the ecological environment quality exhibited a distribution pattern of ‘poor in the north and good in the south'.② The area with improved ecological environment quality accounted for 81.50%, which was significantly higher than the degraded area(9.38%), indicating remarkable ecological improvement.③ In single-factor detection, precipitation had the strongest explanatory power, followed by temperature and DEM. In interaction detection, the interaction between precipitation and temperature had the greatest influence, followed by the interaction between precipitation and DEM. The influence of climate and topographic factors gradually weakened, while the impact of human activities progressively strengthened. [Conclusion] From 2000 to 2024, the ecological environment quality in the Yellow River Source Park continuously improved. Precipitation, temperature, and DEM are the main driving factors affecting ecological quality, and the ecological protection and restoration efforts undertaken by humans have achieved remarkable results. Future work should focus on gradually advancing ecological management in key and challenging areas while ensuring the continuous improvement of the ecological environment in the study area.
2026,46(2):178-190
, DOI: 10.13961/j.cnki.stbctb.2026.02.037
Abstract:
[Objective] The variation characteristics of different precipitation grades in Jilin Province from 1960 to 2024 were analyzed in order to provide a scientific basis for the sustainable management of water and soil resources and the prevention and control of drought and flood disaster risks in the province. [Methods] Based on daily precipitation data from 47 meteorological stations in Jilin Province from 1960 to 2024, methods including linear trend analysis, correlation analysis, and Hurst exponent were employed to investigate the spatiotemporal variation characteristics and trend persistence of precipitation amount, precipitation days, and precipitation intensity across different grades. [Results] During the study period, the precipitation structure in Jilin Province underwent significant changes. Both light precipitation amount and light precipitation days showed decreasing trends(p<0.05), while rainstorm amount and rainstorm days increased significantly(p<0.05). Precipitation intensity exhibited an increasing trend for all grades except for heavy rainstorm intensity, which showed a slight decline. Moderate rain contributed the most to total precipitation(33.44%), followed by light rain(33.14%). Light rain had the highest occurrence frequency(83.11%). However, both its contribution and occurrence frequency showed decreasing trends, whereas those of rainstorms increased significantly. Changes in total precipitation amount were mainly influenced by heavy rain, changes in total precipitation days were dominated by light rain days, and total precipitation intensity was closely related to the amount and days of heavy rain and rainstorms. Spatially, precipitation amounts and days for all grades exhibited a pattern of higher values in the southeast and lower values in the northwest, while precipitation intensity showed considerable spatial heterogeneity across different grades. Notably, the transformation of precipitation structure characterized by increased rainstorm events and decreased light rain events was widespread across the province, albeit with regional variations in its intensity. The interaction of geofactors significantly controlled the spatial differentiation of light and moderate precipitation amounts and days. In contrast, precipitation of rainstorm grade and above was more influenced by local weather systems, showing weaker correlations with geofactors. Hurst exponent analysis indicated that, except for the future trend of heavy rainstorm intensity which might reverse, the historical change trends of other precipitation indicators all exhibited strong persistence. [Conclusion] The precipitation structure in Jilin Province is evolving towards a more extreme pattern characterized by increased rainstorm events and decreased light rain events. Greater attention should be paid to this issue in future research and policy-making related to regional water-soil security and meteorological disaster prevention.
[Objective] The variation characteristics of different precipitation grades in Jilin Province from 1960 to 2024 were analyzed in order to provide a scientific basis for the sustainable management of water and soil resources and the prevention and control of drought and flood disaster risks in the province. [Methods] Based on daily precipitation data from 47 meteorological stations in Jilin Province from 1960 to 2024, methods including linear trend analysis, correlation analysis, and Hurst exponent were employed to investigate the spatiotemporal variation characteristics and trend persistence of precipitation amount, precipitation days, and precipitation intensity across different grades. [Results] During the study period, the precipitation structure in Jilin Province underwent significant changes. Both light precipitation amount and light precipitation days showed decreasing trends(p<0.05), while rainstorm amount and rainstorm days increased significantly(p<0.05). Precipitation intensity exhibited an increasing trend for all grades except for heavy rainstorm intensity, which showed a slight decline. Moderate rain contributed the most to total precipitation(33.44%), followed by light rain(33.14%). Light rain had the highest occurrence frequency(83.11%). However, both its contribution and occurrence frequency showed decreasing trends, whereas those of rainstorms increased significantly. Changes in total precipitation amount were mainly influenced by heavy rain, changes in total precipitation days were dominated by light rain days, and total precipitation intensity was closely related to the amount and days of heavy rain and rainstorms. Spatially, precipitation amounts and days for all grades exhibited a pattern of higher values in the southeast and lower values in the northwest, while precipitation intensity showed considerable spatial heterogeneity across different grades. Notably, the transformation of precipitation structure characterized by increased rainstorm events and decreased light rain events was widespread across the province, albeit with regional variations in its intensity. The interaction of geofactors significantly controlled the spatial differentiation of light and moderate precipitation amounts and days. In contrast, precipitation of rainstorm grade and above was more influenced by local weather systems, showing weaker correlations with geofactors. Hurst exponent analysis indicated that, except for the future trend of heavy rainstorm intensity which might reverse, the historical change trends of other precipitation indicators all exhibited strong persistence. [Conclusion] The precipitation structure in Jilin Province is evolving towards a more extreme pattern characterized by increased rainstorm events and decreased light rain events. Greater attention should be paid to this issue in future research and policy-making related to regional water-soil security and meteorological disaster prevention.
2026,46(2):225-236
, DOI: 10.13961/j.cnki.stbctb.2026.02.010
Abstract:
[Objective] The spatiotemporal distribution of abandoned farmland in the core black soil protection area of Jilin Province from 2000 to 2023 was analyzed, the main driving factors of farmland abandonment were clarified, and the soil and water conservation effects of abandoned farmland are evaluated, in order to provide a theoretical basis for remote sensing monitoring of abandoned farmland and research on soil and water conservation effects in similar regions. [Methods] Based on the Google Earth Engine（GEE） platform and Landsat long-term time-series imagery, this study integrated multidimensional characteristics and combined random forest with LandTrendr change detection method to map the spatiotemporal distribution of abandoned farmland in the study area. Additionally, the key driving factors were analyzed using the geodetector. Finally, a comprehensive evaluation of the soil and water conservation effects of abandoned farmland was conducted using a combination weighting method based on AHP-EM-product normalization. [Results] ① The RF-LT model achieved an overall accuracy greater than 85% and a Kappa coefficient of at least 0.8, indicating high classification accuracy and good overall performance.② The area of abandoned farmland initially increased and then experienced a fluctuating decline after peaking at 459 km2 in 2013. Spatially, it first increased then decreased, and finally showed local increases, with relatively scattered distribution of abandoned farmland.③ Night-time light intensity, average parcel area, and elevation had high explanatory power for farmland abandonment, with q-values all exceeding 0.4. Furthermore, the interaction between slope and average parcel area was the most significant, with a q-value of 0.997.④ The comprehensive scores of soil and water conservation effects for abandoned farmland in the study area with abandonment durations of 5, 10, 15, 20, and over 20 years were 0.388 6, 0.477 3, 0.801 4, 0.604 4, and 0.443 8, respectively, showing an initial increase followed by a decrease. [Conclusion] The moderate abandonment within a certain period has a positive impact on soil and water conservation, specifically reflected in the improvement of ecological diversity and soil properties.
[Objective] The spatiotemporal distribution of abandoned farmland in the core black soil protection area of Jilin Province from 2000 to 2023 was analyzed, the main driving factors of farmland abandonment were clarified, and the soil and water conservation effects of abandoned farmland are evaluated, in order to provide a theoretical basis for remote sensing monitoring of abandoned farmland and research on soil and water conservation effects in similar regions. [Methods] Based on the Google Earth Engine（GEE） platform and Landsat long-term time-series imagery, this study integrated multidimensional characteristics and combined random forest with LandTrendr change detection method to map the spatiotemporal distribution of abandoned farmland in the study area. Additionally, the key driving factors were analyzed using the geodetector. Finally, a comprehensive evaluation of the soil and water conservation effects of abandoned farmland was conducted using a combination weighting method based on AHP-EM-product normalization. [Results] ① The RF-LT model achieved an overall accuracy greater than 85% and a Kappa coefficient of at least 0.8, indicating high classification accuracy and good overall performance.② The area of abandoned farmland initially increased and then experienced a fluctuating decline after peaking at 459 km2 in 2013. Spatially, it first increased then decreased, and finally showed local increases, with relatively scattered distribution of abandoned farmland.③ Night-time light intensity, average parcel area, and elevation had high explanatory power for farmland abandonment, with q-values all exceeding 0.4. Furthermore, the interaction between slope and average parcel area was the most significant, with a q-value of 0.997.④ The comprehensive scores of soil and water conservation effects for abandoned farmland in the study area with abandonment durations of 5, 10, 15, 20, and over 20 years were 0.388 6, 0.477 3, 0.801 4, 0.604 4, and 0.443 8, respectively, showing an initial increase followed by a decrease. [Conclusion] The moderate abandonment within a certain period has a positive impact on soil and water conservation, specifically reflected in the improvement of ecological diversity and soil properties.
2026,46(2):237-247
, DOI: 10.13961/j.cnki.stbctb.2026.02.020
Abstract:
[Objective] The non-stationary dynamic characteristics of surface soil moisture under microtopographic conditions were systematically analyzed in order to provide important scientific support for optimizing water management strategies and constructing self-sustaining ecosystems in ecological restoration of arid regions. [Methods] Based on continuous monitoring data and the Pettitt test,abrupt change points of soil moisture during the frozen soil thawing period were quantitatively identified and stages were divided.The regulatory mechanisms of microtopography on soil moisture dynamics at different depths were revealed,and a snow-topography-moisturesoil response chain was constructed.The ARIMA （1,1,1） model was applied to predict soil moisture trends. [Results] ① During the early thawing period,shallow soil moisture （10 cm and 20 cm） in the restored area increased significantly,with maximum values of 0.312 m3/m3 and 0.199 m3/m3,and average increases of 22.1% and 19.4%,respectively.In the control area,the maximum values were 0.231 m3/m3 and 0.186 m3/m3,with average increases of only 14.6% and 12.5%.Moisture recharge in soil layers at 30 cm and below was relatively weak,with no significant difference between the restored and control areas.②During the mid-thawing period,soil moisture at 10 cm and 20 cm in the restored area gradually decreased but remained higher than that in the control area.Moisture at 30 cm and 40 cm in the restored area increased slowly,with maximum values of 0.155 m3/m3 and 0.139 m3/m3,respectively,while in the control area,the values were 0.127 m3/m3 and 0.129 m3/m3.③During the late thawing period,soil moisture stabilized,while groundwater moisture decreased.Shallow soil moisture in the restored area showed relatively large fluctuations,enabling ephemeral plants to rapidly complete their life cycle by utilizing moisture pulses.The ARIMA （1,1,1） model performed well in predicting soil moisture at depths of 10 cm and 20 cm,with Nash-Sutcliffe efficiency coefficients of 0.85 and 0.82,respectively,indicating high predictive accuracy. [Conclusion] Microtopography restoration significantly enhances shallow soil moisture during the seasonal frozen soil thawing period,improving water availability for the early spring germination of ephemeral plants.Level trenches,as a near-natural restoration measure,demonstrate good ecological regulation potential and promotion value.
[Objective] The non-stationary dynamic characteristics of surface soil moisture under microtopographic conditions were systematically analyzed in order to provide important scientific support for optimizing water management strategies and constructing self-sustaining ecosystems in ecological restoration of arid regions. [Methods] Based on continuous monitoring data and the Pettitt test,abrupt change points of soil moisture during the frozen soil thawing period were quantitatively identified and stages were divided.The regulatory mechanisms of microtopography on soil moisture dynamics at different depths were revealed,and a snow-topography-moisturesoil response chain was constructed.The ARIMA （1,1,1） model was applied to predict soil moisture trends. [Results] ① During the early thawing period,shallow soil moisture （10 cm and 20 cm） in the restored area increased significantly,with maximum values of 0.312 m3/m3 and 0.199 m3/m3,and average increases of 22.1% and 19.4%,respectively.In the control area,the maximum values were 0.231 m3/m3 and 0.186 m3/m3,with average increases of only 14.6% and 12.5%.Moisture recharge in soil layers at 30 cm and below was relatively weak,with no significant difference between the restored and control areas.②During the mid-thawing period,soil moisture at 10 cm and 20 cm in the restored area gradually decreased but remained higher than that in the control area.Moisture at 30 cm and 40 cm in the restored area increased slowly,with maximum values of 0.155 m3/m3 and 0.139 m3/m3,respectively,while in the control area,the values were 0.127 m3/m3 and 0.129 m3/m3.③During the late thawing period,soil moisture stabilized,while groundwater moisture decreased.Shallow soil moisture in the restored area showed relatively large fluctuations,enabling ephemeral plants to rapidly complete their life cycle by utilizing moisture pulses.The ARIMA （1,1,1） model performed well in predicting soil moisture at depths of 10 cm and 20 cm,with Nash-Sutcliffe efficiency coefficients of 0.85 and 0.82,respectively,indicating high predictive accuracy. [Conclusion] Microtopography restoration significantly enhances shallow soil moisture during the seasonal frozen soil thawing period,improving water availability for the early spring germination of ephemeral plants.Level trenches,as a near-natural restoration measure,demonstrate good ecological regulation potential and promotion value.
2026,46(2):248-259
, DOI: 10.13961/j.cnki.stbctb.2026.02.018
Abstract:
[Objective] A comprehensive quantitative evaluation of the overall effectiveness and that under different value realization models of typical cases in northwest China was conducted, and the feasibility of the evaluation indicator system for evaluating the effectiveness of typical cases was further verified, in order to provide references for other regions to extract relevant typical cases. [Methods] 29 typical cases in northwest China were selected as the study objects. A three-dimensional evaluation system encompassing ‘resources-mechanismsbenefits' was established. The entropy value method and the comprehensive index method were used to calculate the overall effectiveness, stage-specific effectiveness, and effectiveness of different models in realizing ecological product value. [Results] ① The overall effectiveness of ecological product value realization varied significantly across cases, with 16 cases falling below the average score of 36.47, indicating that there was still room for improvement in value realization. The synergy among multiple mechanisms constituted the core stage in the process of ecological product value realization. The output of comprehensive benefits was influenced by factors such as policy time lags, which resulted in relatively slow performance and lower scores.② All existing ecological product value realization models incorporated industrialization pathways. The effectiveness scores for the ‘transaction+industrialization' ‘restoration+transaction+industrialization' and ‘compensation+industrialization' models were 46.27, 41.72, and 38.62, respectively, indicating relatively good performance.③ Both the ‘industrialization' and ‘restoration+industrialization' models prioritized multi-mechanism synergy as their primary achievement, while the ‘compensation+industrialization' model achieved the highest score(48.86) in comprehensive benefit output. [Conclusion] The realization of ecological product value in northwest China has achieved phased results, yet it still faces the challenge of relatively low comprehensive benefit output. In the subsequent efforts to promote ecological product value realization, it is essential to be guided by the goal of maximizing comprehensive benefits, establish and improve multi-mechanism synergy, and continuously optimize the market transaction environment.
[Objective] A comprehensive quantitative evaluation of the overall effectiveness and that under different value realization models of typical cases in northwest China was conducted, and the feasibility of the evaluation indicator system for evaluating the effectiveness of typical cases was further verified, in order to provide references for other regions to extract relevant typical cases. [Methods] 29 typical cases in northwest China were selected as the study objects. A three-dimensional evaluation system encompassing ‘resources-mechanismsbenefits' was established. The entropy value method and the comprehensive index method were used to calculate the overall effectiveness, stage-specific effectiveness, and effectiveness of different models in realizing ecological product value. [Results] ① The overall effectiveness of ecological product value realization varied significantly across cases, with 16 cases falling below the average score of 36.47, indicating that there was still room for improvement in value realization. The synergy among multiple mechanisms constituted the core stage in the process of ecological product value realization. The output of comprehensive benefits was influenced by factors such as policy time lags, which resulted in relatively slow performance and lower scores.② All existing ecological product value realization models incorporated industrialization pathways. The effectiveness scores for the ‘transaction+industrialization' ‘restoration+transaction+industrialization' and ‘compensation+industrialization' models were 46.27, 41.72, and 38.62, respectively, indicating relatively good performance.③ Both the ‘industrialization' and ‘restoration+industrialization' models prioritized multi-mechanism synergy as their primary achievement, while the ‘compensation+industrialization' model achieved the highest score(48.86) in comprehensive benefit output. [Conclusion] The realization of ecological product value in northwest China has achieved phased results, yet it still faces the challenge of relatively low comprehensive benefit output. In the subsequent efforts to promote ecological product value realization, it is essential to be guided by the goal of maximizing comprehensive benefits, establish and improve multi-mechanism synergy, and continuously optimize the market transaction environment.
2026,46(2):270-283,305
, DOI: 10.13961/j.cnki.stbctb.2026.02.025
Abstract:
[Objective] The impact of seasonal drought on water use efficiency(WUE) of ecosystems and its carbon-water coupling mechanisms was analyzed in order to provide a scientific basis for enhancing vegetation carbon sequestration capacity, optimizing water resource allocation, and formulating ecosystem protection strategies. [Methods] Based on data from China's terrestrial ecosystems from 2001 to 2023, the spatiotemporal dynamics and seasonal patterns of WUE and its responses to drought were systematically assessed using trend and correlation analyses. By integrating the XGBoost-SHAP interpretable machine learning model with LOWESS fitting, the nonlinear response characteristics and threshold effects of drought stress factors were further quantified. [Results] The frequency of extreme drought events and the WUE of vegetation in China both exhibited pronounced seasonal patterns. Extreme droughts occurred most frequently and extensively in spring, while WUE reached its peak in summer. Its seasonal variations were jointly driven by gross primary productivity(GPP) and evapotranspiration in spring, gradually shifting to a ‘ GPP-dominated' pattern in summer and autumn, with a decreasing gradient from south to north. In spring, WUE was co-regulated by soil moisture and evapotranspiration, whereas in summer and autumn, it was primarily controlled by soil moisture. [Conclusion] The impact of drought on WUE exhibits significant seasonal differences and is primarily constrained by soil moisture conditions. Enhancing water management during the key controlling seasons and optimizing vegetation structure are essential strategies for improving ecosystem drought resilience and mitigating climate change and ecological risks.
[Objective] The impact of seasonal drought on water use efficiency(WUE) of ecosystems and its carbon-water coupling mechanisms was analyzed in order to provide a scientific basis for enhancing vegetation carbon sequestration capacity, optimizing water resource allocation, and formulating ecosystem protection strategies. [Methods] Based on data from China's terrestrial ecosystems from 2001 to 2023, the spatiotemporal dynamics and seasonal patterns of WUE and its responses to drought were systematically assessed using trend and correlation analyses. By integrating the XGBoost-SHAP interpretable machine learning model with LOWESS fitting, the nonlinear response characteristics and threshold effects of drought stress factors were further quantified. [Results] The frequency of extreme drought events and the WUE of vegetation in China both exhibited pronounced seasonal patterns. Extreme droughts occurred most frequently and extensively in spring, while WUE reached its peak in summer. Its seasonal variations were jointly driven by gross primary productivity(GPP) and evapotranspiration in spring, gradually shifting to a ‘ GPP-dominated' pattern in summer and autumn, with a decreasing gradient from south to north. In spring, WUE was co-regulated by soil moisture and evapotranspiration, whereas in summer and autumn, it was primarily controlled by soil moisture. [Conclusion] The impact of drought on WUE exhibits significant seasonal differences and is primarily constrained by soil moisture conditions. Enhancing water management during the key controlling seasons and optimizing vegetation structure are essential strategies for improving ecosystem drought resilience and mitigating climate change and ecological risks.
2026,46(2):284-294
, DOI: 10.13961/j.cnki.stbctb.2026.02.032
Abstract:
[Objective] The positive role of ecological management projects in the ‘carbon reduction-pollution reduction-green expansion-economic growth' system of the urban agglomeration in the middle reaches of the Yangtze River was analyzed, and its spatiotemporal evolution patterns, influencing mechanisms, and future development trends were systematically revealed, in order to provide a scientific basis for the regional coordinated advancement of carbon reduction, pollution reduction, green expansion, and economic growth. [Methods] Based on data from 2003 to 2023, an evaluation system comprising 30 indicators was constructed. The entropy method, coupling coordination degree model, spatiotemporal geographically weighted regression model, and ARIMA prediction model were comprehensively employed to systematically analyze the spatiotemporal evolution patterns, driving mechanisms, and future trends of coupling coordination in this region. [Results] The results showed that:① the mean coupling coordination degree(0.44—0.75) showed an upward trend during the study period. However, significant inter-provincial and intra-provincial differences were observed. Hubei Province had the highest coupling coordination degree(0.82), while Hunan Province lagged relatively behind(0.74).② The driving factors exhibited spatiotemporal heterogeneity. The level of digital economy and industrial structure upgrading served as a positive driving factor, while the contribution of technological investment was not significant. Government intervention exerted a certain inhibitory effect due to the conflict between administrative governance and marketization.③ The high consistency between the actual and predicted values in 2023 confirmed the reliability of the future trend prediction. It was projected that by 2030, the coupling coordination degree of core cities such as Wuhan, Changsha, and Nanchang would approach or exceed 0.85. However, the growth rate of small and medium-sized cities would be slow, and inter-provincial disparities would narrow. [Conclusion] From 2003 to 2023, the coupling and coordinated development level of carbon reduction, pollution reduction, green expansion, and economic growth in the region has been continuously increasing and is expected to maintain an upward trend. Significant inter-provincial and intra-provincial differences are observed in development levels within the region. It is recommended to strengthen the radiating role of core cities, promote industrial transformation and the application of scientific and technological achievements, improve the ecological compensation mechanisms, and implement targeted policies based on the spatiotemporal differences of driving factors to facilitate regional coordinated development.
[Objective] The positive role of ecological management projects in the ‘carbon reduction-pollution reduction-green expansion-economic growth' system of the urban agglomeration in the middle reaches of the Yangtze River was analyzed, and its spatiotemporal evolution patterns, influencing mechanisms, and future development trends were systematically revealed, in order to provide a scientific basis for the regional coordinated advancement of carbon reduction, pollution reduction, green expansion, and economic growth. [Methods] Based on data from 2003 to 2023, an evaluation system comprising 30 indicators was constructed. The entropy method, coupling coordination degree model, spatiotemporal geographically weighted regression model, and ARIMA prediction model were comprehensively employed to systematically analyze the spatiotemporal evolution patterns, driving mechanisms, and future trends of coupling coordination in this region. [Results] The results showed that:① the mean coupling coordination degree(0.44—0.75) showed an upward trend during the study period. However, significant inter-provincial and intra-provincial differences were observed. Hubei Province had the highest coupling coordination degree(0.82), while Hunan Province lagged relatively behind(0.74).② The driving factors exhibited spatiotemporal heterogeneity. The level of digital economy and industrial structure upgrading served as a positive driving factor, while the contribution of technological investment was not significant. Government intervention exerted a certain inhibitory effect due to the conflict between administrative governance and marketization.③ The high consistency between the actual and predicted values in 2023 confirmed the reliability of the future trend prediction. It was projected that by 2030, the coupling coordination degree of core cities such as Wuhan, Changsha, and Nanchang would approach or exceed 0.85. However, the growth rate of small and medium-sized cities would be slow, and inter-provincial disparities would narrow. [Conclusion] From 2003 to 2023, the coupling and coordinated development level of carbon reduction, pollution reduction, green expansion, and economic growth in the region has been continuously increasing and is expected to maintain an upward trend. Significant inter-provincial and intra-provincial differences are observed in development levels within the region. It is recommended to strengthen the radiating role of core cities, promote industrial transformation and the application of scientific and technological achievements, improve the ecological compensation mechanisms, and implement targeted policies based on the spatiotemporal differences of driving factors to facilitate regional coordinated development.
2026,46(2):295-305
, DOI: 10.13961/j.cnki.stbctb.2026.02.012
Abstract:
[Objective] The spatiotemporal evolution characteristics of regional land use and carbon storage were analyzed,in order to predict future changes in land use and carbon storage,thereby provide a scientific basis for achieving the 'dual carbon' goals and sustainable development.[Methods] Taking Pingxiang City as a case study,this study analyzed the spatiotemporal evolution characteristics of land use and carbon storage,explored the impact of land use change on carbon storage,and identified areas requiring protection and restoration through hot and cold spot analysis. Subsequently,the PLUS model was used to predict land use and carbon storage under different scenarios in 2035.[Results] ① From 2010 to 2024,the expansion of cultivated land and artificial surfaces encroached on forests with higher carbon density,leading to a reduction of carbon storage of 2.29×106 t. ② Two areas with relatively high hot spot intensity in the central-southern region were fragmented. Measures should be taken to make them more concentrated to improve carbon sequestration efficiency. ③ Among the predictions under the natural development, cultivated land protection, ecological protection, and urban development scenarios,carbon storage under the ecological protection scenario decreased by only 0.24%,while the other three scenarios showed significant reductions due to newly scattered artificial surfaces within forests in the central-southern region.[Conclusion] In Pingxiang City,the expansion of artificial surfaces and cultivated land leads to a reduction in forests and a decline in carbon storage. Therefore,it is necessary to protect forests in the central-southern region,optimize the layout of artificial surfaces,and minimize carbon loss under the ecological protection scenario.
[Objective] The spatiotemporal evolution characteristics of regional land use and carbon storage were analyzed,in order to predict future changes in land use and carbon storage,thereby provide a scientific basis for achieving the 'dual carbon' goals and sustainable development.[Methods] Taking Pingxiang City as a case study,this study analyzed the spatiotemporal evolution characteristics of land use and carbon storage,explored the impact of land use change on carbon storage,and identified areas requiring protection and restoration through hot and cold spot analysis. Subsequently,the PLUS model was used to predict land use and carbon storage under different scenarios in 2035.[Results] ① From 2010 to 2024,the expansion of cultivated land and artificial surfaces encroached on forests with higher carbon density,leading to a reduction of carbon storage of 2.29×106 t. ② Two areas with relatively high hot spot intensity in the central-southern region were fragmented. Measures should be taken to make them more concentrated to improve carbon sequestration efficiency. ③ Among the predictions under the natural development, cultivated land protection, ecological protection, and urban development scenarios,carbon storage under the ecological protection scenario decreased by only 0.24%,while the other three scenarios showed significant reductions due to newly scattered artificial surfaces within forests in the central-southern region.[Conclusion] In Pingxiang City,the expansion of artificial surfaces and cultivated land leads to a reduction in forests and a decline in carbon storage. Therefore,it is necessary to protect forests in the central-southern region,optimize the layout of artificial surfaces,and minimize carbon loss under the ecological protection scenario.
2026,46(2):318-329,339
, DOI: 10.13961/j.cnki.stbctb.2026.02.003
Abstract:
[Objective] The value conversion of agricultural ecological products empowered by the digital economy was explored in order to provide a theoretical basis for building digital villages and increasing farmers' income. [Methods] The ecological value of agricultural ecological products was calculated using the functional value method, and the value conversion efficiency of agricultural ecological products in 99 cities along the Yangtze River economic belt from 2012 to 2022 was measured using the super-efficiency SBM model. The variation trend of value conversion efficiency was analyzed through kernel density analysis. The impact mechanisms of the digital economy on the value conversion efficiency of agricultural ecological products were explored using the two-way fixed effects model. Furthermore, the spatial Durbin model was used to test whether there were spatial spillover effects of the digital economy on the value conversion efficiency of agricultural ecological products in the Yangtze River economic belt. [Results] ① The value conversion efficiency of agricultural ecological products in the Yangtze River economic belt showed an upward trend, with slight polarization observed.② The digital economy significantly enhanced the value conversion efficiency of agricultural ecological products.③ The digital economy improved the efficiency by promoting green technology innovation and green finance. Heterogeneity analysis indicated that in the lower reaches of the Yangtze River economic belt and in resource-based cities, the digital economy was more conducive to improving the efficiency of agricultural ecological product value conversion.④ The digital economy had a significant spatial spillover effect on the value conversion efficiency of agricultural ecological products. [Conclusion] The digital economy significantly promotes the value conversion efficiency of agricultural ecological products, exhibiting mediation effects, heterogeneity, and spatial spillover effects, which should be fully considered when promoting the conversion of agricultural ecological product value.
[Objective] The value conversion of agricultural ecological products empowered by the digital economy was explored in order to provide a theoretical basis for building digital villages and increasing farmers' income. [Methods] The ecological value of agricultural ecological products was calculated using the functional value method, and the value conversion efficiency of agricultural ecological products in 99 cities along the Yangtze River economic belt from 2012 to 2022 was measured using the super-efficiency SBM model. The variation trend of value conversion efficiency was analyzed through kernel density analysis. The impact mechanisms of the digital economy on the value conversion efficiency of agricultural ecological products were explored using the two-way fixed effects model. Furthermore, the spatial Durbin model was used to test whether there were spatial spillover effects of the digital economy on the value conversion efficiency of agricultural ecological products in the Yangtze River economic belt. [Results] ① The value conversion efficiency of agricultural ecological products in the Yangtze River economic belt showed an upward trend, with slight polarization observed.② The digital economy significantly enhanced the value conversion efficiency of agricultural ecological products.③ The digital economy improved the efficiency by promoting green technology innovation and green finance. Heterogeneity analysis indicated that in the lower reaches of the Yangtze River economic belt and in resource-based cities, the digital economy was more conducive to improving the efficiency of agricultural ecological product value conversion.④ The digital economy had a significant spatial spillover effect on the value conversion efficiency of agricultural ecological products. [Conclusion] The digital economy significantly promotes the value conversion efficiency of agricultural ecological products, exhibiting mediation effects, heterogeneity, and spatial spillover effects, which should be fully considered when promoting the conversion of agricultural ecological product value.
2026,46(2):340-352,404
, DOI: 10.13961/j.cnki.stbctb.2026.02.035
Abstract:
[Objective] The spatiotemporal differentiation patterns of ecosystem service value(ESV) in typical estuarine deltas of coastal regions in China(hereinafter referred to as the Pearl River delta, Yangtze River delta, and Yellow River delta) were systematically analyzed, in order to provide a scientific basis for the formulation of regional coordinated development and ecological conservation strategies. [Methods] By comprehensively utilizing multi-source spatiotemporal data and combining spatial analysis with econometric modeling methods, this study investigated the spatiotemporal evolution characteristics of ESV in typical estuarine deltas in 1985—2024. [Results] ① During the study period, the urbanization levels of all regions continuously increased, but the spatial patterns showed significant differences. The Pearl River delta presented a ‘core-subcenter' clustered structure, the Yangtze River delta showed a ‘metropolitan area + development axis' pattern, and the Yellow River delta exhibited a dispersed, point-like development pattern.② The spatial distribution characteristics of ESV differed substantially among regions. The Pearl River delta showed high-value clustering in the southwest, the Yangtze River delta exhibited a pronounced south-north gradient differentiation, and the Yellow River delta formed a concentric structure characterized by low values in the center and high values in the periphery.③ The spatial correlation between urbanization and ESV showed regional differences. The Pearl River delta and Yangtze River delta demonstrated a significant positive spatial correlation, whereas the Yellow River delta showed a negative correlation, revealing the differences in human-environment relationships at different stages of development. [Conclusion] In response to the demands for high-quality development and ecosystem service enhancement in typical estuarine deltas, differentiated development pathways should be adopted. The Pearl River delta should strengthen coordinated spatial governance, the Yangtze River delta should enhance integrated ecosystem management, and the Yellow River delta should establish mechanisms for realizing ecological value oriented towards resource development and climate adaptation.
[Objective] The spatiotemporal differentiation patterns of ecosystem service value(ESV) in typical estuarine deltas of coastal regions in China(hereinafter referred to as the Pearl River delta, Yangtze River delta, and Yellow River delta) were systematically analyzed, in order to provide a scientific basis for the formulation of regional coordinated development and ecological conservation strategies. [Methods] By comprehensively utilizing multi-source spatiotemporal data and combining spatial analysis with econometric modeling methods, this study investigated the spatiotemporal evolution characteristics of ESV in typical estuarine deltas in 1985—2024. [Results] ① During the study period, the urbanization levels of all regions continuously increased, but the spatial patterns showed significant differences. The Pearl River delta presented a ‘core-subcenter' clustered structure, the Yangtze River delta showed a ‘metropolitan area + development axis' pattern, and the Yellow River delta exhibited a dispersed, point-like development pattern.② The spatial distribution characteristics of ESV differed substantially among regions. The Pearl River delta showed high-value clustering in the southwest, the Yangtze River delta exhibited a pronounced south-north gradient differentiation, and the Yellow River delta formed a concentric structure characterized by low values in the center and high values in the periphery.③ The spatial correlation between urbanization and ESV showed regional differences. The Pearl River delta and Yangtze River delta demonstrated a significant positive spatial correlation, whereas the Yellow River delta showed a negative correlation, revealing the differences in human-environment relationships at different stages of development. [Conclusion] In response to the demands for high-quality development and ecosystem service enhancement in typical estuarine deltas, differentiated development pathways should be adopted. The Pearl River delta should strengthen coordinated spatial governance, the Yangtze River delta should enhance integrated ecosystem management, and the Yellow River delta should establish mechanisms for realizing ecological value oriented towards resource development and climate adaptation.
2026,46(2):353-365
, DOI: 10.13961/j.cnki.stbctb.2026.02.033
Abstract:
[Objective] The spatiotemporal variation characteristics of water ecosystem services in the Haihe River basin were analyzed, and the impact patterns of climate, land use change, and water ecological governance measures on water ecosystem services were explored, in order to provide a scientific basis for the healthy management of water resources in the river basin. [Methods] Water yield and water purification were selected as the core water ecosystem services in the Haihe River basin. Using the InVEST model, the water yield and water purification functions were simulated for nine periods from 1985 to 2023 in the river basin. Scenario analysis was applied to calculate the contribution rates of climate and land use to changes in water ecosystem services, and the GTWR model was used to quantify the impacts of climate, land use, and water ecological governance factors on water ecosystem services. [Results] ① From 1985 to 2023, water yield exhibited an overall fluctuating upward trend, with a multi-year average of 105 mm. Spatially, water yield increased in the central and southwestern regions and decreased in other regions.② From 1985 to 2023, the total nitrogen(TN) export, representing the water purification function, showed a fluctuating upward trend, while the total phosphorus(TP) export declined continuously and then stabilized. Spatially, N and P exports increased in the southern region and decreased in the northern region.③ The contribution rates of climate and land use to changes in water yield were 56% and 44%, respectively. Increases in inter-basin water transfer volume, precipitation, and water area enhanced water yield, while increases in temperature and evaporation inhibited it. The contribution rate of climate to changes in both N and P exports was 61%, and that of land use was 39%. Increases in wastewater treatment and reuse volume, evaporation, and water area promoted the water purification function, while increases in temperature and precipitation inhibited it. [Conclusion] The spatiotemporal heterogeneity of water ecosystem services in the Haihe River basin is jointly driven by climate, land use, and water ecological governance measures. High-intensity human development activities have increased water resource utilization intensity and simultaneously caused degradation of the water purification function, while water ecological governance measures have effectively alleviated this trend.
[Objective] The spatiotemporal variation characteristics of water ecosystem services in the Haihe River basin were analyzed, and the impact patterns of climate, land use change, and water ecological governance measures on water ecosystem services were explored, in order to provide a scientific basis for the healthy management of water resources in the river basin. [Methods] Water yield and water purification were selected as the core water ecosystem services in the Haihe River basin. Using the InVEST model, the water yield and water purification functions were simulated for nine periods from 1985 to 2023 in the river basin. Scenario analysis was applied to calculate the contribution rates of climate and land use to changes in water ecosystem services, and the GTWR model was used to quantify the impacts of climate, land use, and water ecological governance factors on water ecosystem services. [Results] ① From 1985 to 2023, water yield exhibited an overall fluctuating upward trend, with a multi-year average of 105 mm. Spatially, water yield increased in the central and southwestern regions and decreased in other regions.② From 1985 to 2023, the total nitrogen(TN) export, representing the water purification function, showed a fluctuating upward trend, while the total phosphorus(TP) export declined continuously and then stabilized. Spatially, N and P exports increased in the southern region and decreased in the northern region.③ The contribution rates of climate and land use to changes in water yield were 56% and 44%, respectively. Increases in inter-basin water transfer volume, precipitation, and water area enhanced water yield, while increases in temperature and evaporation inhibited it. The contribution rate of climate to changes in both N and P exports was 61%, and that of land use was 39%. Increases in wastewater treatment and reuse volume, evaporation, and water area promoted the water purification function, while increases in temperature and precipitation inhibited it. [Conclusion] The spatiotemporal heterogeneity of water ecosystem services in the Haihe River basin is jointly driven by climate, land use, and water ecological governance measures. High-intensity human development activities have increased water resource utilization intensity and simultaneously caused degradation of the water purification function, while water ecological governance measures have effectively alleviated this trend.
2026,46(2):389-404
, DOI: 10.13961/j.cnki.stbctb.2026.02.014
Abstract:
[Objective] The evolution characteristics and driving factors of water-related ecosystem services(WRESs) in Hebei Province under land use and land cover change(LUCC) and climate change(CC) scenarios in the future were quantitatively evaluated, and their multiscale uncertainties were revealed, in order to provide a scientific basis for regional water ecosystem management. [Methods] This study integrated the MRI-ESM2-0 climate model, the future land use simulation(FLUS) model, and the integrated valuation of ecosystem services and tradeoffs(InVEST) model to evaluate the integrated effects of CC and LUCC on water conservation(WC) and soil erosion(SE) in Hebei Province, and to reveal their multiscale uncertainties. [Results] From 2024 to 2050, WC in Hebei Province showed an overall upward trend under both climate scenarios. Under the SSP245 scenario, WC increased first and then stabilized, while it continuously increased under SSP585. SE exhibited an overall declining trend, decreasing steadily under SSP245 but first increasing and then decreasing under SSP585. CC played a dominant role in influencing WRESs, with its contributions to WC and SE reaching up to 99.30% and 93.14%, respectively. However, its influence gradually weakened over time. The contribution of LUCC to WC declined over time, while its contribution to SE, though smaller, gradually increased. Uncertainty driven by CC was generally higher than that driven by LUCC, and overall uncertainty decreased over time across all scales. [Conclusion] Water-related ecosystem services in Hebei Province are projected to show an overall trend of “enhanced water conservation and reduced soil erosion”. The synergistic effects of climate humidification and ecological protection significantly improve regional hydrological regulation and ecological stability. Strengthening ecological restoration and implementing zonal management are key pathways to enhance regional water security and mitigate climate risks.
[Objective] The evolution characteristics and driving factors of water-related ecosystem services(WRESs) in Hebei Province under land use and land cover change(LUCC) and climate change(CC) scenarios in the future were quantitatively evaluated, and their multiscale uncertainties were revealed, in order to provide a scientific basis for regional water ecosystem management. [Methods] This study integrated the MRI-ESM2-0 climate model, the future land use simulation(FLUS) model, and the integrated valuation of ecosystem services and tradeoffs(InVEST) model to evaluate the integrated effects of CC and LUCC on water conservation(WC) and soil erosion(SE) in Hebei Province, and to reveal their multiscale uncertainties. [Results] From 2024 to 2050, WC in Hebei Province showed an overall upward trend under both climate scenarios. Under the SSP245 scenario, WC increased first and then stabilized, while it continuously increased under SSP585. SE exhibited an overall declining trend, decreasing steadily under SSP245 but first increasing and then decreasing under SSP585. CC played a dominant role in influencing WRESs, with its contributions to WC and SE reaching up to 99.30% and 93.14%, respectively. However, its influence gradually weakened over time. The contribution of LUCC to WC declined over time, while its contribution to SE, though smaller, gradually increased. Uncertainty driven by CC was generally higher than that driven by LUCC, and overall uncertainty decreased over time across all scales. [Conclusion] Water-related ecosystem services in Hebei Province are projected to show an overall trend of “enhanced water conservation and reduced soil erosion”. The synergistic effects of climate humidification and ecological protection significantly improve regional hydrological regulation and ecological stability. Strengthening ecological restoration and implementing zonal management are key pathways to enhance regional water security and mitigate climate risks.
2026,46(2):405-416
, DOI: 10.13961/j.cnki.stbctb.2026.02.040
Abstract:
[Objective] The spatiotemporal evolution and scale-dependent driving mechanisms of newly cultivated land（NCL） in western Jilin Province were analyzed, and cultivated land protection zones were delineated, in order to provide a scientific basis for spatially differentiated cultivated land reclamation and precise management. [Methods] Based on land use data from six periods between 2000 and 2024, methods including spatial autocorrelation analysis, geodetector, and self-organizing feature map（SOFM） clustering were used to systematically examine the multi-scale driving mechanisms of NCL and to delineate cultivated land development and protection zones. [Results] ① The total cultivated land area showed a pattern of “decrease followed by an increase”. NCL increased steadily after 2010, reaching 3.51×106 hm2 by 2023. Spatially, NCL was highly clustered（global Moran's I: 0.293—0.415）.② The driving factors exhibited significant scale effects. Reserve cultivated land availability was the dominant factor at the county level（q= 0.618）, while settlement accessibility and water resource conditions were more influential at the township and village levels. At the 5 km grid scale, landscape pattern factors became the core drivers.③ Significant interactive effects were identified between socioeconomic factors such as population density and cultivated land condition factors.④ Four distinct functional zones were delineated: ecologically constrained and vulnerable zones mainly in the east and northwest, where natural constraints strongly limited the potential of NCL; cultivated land priority protection zones in areas with convenient transportation and stable cultivated land use, where strengthened protection of basic cultivated land was required; cultivated land potential development zones with abundant reserve cultivated land resources suitable for reclamation and expansion; and NCL key control zones primarily in urban-rural fringes, where strict land development control and ecological protection policies were necessary. [Conclusion] NCL in western Jilin Province is concentrated in cultivated land-dense areas in the western and southwestern parts of the study area. The driving mechanisms exhibit pronounced scale effects, and the interactions between socioeconomic and cultivated land condition factors are significant. Therefore, differentiated management measures should be implemented to optimize the layout of NCL and coordinate food security with ecological protection.
[Objective] The spatiotemporal evolution and scale-dependent driving mechanisms of newly cultivated land（NCL） in western Jilin Province were analyzed, and cultivated land protection zones were delineated, in order to provide a scientific basis for spatially differentiated cultivated land reclamation and precise management. [Methods] Based on land use data from six periods between 2000 and 2024, methods including spatial autocorrelation analysis, geodetector, and self-organizing feature map（SOFM） clustering were used to systematically examine the multi-scale driving mechanisms of NCL and to delineate cultivated land development and protection zones. [Results] ① The total cultivated land area showed a pattern of “decrease followed by an increase”. NCL increased steadily after 2010, reaching 3.51×106 hm2 by 2023. Spatially, NCL was highly clustered（global Moran's I: 0.293—0.415）.② The driving factors exhibited significant scale effects. Reserve cultivated land availability was the dominant factor at the county level（q= 0.618）, while settlement accessibility and water resource conditions were more influential at the township and village levels. At the 5 km grid scale, landscape pattern factors became the core drivers.③ Significant interactive effects were identified between socioeconomic factors such as population density and cultivated land condition factors.④ Four distinct functional zones were delineated: ecologically constrained and vulnerable zones mainly in the east and northwest, where natural constraints strongly limited the potential of NCL; cultivated land priority protection zones in areas with convenient transportation and stable cultivated land use, where strengthened protection of basic cultivated land was required; cultivated land potential development zones with abundant reserve cultivated land resources suitable for reclamation and expansion; and NCL key control zones primarily in urban-rural fringes, where strict land development control and ecological protection policies were necessary. [Conclusion] NCL in western Jilin Province is concentrated in cultivated land-dense areas in the western and southwestern parts of the study area. The driving mechanisms exhibit pronounced scale effects, and the interactions between socioeconomic and cultivated land condition factors are significant. Therefore, differentiated management measures should be implemented to optimize the layout of NCL and coordinate food security with ecological protection.
2026,46(2):417-429
, DOI: 10.13961/j.cnki.stbctb.2026.02.019
Abstract:
[Objective] The spatiotemporal variation characteristics and driving mechanisms of net ecosystem productivity（NEP） were investigated in order to provide a scientific basis for the refined evaluation of regional carbon budgets and the optimization of ecological and environmental management strategies. [Methods] Xuzhou City, a resource-exhausted city in Jiangsu Province, was selected as the study area. By integrating MOD17 A3 remote sensing products with meteorological observation data, and applying Theil-Sen median regression analysis, coefficient of variation, Hurst index, and optimal parameters-based geodetector methods, the spatiotemporal evolution patterns, fluctuation characteristics, future trends, and driving factors of vegetation NEP in Xuzhou from 2001 to 2023 were quantitatively analyzed. [Results] ① The multi-year mean NEP in Xuzhou was 141.36 g/（m2·a）(calculated as C), showing a statistically significant upward trend with an annual increase of 1.690 g/（m2·a）. Spatially, NEP exhibited a clear gradient pattern, with higher values in the northwest and southeast and lower values in the central region, forming a pronounced southeastward-increasing distribution.② From 2001 to 2023, NEP increased in 67.70% of the study area, while 13.49% experienced a decline. Highvolatility regions covered a much larger area than low-volatility regions, indicating relatively low NEP stability during the city's transition.③ Hurst exponent analysis（mean value: 0.425） indicated a tendency for future NEP trends to reverse compared with those observed over the past 23 years.④ Optimal parameters-based geodetector results identified the main driving factors of NEP variation in Xuzhou, ranked by explanatory power, as vegetation cover, environmental pollution, soil and water conservation capacity, socioeconomic development, and human activity intensity. Climate factors（temperature and precipitation） and landscape patterns played secondary roles. [Conclusion] Although Xuzhou has gradually enhanced its carbon sink capacity during the transition period, its overall stability remains limited, and there is a potential risk of future functional reversal. To maintain and strengthen regional carbon sink capacity, it is necessary to optimize vegetation restoration pathways, improve pollution control, and achieve a balanced integration of socioeconomic development and ecological protection.
[Objective] The spatiotemporal variation characteristics and driving mechanisms of net ecosystem productivity（NEP） were investigated in order to provide a scientific basis for the refined evaluation of regional carbon budgets and the optimization of ecological and environmental management strategies. [Methods] Xuzhou City, a resource-exhausted city in Jiangsu Province, was selected as the study area. By integrating MOD17 A3 remote sensing products with meteorological observation data, and applying Theil-Sen median regression analysis, coefficient of variation, Hurst index, and optimal parameters-based geodetector methods, the spatiotemporal evolution patterns, fluctuation characteristics, future trends, and driving factors of vegetation NEP in Xuzhou from 2001 to 2023 were quantitatively analyzed. [Results] ① The multi-year mean NEP in Xuzhou was 141.36 g/（m2·a）(calculated as C), showing a statistically significant upward trend with an annual increase of 1.690 g/（m2·a）. Spatially, NEP exhibited a clear gradient pattern, with higher values in the northwest and southeast and lower values in the central region, forming a pronounced southeastward-increasing distribution.② From 2001 to 2023, NEP increased in 67.70% of the study area, while 13.49% experienced a decline. Highvolatility regions covered a much larger area than low-volatility regions, indicating relatively low NEP stability during the city's transition.③ Hurst exponent analysis（mean value: 0.425） indicated a tendency for future NEP trends to reverse compared with those observed over the past 23 years.④ Optimal parameters-based geodetector results identified the main driving factors of NEP variation in Xuzhou, ranked by explanatory power, as vegetation cover, environmental pollution, soil and water conservation capacity, socioeconomic development, and human activity intensity. Climate factors（temperature and precipitation） and landscape patterns played secondary roles. [Conclusion] Although Xuzhou has gradually enhanced its carbon sink capacity during the transition period, its overall stability remains limited, and there is a potential risk of future functional reversal. To maintain and strengthen regional carbon sink capacity, it is necessary to optimize vegetation restoration pathways, improve pollution control, and achieve a balanced integration of socioeconomic development and ecological protection.
2026,46(2):430-440
, DOI: 10.13961/j.cnki.stbctb.2026.02.028
Abstract:
[Objective] The current research status and development trends in the field of plant diversity in desertified areas were analyzed, and the evolution of research hotspots and future directions were clarified, in order to provide a theoretical basis for understanding ecosystem responses, guiding ecological restoration, and informing global desertification control. [Methods] Using CiteSpace 6.4 R1, a multi-dimensional analysis is conducted on literature from CNKI(1961—2024, 1 397 articles) and Web of Science(1999—2024, 2 899 articles) databases. [Results] ① Research on plant diversity in desertified areas showed phased growth. The average annual growth rate of Chinese literature was 8.7%, with core journals represented by the Journal of Ecology, while English literature is widely distributed in interdisciplinary journals such as Frontiers in Microbiology.② Cross-regional research networks were formed by institutions including the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, and the University of California System. Chinese scholars focued on desert ecosystem structure and functional responses, while international research emphasized microbial interactions and genetic diversity.③ Keyword evolution showed that research hotspots had shifted from drought physiology(before 2000) to water-community coupling mechanisms(2000—2010), and had expanded to ecological resilience assessment and the integration of multi-omics technologies since 2020.④ The analysis of emergent words revealed that Chinese literature focused on the dynamic regulation of environmental factors, while English literature concentrated on the ecological stoichiometry of carbon, nitrogen, and phosphorus, as well as abiotic stress mechanisms. [Conclusion] This study provides a direct species resource base, mechanistic knowledge, and technical support for global desertification control. Future research should integrate multi-scale data models and cross-border monitoring networks to deepen the understanding of ‘plant-microbe-environment' interactions, thereby providing more accurate support for ecological barrier construction and the restoration of degraded ecosystems.
[Objective] The current research status and development trends in the field of plant diversity in desertified areas were analyzed, and the evolution of research hotspots and future directions were clarified, in order to provide a theoretical basis for understanding ecosystem responses, guiding ecological restoration, and informing global desertification control. [Methods] Using CiteSpace 6.4 R1, a multi-dimensional analysis is conducted on literature from CNKI(1961—2024, 1 397 articles) and Web of Science(1999—2024, 2 899 articles) databases. [Results] ① Research on plant diversity in desertified areas showed phased growth. The average annual growth rate of Chinese literature was 8.7%, with core journals represented by the Journal of Ecology, while English literature is widely distributed in interdisciplinary journals such as Frontiers in Microbiology.② Cross-regional research networks were formed by institutions including the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, and the University of California System. Chinese scholars focued on desert ecosystem structure and functional responses, while international research emphasized microbial interactions and genetic diversity.③ Keyword evolution showed that research hotspots had shifted from drought physiology(before 2000) to water-community coupling mechanisms(2000—2010), and had expanded to ecological resilience assessment and the integration of multi-omics technologies since 2020.④ The analysis of emergent words revealed that Chinese literature focused on the dynamic regulation of environmental factors, while English literature concentrated on the ecological stoichiometry of carbon, nitrogen, and phosphorus, as well as abiotic stress mechanisms. [Conclusion] This study provides a direct species resource base, mechanistic knowledge, and technical support for global desertification control. Future research should integrate multi-scale data models and cross-border monitoring networks to deepen the understanding of ‘plant-microbe-environment' interactions, thereby providing more accurate support for ecological barrier construction and the restoration of degraded ecosystems.
Zhang Shaohua, Zhao Xinxin, Yang Kai, Peng Weikang, Yang Chao, Zhang Yuxin, Zhao Zuoping, Wen Guang, Chi Zeyong
2026,46(2):441-452
, DOI: 10.13961/j.cnki.stbctb.2026.02.022
Abstract:
[Objective] The progress on microbial-biochar interaction mechanisms in saline-alkali soil improvement was systematically reviewed, in order to elucidate the mechanisms of synergistic effects, and identify potential risks, and provide a theoretical basis for the systematic development and risk management of this technology. [Methods] Using the bibliometric method, this study systematically reviews the research progress and development trends in the synergistic improvement of saline-alkali soil using microorganisms and biochar. It focuses on analyzing their synergistic mechanisms in physical structure construction, chemical environment regulation, and biological function enhancement. Furthermore, potential risks in the ‘material-strain-environmentmanagement' synergistic regulation, such as salt input and microbial competition, are discussed. [Results] This combined approach provides physical shelter and electron transfer channels through biochar, along with microbialmediated salt transformation and metabolic feedback, thereby synergistically enhancing soil functions. It can significantly reduce the electrical conductivity of saline-alkali soil, increase crop yield, and enhance the abundance of functional genes associated with the nitrogen cycle. [Conclusion] The microbial-biochar combined technology is a green and sustainable strategy for saline-alkali land management. Its synergistic mechanisms involve multidimensional physical, chemical, and biological effects, demonstrating promising application potential in both laboratory and field experiments. Future efforts should continue to focus on combination optimization, mechanism elucidation, regional adaptation, and technology integration to promote the standardized and large-scale application of this technology.
[Objective] The progress on microbial-biochar interaction mechanisms in saline-alkali soil improvement was systematically reviewed, in order to elucidate the mechanisms of synergistic effects, and identify potential risks, and provide a theoretical basis for the systematic development and risk management of this technology. [Methods] Using the bibliometric method, this study systematically reviews the research progress and development trends in the synergistic improvement of saline-alkali soil using microorganisms and biochar. It focuses on analyzing their synergistic mechanisms in physical structure construction, chemical environment regulation, and biological function enhancement. Furthermore, potential risks in the ‘material-strain-environmentmanagement' synergistic regulation, such as salt input and microbial competition, are discussed. [Results] This combined approach provides physical shelter and electron transfer channels through biochar, along with microbialmediated salt transformation and metabolic feedback, thereby synergistically enhancing soil functions. It can significantly reduce the electrical conductivity of saline-alkali soil, increase crop yield, and enhance the abundance of functional genes associated with the nitrogen cycle. [Conclusion] The microbial-biochar combined technology is a green and sustainable strategy for saline-alkali land management. Its synergistic mechanisms involve multidimensional physical, chemical, and biological effects, demonstrating promising application potential in both laboratory and field experiments. Future efforts should continue to focus on combination optimization, mechanism elucidation, regional adaptation, and technology integration to promote the standardized and large-scale application of this technology.
Mo Jiawei, Chen Fangfang, Tang Yuanyuan, Wang Kaihua, Zou Pu, Peng Yi, Xiong Zhonghua, Zhang Hanfeng
2026,46(2):453-464
, DOI: 10.13961/j.cnki.stbctb.2026.02.004
Abstract:
[Objective] The research progress on the ecological environment of key lakes in the Yangtze River economic belt was systematically reviewed. Using bibliometric methods, research hotspots, development trajectories, and frontier trends were identified in order to provide scientific references for subsequent research and policymaking. [Methods] Based on the core databases of the China National Knowledge Infrastructure(CNKI) and the Web of Science(WOS), this study retrieved Chinese and English publications related to the ecological environment of key lakes in the Yangtze River economic belt from 1979 to the present. A total of 5 081 Chinese and 2 243 English publications are included. CiteSpace 6.3. R1 software was used to conduct keyword co-occurrence analysis, cluster analysis, burst word detection, and timeline mapping. A multidimensional visualization analysis is carried out, focusing on annual publication volume, research hotspots, and evolutionary trends. [Results] ① The annual publication volume can be divided into four stages: initial(1979—1995, with an average of fewer than 50 publications per year), slow growth(1996—2003), rapid growth(2004—2015), and enhanced international influence(2016 to present). National policies and major environmental events(such as the Taihu Lake cyanobacterial bloom event) have significantly affected the research trajectory.② Research hotspots focus on five major themes: mechanisms and control of lake eutrophication; characteristics and risk assessment of water and sediment pollution; driving effects of climate change and human activities on lake ecology; ecological restoration and biodiversity conservation; and application of remote sensing and intelligent monitoring technologies.③ Research frontiers have gradually shifted from early localized pollution control to multidimensional and systematic research. This shift is particularly evident in strong burst words in recent years, including ‘climate change'(2022 to present), ‘landscape pattern'(2015 to present), and ‘ecosystem services'(2019—2021), reflecting a growing focus on the synergy of social-ecological system and the integrated relationship between rivers and lakes. [Conclusion] Research on the ecological environment of lakes in the Yangtze River economic belt has formed a complete research chain, from problem identification to driver analysis, and to governance response, establishing a distinct theoretical and practical framework. Future efforts should focus on further strengthening the research on multiscale coupling mechanisms, cross-regional ecological compensation, and coordinated optimization of land use control mechanisms for lakes, as well as deepening the application of nature-based solutions(NbS) in lake restoration, so as to support ecological protection and high-quality development of the Yangtze River economic belt.
[Objective] The research progress on the ecological environment of key lakes in the Yangtze River economic belt was systematically reviewed. Using bibliometric methods, research hotspots, development trajectories, and frontier trends were identified in order to provide scientific references for subsequent research and policymaking. [Methods] Based on the core databases of the China National Knowledge Infrastructure(CNKI) and the Web of Science(WOS), this study retrieved Chinese and English publications related to the ecological environment of key lakes in the Yangtze River economic belt from 1979 to the present. A total of 5 081 Chinese and 2 243 English publications are included. CiteSpace 6.3. R1 software was used to conduct keyword co-occurrence analysis, cluster analysis, burst word detection, and timeline mapping. A multidimensional visualization analysis is carried out, focusing on annual publication volume, research hotspots, and evolutionary trends. [Results] ① The annual publication volume can be divided into four stages: initial(1979—1995, with an average of fewer than 50 publications per year), slow growth(1996—2003), rapid growth(2004—2015), and enhanced international influence(2016 to present). National policies and major environmental events(such as the Taihu Lake cyanobacterial bloom event) have significantly affected the research trajectory.② Research hotspots focus on five major themes: mechanisms and control of lake eutrophication; characteristics and risk assessment of water and sediment pollution; driving effects of climate change and human activities on lake ecology; ecological restoration and biodiversity conservation; and application of remote sensing and intelligent monitoring technologies.③ Research frontiers have gradually shifted from early localized pollution control to multidimensional and systematic research. This shift is particularly evident in strong burst words in recent years, including ‘climate change'(2022 to present), ‘landscape pattern'(2015 to present), and ‘ecosystem services'(2019—2021), reflecting a growing focus on the synergy of social-ecological system and the integrated relationship between rivers and lakes. [Conclusion] Research on the ecological environment of lakes in the Yangtze River economic belt has formed a complete research chain, from problem identification to driver analysis, and to governance response, establishing a distinct theoretical and practical framework. Future efforts should focus on further strengthening the research on multiscale coupling mechanisms, cross-regional ecological compensation, and coordinated optimization of land use control mechanisms for lakes, as well as deepening the application of nature-based solutions(NbS) in lake restoration, so as to support ecological protection and high-quality development of the Yangtze River economic belt.
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Abstract:
[Objective] Exploring the differences in the effects of vegetation configuration of windbreak and sand-fixing forests on soil structure and nutrients in the southeastern margin of the Tengger Desert can provide a scientific reference for the selection of windbreak and sand-fixing forest configuration and the improvement of ecological environment in this area.[Method] Taking eight vegetation configurations Corethrodendron scoparium and Haloxylon ammodendron forest in single row, H.ammodendron forest with different spacing in two rows, H.ammodendron forest and H.ammodendron + H.ammodendron mixed forest ) in windbreak and sand-fixing forest as the research objects, the soil particle size characteristics and nutrient content of 0-50 cm soil layer under different vegetation configurations were studied.[Results]（1）The soil particle size of different configurations of windbreak and sand-fixing forest and grass belt in the southeastern margin of Tengger Desert is mainly fine sand ( 67.98 % ).The 8m band spacing is more conducive to the accumulation of soil fine particles, and the mixed forest configuration performs better in improving the content of fine particles and the uniformity of particle size distribution.（2）Different configurations significantly improved soil nutrient status.The 8m row spacing was 1.39 times higher than that of other soil nutrients. The soil nutrient content of Haloxylon ammodendron forest is high, the nutrient content of mixed forest is medium, and the nutrient content of Hedysarum scoparium is low.（3）Soil silt and very fine sand were significantly positively correlated with soil SOM, TN and AK ( P < 0.05 ). The mixed forest of two rows and one belt significantly enhanced the synergistic effect between soil clay, silt and total nitrogen and organic matter.[Conclusion]The broadband spacing configuration significantly increased the soil nutrient content, and the mixed forest made the soil particle distribution more concentrated. It is suggested that the mixed forest of Hedysarum scoparium + Haloxylon ammodendron with two rows and one wide band spacing ( 8 m ) should be selected as the dominant configuration in the construction of windbreak and sand-fixing forest and grass belt in Tengger Desert in the future.
[Objective] Exploring the differences in the effects of vegetation configuration of windbreak and sand-fixing forests on soil structure and nutrients in the southeastern margin of the Tengger Desert can provide a scientific reference for the selection of windbreak and sand-fixing forest configuration and the improvement of ecological environment in this area.[Method] Taking eight vegetation configurations Corethrodendron scoparium and Haloxylon ammodendron forest in single row, H.ammodendron forest with different spacing in two rows, H.ammodendron forest and H.ammodendron + H.ammodendron mixed forest ) in windbreak and sand-fixing forest as the research objects, the soil particle size characteristics and nutrient content of 0-50 cm soil layer under different vegetation configurations were studied.[Results]（1）The soil particle size of different configurations of windbreak and sand-fixing forest and grass belt in the southeastern margin of Tengger Desert is mainly fine sand ( 67.98 % ).The 8m band spacing is more conducive to the accumulation of soil fine particles, and the mixed forest configuration performs better in improving the content of fine particles and the uniformity of particle size distribution.（2）Different configurations significantly improved soil nutrient status.The 8m row spacing was 1.39 times higher than that of other soil nutrients. The soil nutrient content of Haloxylon ammodendron forest is high, the nutrient content of mixed forest is medium, and the nutrient content of Hedysarum scoparium is low.（3）Soil silt and very fine sand were significantly positively correlated with soil SOM, TN and AK ( P < 0.05 ). The mixed forest of two rows and one belt significantly enhanced the synergistic effect between soil clay, silt and total nitrogen and organic matter.[Conclusion]The broadband spacing configuration significantly increased the soil nutrient content, and the mixed forest made the soil particle distribution more concentrated. It is suggested that the mixed forest of Hedysarum scoparium + Haloxylon ammodendron with two rows and one wide band spacing ( 8 m ) should be selected as the dominant configuration in the construction of windbreak and sand-fixing forest and grass belt in Tengger Desert in the future.
Abstract:
［Objective］The characteristics of spatial heterogeneity and climate sensitivity of hydrological response changes in the Taihu Lake Basin under the influence of global warming and intense human activities were analyzed, the laws and driving mechanisms of runoff changes in the basins of reservoirs with different functions in the upper reaches of the Taihu Lake Basin were quantified, and a scientific basis was provided for ensuring the future flood control, water supply security, and ecological security in the Yangtze River Delta region.［Methods］The Shahe Reservoir Basin and Hengshan Reservoir Basin with different functional orientations in the upper reaches of the Taihu Lake Basin were taken as the research objects. A hydrological response simulation and prediction framework based on the Long Short-Term Memory (LSTM) network and Bayesian automatic optimization algorithm was constructed. Combined with historical (2006—2021) observed rainfall and discharge data, as well as future precipitation data under the CMIP6 SSP2-4.5 scenario (2022—2037, 2038—2053), the trends and causes of runoff changes in the basins of reservoirs with different functions were quantitatively analyzed.［Results］The LSTM model exhibited excellent performance in simulating daily discharge and flood events. For the Shahe Reservoir Basin, the qualification rates of flood volume, flood peak, and peak occurrence time all reached 100%; for the Hengshan Reservoir Basin, the qualification rates of flood peak and peak occurrence time were 100%, while that of flood volume was 67%. Under the interactive influence of precipitation changes and functional reservoir operation, the daily average discharge in the Shahe Reservoir Basin showed a trend of first decreasing (from 2.51 m3/s to 1.18 m3/s) and then increasing (from 1.18 m3/s to 4.66 m3/s) during 2022—2037 and 2038—2053, with a significant increase in the frequency and intensity of extreme high-flow events. In contrast, the daily average discharge in the Hengshan Reservoir Basin continued to decrease (from 3.14 m3/s to 2.29 m3/s, then to 0.83 m3/s), and the risk of extreme flood events was reduced.［Conclusion］Strengthening the construction of high-flow flood control and regulation systems for the Shahe Reservoir in the future, and focusing on improving the capacity to ensure the safety of ecological water supply under low-flow conditions for the Hengshan Reservoir, will be essential for addressing the hydrological response challenges of the two reservoirs. The research results provide scientific methods and basis for simulating hydrological responses in hilly reservoir basins and formulating differentiated response strategies under the background of climate change.
［Objective］The characteristics of spatial heterogeneity and climate sensitivity of hydrological response changes in the Taihu Lake Basin under the influence of global warming and intense human activities were analyzed, the laws and driving mechanisms of runoff changes in the basins of reservoirs with different functions in the upper reaches of the Taihu Lake Basin were quantified, and a scientific basis was provided for ensuring the future flood control, water supply security, and ecological security in the Yangtze River Delta region.［Methods］The Shahe Reservoir Basin and Hengshan Reservoir Basin with different functional orientations in the upper reaches of the Taihu Lake Basin were taken as the research objects. A hydrological response simulation and prediction framework based on the Long Short-Term Memory (LSTM) network and Bayesian automatic optimization algorithm was constructed. Combined with historical (2006—2021) observed rainfall and discharge data, as well as future precipitation data under the CMIP6 SSP2-4.5 scenario (2022—2037, 2038—2053), the trends and causes of runoff changes in the basins of reservoirs with different functions were quantitatively analyzed.［Results］The LSTM model exhibited excellent performance in simulating daily discharge and flood events. For the Shahe Reservoir Basin, the qualification rates of flood volume, flood peak, and peak occurrence time all reached 100%; for the Hengshan Reservoir Basin, the qualification rates of flood peak and peak occurrence time were 100%, while that of flood volume was 67%. Under the interactive influence of precipitation changes and functional reservoir operation, the daily average discharge in the Shahe Reservoir Basin showed a trend of first decreasing (from 2.51 m3/s to 1.18 m3/s) and then increasing (from 1.18 m3/s to 4.66 m3/s) during 2022—2037 and 2038—2053, with a significant increase in the frequency and intensity of extreme high-flow events. In contrast, the daily average discharge in the Hengshan Reservoir Basin continued to decrease (from 3.14 m3/s to 2.29 m3/s, then to 0.83 m3/s), and the risk of extreme flood events was reduced.［Conclusion］Strengthening the construction of high-flow flood control and regulation systems for the Shahe Reservoir in the future, and focusing on improving the capacity to ensure the safety of ecological water supply under low-flow conditions for the Hengshan Reservoir, will be essential for addressing the hydrological response challenges of the two reservoirs. The research results provide scientific methods and basis for simulating hydrological responses in hilly reservoir basins and formulating differentiated response strategies under the background of climate change.
Abstract:
[Objective]Erosion gully control in Northeast China"s black soil region is vital for controlling soil erosion and protecting farmland. To assess its carbon sequestration potential in soil and water conservation, optimize control measures, and enhance carbon sequestration, this study chose four representative controlled gullies as project scenarios and one similar uncontrolled gully as the baseline scenario.[Methods] Vegetation biomass was measured using the sample plot method and the harvest method. Indicators such as soil organic carbon and bulk density in the 0–20 cm and 20–40 cm soil layers were experimentally determined. The abilities of soil conservation and carbon preservation, erosion reduction and emission mitigation, soil and vegetation carbon enhancement, and straw-sealing carbon sequestration in the project scenarios were quantified to assess the accumulated carbon sequestration amount resulting from erosion gully control in the black soil region. [Results]The results show that erosion gully control contributes to soil and carbon preservation, erosion and emission reduction, soil and vegetation carbon enhancement, and straw-sealing carbon sequestration. The annual carbon sequestration amount per unit area is highest for gullies treated with straw burial (10.99 t/(hm2·a)), followed by those treated with vegetation combined with engineering measures (5.21 t/(hm2·a)), and lowest for those treated solely with vegetation measures (3.45–4.96 t/(hm2·a)). For control measures involving tree-shrub-grass combinations, trees alone, and trees combined with engineering measures, the enhancement of the vegetation carbon pool is predominant. In contrast, the straw burial treatment mode primarily enhances the soil carbon pool. The carbon sequestration effects of various erosion gully control measures are significant, indicating substantial carbon sequestration potential. It is estimated that the accumulated carbon sequestration amount per unit area can reach 1 730 774.89 t/a. [Conclusion]The research findings provide scientific support for the selection of erosion gully control modes and the assessment of carbon sequestration capacity in the future.
[Objective]Erosion gully control in Northeast China"s black soil region is vital for controlling soil erosion and protecting farmland. To assess its carbon sequestration potential in soil and water conservation, optimize control measures, and enhance carbon sequestration, this study chose four representative controlled gullies as project scenarios and one similar uncontrolled gully as the baseline scenario.[Methods] Vegetation biomass was measured using the sample plot method and the harvest method. Indicators such as soil organic carbon and bulk density in the 0–20 cm and 20–40 cm soil layers were experimentally determined. The abilities of soil conservation and carbon preservation, erosion reduction and emission mitigation, soil and vegetation carbon enhancement, and straw-sealing carbon sequestration in the project scenarios were quantified to assess the accumulated carbon sequestration amount resulting from erosion gully control in the black soil region. [Results]The results show that erosion gully control contributes to soil and carbon preservation, erosion and emission reduction, soil and vegetation carbon enhancement, and straw-sealing carbon sequestration. The annual carbon sequestration amount per unit area is highest for gullies treated with straw burial (10.99 t/(hm2·a)), followed by those treated with vegetation combined with engineering measures (5.21 t/(hm2·a)), and lowest for those treated solely with vegetation measures (3.45–4.96 t/(hm2·a)). For control measures involving tree-shrub-grass combinations, trees alone, and trees combined with engineering measures, the enhancement of the vegetation carbon pool is predominant. In contrast, the straw burial treatment mode primarily enhances the soil carbon pool. The carbon sequestration effects of various erosion gully control measures are significant, indicating substantial carbon sequestration potential. It is estimated that the accumulated carbon sequestration amount per unit area can reach 1 730 774.89 t/a. [Conclusion]The research findings provide scientific support for the selection of erosion gully control modes and the assessment of carbon sequestration capacity in the future.
Abstract:
［Objective］Artificial young forests are an important component of forest carbon sinks in Guangxi. Clarifying the dominant factors of their carbon sink function is the basis for formulating forest carbon sequestration management strategies. This study took the artificial young forests in the Liuzhou section of the Liujiang River Basin as the research object, investigated the effects of stand structure and soil site conditions on vegetation carbon density, and identified the key influencing factors.［Methods］Stand data were obtained through field plot surveys. Vegetation carbon density of five types of artificial young forests was estimated using biomass equations and carbon content coefficients. Key factors were identified using a random forest model, and Pearson correlation analysis was further applied to reveal the relationships between vegetation carbon density and each factor.［ Results］ (1) Vegetation carbon density differed significantly among forest types, with broad-leaved forests having the highest (84.58±65.72 t·hm-2) and shrublands the lowest (15.93±2.20 t·hm-2). (2) Stand structure and site conditions jointly dominated vegetation carbon density patterns. DBH was the most critical stand factor with the highest contribution rate (39.70%); soil layer thickness (25.40%), soil type, and humus layer thickness were important site factors. Vegetation carbon density increased significantly with increasing DBH and soil layer thickness (p<0.05). (3) High understory species diversity does not necessarily lead to high carbon storage.［Conclusion］Vegetation carbon density of artificial young forests in the Liujiang River Basin is primarily controlled by stand structure and site conditions, with DBH and soil layer thickness being the key factors constraining carbon accumulation. The influence of understory diversity is limited, as the biomass accumulation of a few dominant tree species dominates carbon density patterns, with the "selection effect" suppressing the "complementarity effect" of understory diversity. These results suggest that enhancing carbon sequestration in plantations of the Liuzhou section requires optimizing tree species composition, promoting DBH growth, and improving soil conditions through measures such as adjusting the proportion of broad-leaved species, timely tending and thinning, and retaining litter.
［Objective］Artificial young forests are an important component of forest carbon sinks in Guangxi. Clarifying the dominant factors of their carbon sink function is the basis for formulating forest carbon sequestration management strategies. This study took the artificial young forests in the Liuzhou section of the Liujiang River Basin as the research object, investigated the effects of stand structure and soil site conditions on vegetation carbon density, and identified the key influencing factors.［Methods］Stand data were obtained through field plot surveys. Vegetation carbon density of five types of artificial young forests was estimated using biomass equations and carbon content coefficients. Key factors were identified using a random forest model, and Pearson correlation analysis was further applied to reveal the relationships between vegetation carbon density and each factor.［ Results］ (1) Vegetation carbon density differed significantly among forest types, with broad-leaved forests having the highest (84.58±65.72 t·hm-2) and shrublands the lowest (15.93±2.20 t·hm-2). (2) Stand structure and site conditions jointly dominated vegetation carbon density patterns. DBH was the most critical stand factor with the highest contribution rate (39.70%); soil layer thickness (25.40%), soil type, and humus layer thickness were important site factors. Vegetation carbon density increased significantly with increasing DBH and soil layer thickness (p<0.05). (3) High understory species diversity does not necessarily lead to high carbon storage.［Conclusion］Vegetation carbon density of artificial young forests in the Liujiang River Basin is primarily controlled by stand structure and site conditions, with DBH and soil layer thickness being the key factors constraining carbon accumulation. The influence of understory diversity is limited, as the biomass accumulation of a few dominant tree species dominates carbon density patterns, with the "selection effect" suppressing the "complementarity effect" of understory diversity. These results suggest that enhancing carbon sequestration in plantations of the Liuzhou section requires optimizing tree species composition, promoting DBH growth, and improving soil conditions through measures such as adjusting the proportion of broad-leaved species, timely tending and thinning, and retaining litter.
Abstract:
[Objective]Clarifying the typical spatio-temporal evolution laws and coupling coordination characteristics of the productional-living-ecological functions of the main grain-producing areas' land is of great significance for ensuring national food security and promoting the healthy and sustainable development of the land space.[Methods] This study takes six major grain-producing counties along the Yellow River in Henan Province, including Yuanyang and Fengqiu, as the research area. It constructs an evaluation index system for the productional-living-ecological functions and combines the coupling coordination degree model and GIS spatial data analysis methods to explore the status and coordination characteristics of the production, living and ecological productional-living-ecological functions of the land space from 2008 to 2023,.and puts forward targeted mitigation strategies. [Rresults]①From 2008 to 2023, the average comprehensive function score of the productional-living-ecological functions in the study area increased from 0.147 in 2008 to 0.364 in 2023, with an increase of 147.62%. The evaluation scores of production and living functions were significantly higher than that of ecological function.②During the study period, the overall grade of the productional-living-ecological functions in this area significantly improved, and there was a continuous spatial differentiation feature. The functional evolution presented a gradient differentiation pattern of "high in the east and low in the west"③From 2008 to 2023, the coupling coordination degree of the productional-living-ecologica functions in this area ranged from 0.263 to 0.515. Over the 15 years, it crossed four coordination degree grades, from moderately disordered type to barely coordinated type. The differences in the interval levels between adjacent years were relatively small, and the overall situation was relatively balanced.[Conclusion] In response to the spatio-temporal differentiation and the need for improvement in the coupling coordination degree of the productional-living-ecological functions in the research area, it is necessary to optimize the spatial layout, strengthen the synergy between production and ecology, and improve the regional collaboration mechanism to promote food security and sustainable development, providing a reference basis for the coordinated development of the productional-living-ecological space in the research area and other areas along the Yellow River in Henan Province.
[Objective]Clarifying the typical spatio-temporal evolution laws and coupling coordination characteristics of the productional-living-ecological functions of the main grain-producing areas' land is of great significance for ensuring national food security and promoting the healthy and sustainable development of the land space.[Methods] This study takes six major grain-producing counties along the Yellow River in Henan Province, including Yuanyang and Fengqiu, as the research area. It constructs an evaluation index system for the productional-living-ecological functions and combines the coupling coordination degree model and GIS spatial data analysis methods to explore the status and coordination characteristics of the production, living and ecological productional-living-ecological functions of the land space from 2008 to 2023,.and puts forward targeted mitigation strategies. [Rresults]①From 2008 to 2023, the average comprehensive function score of the productional-living-ecological functions in the study area increased from 0.147 in 2008 to 0.364 in 2023, with an increase of 147.62%. The evaluation scores of production and living functions were significantly higher than that of ecological function.②During the study period, the overall grade of the productional-living-ecological functions in this area significantly improved, and there was a continuous spatial differentiation feature. The functional evolution presented a gradient differentiation pattern of "high in the east and low in the west"③From 2008 to 2023, the coupling coordination degree of the productional-living-ecologica functions in this area ranged from 0.263 to 0.515. Over the 15 years, it crossed four coordination degree grades, from moderately disordered type to barely coordinated type. The differences in the interval levels between adjacent years were relatively small, and the overall situation was relatively balanced.[Conclusion] In response to the spatio-temporal differentiation and the need for improvement in the coupling coordination degree of the productional-living-ecological functions in the research area, it is necessary to optimize the spatial layout, strengthen the synergy between production and ecology, and improve the regional collaboration mechanism to promote food security and sustainable development, providing a reference basis for the coordinated development of the productional-living-ecological space in the research area and other areas along the Yellow River in Henan Province.
Abstract:
[Objective] Agropastoral ecotones serve as crucial ecological shields and key supply areas for agricultural and livestock products, revealing the dynamics and future changes of carbon storage (CS) in these areas hold both theoretical and practical significance for achieving regional “Dual Carbon” goals and optimizing territorial spatial planning. [Methods] Taking the Tabu agropastoral ecotone in Inner Mongolia as the study area, the carbon density values were modified yearly based on precipitation and temperature. Based on long time-series land use and land cover (LULC), climatic, and socio-economic data from 2000 to 2025, the spatiotemporal dynamics and driving mechanisms of CS were analyzed by integrating the framework of PLUS–InVEST–OPGD models, and its spatial patterns under multiple scenarios in 2030 were simulated. [Results] ① From 2000 to 2025, the multi-year average CS in the study area was 834.29×106, exhibiting a fluctuating increase (P＞0.05,Cv=0.13). Spatially, CS presented a stable gradient characterized by higher levels in the south and lower levels in the north. Moderate- and low-FVC grasslands and farmland contributed up to 82.8% of the regional CS. ② LULC(q=1.00) and the enhanced vegetation index (EVI, q=0.52) were the key factors driving CS dynamics, while the explanatory power of GDP and human footprint increased over time. Interactions among factors were predominantly characterized by bivariate enhancement. ③ Based on historical development trends, CS under inertial development, socio-economic development, and production-living-ecology coordinated development scenarios in 2030 increased by 101.52×106 t, 121.97×106 t and 152.91×106 t compared with the base year (2022). [Conclusion] Medium- and low-FVC grasslands and farmland are the primary carbon pools in the agropastoral ecotone. The spatial variance of regional CS results from the coupling of multi-dimensional factors, with the influence of human activities continuously strengthening. The production-living-ecology coordinated development scenario better satisfies the dual demands of maintaining ecological shield functions and ensuring the supply of agricultural and livestock products in agropastoral ecotones.
[Objective] Agropastoral ecotones serve as crucial ecological shields and key supply areas for agricultural and livestock products, revealing the dynamics and future changes of carbon storage (CS) in these areas hold both theoretical and practical significance for achieving regional “Dual Carbon” goals and optimizing territorial spatial planning. [Methods] Taking the Tabu agropastoral ecotone in Inner Mongolia as the study area, the carbon density values were modified yearly based on precipitation and temperature. Based on long time-series land use and land cover (LULC), climatic, and socio-economic data from 2000 to 2025, the spatiotemporal dynamics and driving mechanisms of CS were analyzed by integrating the framework of PLUS–InVEST–OPGD models, and its spatial patterns under multiple scenarios in 2030 were simulated. [Results] ① From 2000 to 2025, the multi-year average CS in the study area was 834.29×106, exhibiting a fluctuating increase (P＞0.05,Cv=0.13). Spatially, CS presented a stable gradient characterized by higher levels in the south and lower levels in the north. Moderate- and low-FVC grasslands and farmland contributed up to 82.8% of the regional CS. ② LULC(q=1.00) and the enhanced vegetation index (EVI, q=0.52) were the key factors driving CS dynamics, while the explanatory power of GDP and human footprint increased over time. Interactions among factors were predominantly characterized by bivariate enhancement. ③ Based on historical development trends, CS under inertial development, socio-economic development, and production-living-ecology coordinated development scenarios in 2030 increased by 101.52×106 t, 121.97×106 t and 152.91×106 t compared with the base year (2022). [Conclusion] Medium- and low-FVC grasslands and farmland are the primary carbon pools in the agropastoral ecotone. The spatial variance of regional CS results from the coupling of multi-dimensional factors, with the influence of human activities continuously strengthening. The production-living-ecology coordinated development scenario better satisfies the dual demands of maintaining ecological shield functions and ensuring the supply of agricultural and livestock products in agropastoral ecotones.
Abstract:
Under the dual carbon goals, the digital economy has become a crucial driver promoting the green transformation of agriculture. Using panel data from 30 provinces in China from 2015 to 2023, this study explores the impact mechanism and spatial spillover effects of digital economy development on agricultural carbon emission intensity through benchmark regression models, moderating effect models, and the spatial Durbin model. The findings are as follows: (1) From 2015 to 2023, the digital economy index of China’s 30 provinces showed overall rapid growth, with the growth rate decreasing from east to west. The gap between provinces with high and low levels of digitalization continues to widen. In terms of temporal evolution, agricultural carbon emission intensity exhibited a steady downward trend overall. From a regional distribution perspective, agricultural carbon emission intensity in central and western regions is significantly higher than in eastern provinces, and gradient differences in carbon reduction levels among provinces are quite pronounced. (2) In eastern regions, the scale characteristics of agriculture lead to a more prominent positive effect of the digital economy on agricultural carbon emission intensity. In central regions, agricultural carbon emission intensity shows a declining trend. In western regions, the pace of digitalization is relatively slower compared to the other two regions, and its impact on agricultural carbon emission intensity is not significant. (3) Moderating effect analysis reveals that increased financial support for agriculture and the advancement of urbanization can indirectly curb agricultural carbon emission intensity by promoting digital development. The decomposition results of spatial spillover effects indicate that rural residents’ disposable income significantly inhibits agricultural carbon emission intensity, and this effect is fully reflected in the total effect, direct effect, and indirect effect, demonstrating both local and cross-regional transmission characteristics in its impact on agricultural carbon reduction. (4) The inhibitory effect of digital economy development on agricultural carbon emission intensity is particularly significant in eastern regions, major grain-producing areas, and crop farming zones. Therefore, the state should enhance financial support for agriculture, increase farmers’ income, and fully leverage the positive role of the digital economy in technology penetration, industrial structure adjustment, and urbanization to reduce agricultural carbon emissions. Meanwhile, when formulating differentiated carbon reduction policies, the government should clarify the core direction to ensure that the digital economy can exert its low-carbon positive externality, thereby contributing to high-quality agricultural development.
Under the dual carbon goals, the digital economy has become a crucial driver promoting the green transformation of agriculture. Using panel data from 30 provinces in China from 2015 to 2023, this study explores the impact mechanism and spatial spillover effects of digital economy development on agricultural carbon emission intensity through benchmark regression models, moderating effect models, and the spatial Durbin model. The findings are as follows: (1) From 2015 to 2023, the digital economy index of China’s 30 provinces showed overall rapid growth, with the growth rate decreasing from east to west. The gap between provinces with high and low levels of digitalization continues to widen. In terms of temporal evolution, agricultural carbon emission intensity exhibited a steady downward trend overall. From a regional distribution perspective, agricultural carbon emission intensity in central and western regions is significantly higher than in eastern provinces, and gradient differences in carbon reduction levels among provinces are quite pronounced. (2) In eastern regions, the scale characteristics of agriculture lead to a more prominent positive effect of the digital economy on agricultural carbon emission intensity. In central regions, agricultural carbon emission intensity shows a declining trend. In western regions, the pace of digitalization is relatively slower compared to the other two regions, and its impact on agricultural carbon emission intensity is not significant. (3) Moderating effect analysis reveals that increased financial support for agriculture and the advancement of urbanization can indirectly curb agricultural carbon emission intensity by promoting digital development. The decomposition results of spatial spillover effects indicate that rural residents’ disposable income significantly inhibits agricultural carbon emission intensity, and this effect is fully reflected in the total effect, direct effect, and indirect effect, demonstrating both local and cross-regional transmission characteristics in its impact on agricultural carbon reduction. (4) The inhibitory effect of digital economy development on agricultural carbon emission intensity is particularly significant in eastern regions, major grain-producing areas, and crop farming zones. Therefore, the state should enhance financial support for agriculture, increase farmers’ income, and fully leverage the positive role of the digital economy in technology penetration, industrial structure adjustment, and urbanization to reduce agricultural carbon emissions. Meanwhile, when formulating differentiated carbon reduction policies, the government should clarify the core direction to ensure that the digital economy can exert its low-carbon positive externality, thereby contributing to high-quality agricultural development.
Abstract:
To explore the effects of different planting densities of oat on the physical and chemical properties of secondary salinized farmland soil, three oat return treatment groups with low density (YMD), medium density (YMZ), and high density (YMG) were set up in a typical secondary salinized farmland in Beiwugegutu Village, Huatugula Town, Zuozhong Banner, Tongliao City, Inner Mongolia Autonomous Region. The bare land without oat planting was used as the control (CK). The oat was returned to the field when it grew to the beginning of July. Soil samples from the 0-20 cm layer were collected three days before and three months after the return of the oat, and the pH value, exchangeable sodium percentage (ESP), anion and cation composition, organic matter content, and available nitrogen, available phosphorus and available potassium were determined. The results showed that the return of oat significantly improved the physical and chemical properties of salinized soil. Among them, the high-density treatment (YMG) showed a more significant improvement effect compared with the medium-density (YMZ), low-density (YMD) and control (CK) groups. Compared with CK, the return of oat at different densities could effectively increase the soil organic matter content by nearly 5.00 g/kg. Compared with CK, YMG simultaneously reduced the soil pH value and ESP by 0.77 and 8.18%, respectively, and the effect of high-density treatment was the most obvious. The analysis of eight major ions showed that the concentrations of K?, Na?, Cl?, HCO?? and CO?2? decreased, and YMG decreased by 0.44, 0.45, 0.19, 0.19 and 0.13 g/kg respectively compared with CK; while the contents of Ca2?, Mg2? and SO?2? increased by 0.19, 0.12 and 0.18 g/kg respectively. In terms of nutrient indicators, the available nitrogen content increased by 21, 28 and 44.33 mg/kg respectively under YMD, YMZ and YMG treatments compared with CK; the available phosphorus content increased by 5.57, 7.09 and 7.45 mg/kg respectively; and the available potassium content increased by 22.61, 26.59 and 34.56 mg/kg respectively. In conclusion, planting and returning different densities of oat in secondary salinized farmland can effectively alleviate the degree of soil salinization and significantly improve the soil fertility level.
To explore the effects of different planting densities of oat on the physical and chemical properties of secondary salinized farmland soil, three oat return treatment groups with low density (YMD), medium density (YMZ), and high density (YMG) were set up in a typical secondary salinized farmland in Beiwugegutu Village, Huatugula Town, Zuozhong Banner, Tongliao City, Inner Mongolia Autonomous Region. The bare land without oat planting was used as the control (CK). The oat was returned to the field when it grew to the beginning of July. Soil samples from the 0-20 cm layer were collected three days before and three months after the return of the oat, and the pH value, exchangeable sodium percentage (ESP), anion and cation composition, organic matter content, and available nitrogen, available phosphorus and available potassium were determined. The results showed that the return of oat significantly improved the physical and chemical properties of salinized soil. Among them, the high-density treatment (YMG) showed a more significant improvement effect compared with the medium-density (YMZ), low-density (YMD) and control (CK) groups. Compared with CK, the return of oat at different densities could effectively increase the soil organic matter content by nearly 5.00 g/kg. Compared with CK, YMG simultaneously reduced the soil pH value and ESP by 0.77 and 8.18%, respectively, and the effect of high-density treatment was the most obvious. The analysis of eight major ions showed that the concentrations of K?, Na?, Cl?, HCO?? and CO?2? decreased, and YMG decreased by 0.44, 0.45, 0.19, 0.19 and 0.13 g/kg respectively compared with CK; while the contents of Ca2?, Mg2? and SO?2? increased by 0.19, 0.12 and 0.18 g/kg respectively. In terms of nutrient indicators, the available nitrogen content increased by 21, 28 and 44.33 mg/kg respectively under YMD, YMZ and YMG treatments compared with CK; the available phosphorus content increased by 5.57, 7.09 and 7.45 mg/kg respectively; and the available potassium content increased by 22.61, 26.59 and 34.56 mg/kg respectively. In conclusion, planting and returning different densities of oat in secondary salinized farmland can effectively alleviate the degree of soil salinization and significantly improve the soil fertility level.
Abstract:
Abstract: [Objective] Desertification in the six northern provinces and regions accounts for 81.5% of China's total desertified area. Investigating the sensitivity of desertification in these areas holds significant importance for ecological security and socioeconomic development in northern China. [Methods] Based on the Mediterranean Desertification and Land Use model, map analysis, and geographical detector, this study analyzed the spatiotemporal evolution characteristics and driving mechanisms of desertification sensitivity in the six northern provinces and autonomous regions during the period from 2010 to 2023. [Results] (1) Desertification sensitivity in the six northern provinces and autonomous regions was dominated by a stable type. The area of transitions among different sensitivity types reached 1.3622 million km2, accounting for 36.11% of the study area. Transitions mainly occurred among high-, medium-, and low-sensitivity types, as well as at the boundaries between different sensitivity types. (2) There are marked differences in the changes in the areas of various desertification sensitivity types. Specifically, the area of extremely sensitive regions shifted from increasing to decreasing; high-sensitivity areas fluctuated; medium-sensitivity areas decreased significantly; low-sensitivity areas continued to expand; and non-sensitive areas remained stable. Overall, these trends indicate a general alleviation of desertification sensitivity. (3) The driving factor analysis revealed that the interaction between aridity and land use type exerted the strongest influence. Among the individual driving factors, aridity had the greatest effect on changes in desertification sensitivity. [Conclusion] During the study period, the overall desertification sensitivity in the six northern provinces and autonomous regions decreased, showing a spatial distribution pattern of higher sensitivity in the west and lower sensitivity in the east. In future desertification control efforts in this region, enhanced monitoring of climatic factors and rational planning of land use types are recommended.
Abstract: [Objective] Desertification in the six northern provinces and regions accounts for 81.5% of China's total desertified area. Investigating the sensitivity of desertification in these areas holds significant importance for ecological security and socioeconomic development in northern China. [Methods] Based on the Mediterranean Desertification and Land Use model, map analysis, and geographical detector, this study analyzed the spatiotemporal evolution characteristics and driving mechanisms of desertification sensitivity in the six northern provinces and autonomous regions during the period from 2010 to 2023. [Results] (1) Desertification sensitivity in the six northern provinces and autonomous regions was dominated by a stable type. The area of transitions among different sensitivity types reached 1.3622 million km2, accounting for 36.11% of the study area. Transitions mainly occurred among high-, medium-, and low-sensitivity types, as well as at the boundaries between different sensitivity types. (2) There are marked differences in the changes in the areas of various desertification sensitivity types. Specifically, the area of extremely sensitive regions shifted from increasing to decreasing; high-sensitivity areas fluctuated; medium-sensitivity areas decreased significantly; low-sensitivity areas continued to expand; and non-sensitive areas remained stable. Overall, these trends indicate a general alleviation of desertification sensitivity. (3) The driving factor analysis revealed that the interaction between aridity and land use type exerted the strongest influence. Among the individual driving factors, aridity had the greatest effect on changes in desertification sensitivity. [Conclusion] During the study period, the overall desertification sensitivity in the six northern provinces and autonomous regions decreased, showing a spatial distribution pattern of higher sensitivity in the west and lower sensitivity in the east. In future desertification control efforts in this region, enhanced monitoring of climatic factors and rational planning of land use types are recommended.
Abstract:
[Objective] Scientifically and rationally assessing the spatiotemporal evolution and driving factors of cultivated land ecological security in the Beijing-Tianjin-Hebei region can raise the awareness of relevant authorities regarding the protection of cultivated land ecology, and provide solid theoretical support and scientific basis for accelerating the construction of a pattern of high-quality agricultural development. [Methods] Based on the Pressure-State-Response (P-S-R) framework, this study firstly establishes the evaluation index system of cultivated land ecological security level. By integrating the entropy weight method, Kernel density estimation and Dagum Gini coefficient analyze the developmental trajectory, evolution characteristics, and sources of regional disparities in cultivated land ecological security across the Beijing-Tianjin-Hebei region from 2011 to 2022. Additionally, the spatial-temporal heterogeneity of influencing factors cultivated land ecological security is explored using the Geographically and Temporally Weighted Regression (GTWR) model. [Results] The cultivated land ecological security in the Beijing-Tianjin-Hebei region has steadily improved, and the regional growth rates characterized by "central leadership followed by northern and southern regions." Among the three P-S-R dimensions, Among the three P-S-R dimensions, the pressure dimension shows a significant upward trend, while the state and response dimensions display fluctuating downward trends. The absolute differences in cultivated land ecological security levels among cities have gradually narrowed, with pronounced differentiation in the northern region and more balanced development in central and southern regions. The overall regional differences in cultivated land ecological security slightly narrowed, and the differences in the region are in the order of highest to lowest: south > central > north, primarily driven by net inter-regional differences. The influencing factors of cultivated land ecological security demonstrate significant spatial heterogeneity. Among them, crop cultivation structure, agricultural financial support, and funding for agricultural research activities demonstrate positive driving effects; natural factors (e.g. sunshine hours and precipitation) exert bidirectional effects; and per capita GDP primarily exerts inhibitory effects.
[Objective] Scientifically and rationally assessing the spatiotemporal evolution and driving factors of cultivated land ecological security in the Beijing-Tianjin-Hebei region can raise the awareness of relevant authorities regarding the protection of cultivated land ecology, and provide solid theoretical support and scientific basis for accelerating the construction of a pattern of high-quality agricultural development. [Methods] Based on the Pressure-State-Response (P-S-R) framework, this study firstly establishes the evaluation index system of cultivated land ecological security level. By integrating the entropy weight method, Kernel density estimation and Dagum Gini coefficient analyze the developmental trajectory, evolution characteristics, and sources of regional disparities in cultivated land ecological security across the Beijing-Tianjin-Hebei region from 2011 to 2022. Additionally, the spatial-temporal heterogeneity of influencing factors cultivated land ecological security is explored using the Geographically and Temporally Weighted Regression (GTWR) model. [Results] The cultivated land ecological security in the Beijing-Tianjin-Hebei region has steadily improved, and the regional growth rates characterized by "central leadership followed by northern and southern regions." Among the three P-S-R dimensions, Among the three P-S-R dimensions, the pressure dimension shows a significant upward trend, while the state and response dimensions display fluctuating downward trends. The absolute differences in cultivated land ecological security levels among cities have gradually narrowed, with pronounced differentiation in the northern region and more balanced development in central and southern regions. The overall regional differences in cultivated land ecological security slightly narrowed, and the differences in the region are in the order of highest to lowest: south > central > north, primarily driven by net inter-regional differences. The influencing factors of cultivated land ecological security demonstrate significant spatial heterogeneity. Among them, crop cultivation structure, agricultural financial support, and funding for agricultural research activities demonstrate positive driving effects; natural factors (e.g. sunshine hours and precipitation) exert bidirectional effects; and per capita GDP primarily exerts inhibitory effects.
Abstract:
Soil represents the largest organic carbon (C) pool in terrestrial ecosystems, and the regulatory mechanisms by which microbial communities influence carbon pool dynamics have emerged as a major focus in terrestrial carbon cycle research. In this study, sediments from check dams on the Ordos Plateau were analyzed to compare bacterial communities across two precipitation zones (250–300 mm and 350–400 mm), assessing their effects on the MBC/SOC and DOC/SOC ratios. Results indicated that in the 350-400 mm precipitation zone, total nitrogen(TN)and SOC contents were significantly greater than those in the 250–300 mm zone by 135.29% and 50.00%, respectively (p<0.001), whereas sand content significantly declined by 25.28% (p<0.01).In the 250-300 mm zone, Actinobacteriota (10.74%-37.16%)and Acidobacteriota (13.05%–18.61%) were predominant, with the combined relative abundance of Chloroflexota and Gemmatimonadota reaching 16.33%. In contrast, in the 350-400 mm zone, Proteobacteria was significantly enriched (24.62%-56.57%), accompanied by marked increases in Escherichia–Shigella (15.79%-25.28%) and Pseudomonas (3.35%-8.28%), leading to greater community dominance. In the low-precipitation zone, K-strategist bacteria (Actinobacteriota) dominated the community, facilitating carbon decomposition and reducing carbon stability, whereas in the high-precipitation zone, the community shifted toward r-strategist bacteria (Proteobacteria), enhancing carbon fixation functions, such as the Calvin cycle, and thereby decreasing DOC/SOC and MBC/SOC ratios. Elucidation of microbial mechanisms underlying carbon sequestration in check dam sediments within ecologically fragile areas is essential for improving terrestrial ecosystem carbon sink capacity and supporting national “carbon neutrality” strategies.
Soil represents the largest organic carbon (C) pool in terrestrial ecosystems, and the regulatory mechanisms by which microbial communities influence carbon pool dynamics have emerged as a major focus in terrestrial carbon cycle research. In this study, sediments from check dams on the Ordos Plateau were analyzed to compare bacterial communities across two precipitation zones (250–300 mm and 350–400 mm), assessing their effects on the MBC/SOC and DOC/SOC ratios. Results indicated that in the 350-400 mm precipitation zone, total nitrogen(TN)and SOC contents were significantly greater than those in the 250–300 mm zone by 135.29% and 50.00%, respectively (p<0.001), whereas sand content significantly declined by 25.28% (p<0.01).In the 250-300 mm zone, Actinobacteriota (10.74%-37.16%)and Acidobacteriota (13.05%–18.61%) were predominant, with the combined relative abundance of Chloroflexota and Gemmatimonadota reaching 16.33%. In contrast, in the 350-400 mm zone, Proteobacteria was significantly enriched (24.62%-56.57%), accompanied by marked increases in Escherichia–Shigella (15.79%-25.28%) and Pseudomonas (3.35%-8.28%), leading to greater community dominance. In the low-precipitation zone, K-strategist bacteria (Actinobacteriota) dominated the community, facilitating carbon decomposition and reducing carbon stability, whereas in the high-precipitation zone, the community shifted toward r-strategist bacteria (Proteobacteria), enhancing carbon fixation functions, such as the Calvin cycle, and thereby decreasing DOC/SOC and MBC/SOC ratios. Elucidation of microbial mechanisms underlying carbon sequestration in check dam sediments within ecologically fragile areas is essential for improving terrestrial ecosystem carbon sink capacity and supporting national “carbon neutrality” strategies.
Abstract:
Abstract: [Objective] This study investigates the water holding capacity of litter and soil across different forest types in Danxia Mountain, Guangdong Province, providing a scientific basis for forest management in the region. [Methods] Using indoor immersion methods, this study investigated the water holding characteristics of litter and understory soil across five forest types in Danxia Mountain (Sassafras tzumu, Schima superba, Pinus massoniana, Quercus phillyreoides, and Neolitsea aurata). [Results] ① The litter volume of the five forest types ranged from 13.62 - 42.86 t/ha, with the S. superba forest showing the highest value. The maximum water holding rate ranged from 59.76% to 87.93%, highest in the S. tzumu forest. The maximum water holding capacity ranged from 11.83 - 26.22 t/ha, with the S. superba forest being the largest. The maximum interception rate and effective interception rate ranged from 38.21% to 65.79% and 29.25% to 52.61%, respectively, both peaking in the S. tzumu forest. The maximum interception capacity and effective interception capacity ranged from 8.71 - 17.04 t/ha and 6.74 - 13.11 t/ha, respectively, with the S. superba forest exhibiting the highest values for both parameters. ② The water holding capacity of litter across all forest types showed a consistent trend with immersion time, exhibiting a positive correlation that followed a logarithmic function. The water absorption rate was negatively correlated with immersion time, conforming to a power function. At any given immersion time, the S. superba forest exhibited the highest litter water holding capacity and water absorption rate. ③ Soil bulk density of the different forest types ranged from 1.22 - 1.49 g/cm3, with the S. superba forest showing the highest value and the S. tzumu forest the lowest. Soil porosity ranged from 43.89% to 53.82%, exhibiting a negative correlation with bulk density. The saturation water holding capacity and maximum water holding capacity ranged from 877.74 - 1 076.30 t/ha and 591.27 - 849.80 t/ha, respectively, with both parameters being highest in the S. tzumu forest. Comprehensive evaluation indicates that the S. superba forest in the Danxia Mountain area demonstrates significant advantages in both litter and soil water holding capacity. [Conclusion] Therefore, it is recommended that priority be given to increasing the proportion of the S. superba forest in regional forest management strategies to enhance the overall water conservation and soil water holding functions of the ecosystem.
Abstract: [Objective] This study investigates the water holding capacity of litter and soil across different forest types in Danxia Mountain, Guangdong Province, providing a scientific basis for forest management in the region. [Methods] Using indoor immersion methods, this study investigated the water holding characteristics of litter and understory soil across five forest types in Danxia Mountain (Sassafras tzumu, Schima superba, Pinus massoniana, Quercus phillyreoides, and Neolitsea aurata). [Results] ① The litter volume of the five forest types ranged from 13.62 - 42.86 t/ha, with the S. superba forest showing the highest value. The maximum water holding rate ranged from 59.76% to 87.93%, highest in the S. tzumu forest. The maximum water holding capacity ranged from 11.83 - 26.22 t/ha, with the S. superba forest being the largest. The maximum interception rate and effective interception rate ranged from 38.21% to 65.79% and 29.25% to 52.61%, respectively, both peaking in the S. tzumu forest. The maximum interception capacity and effective interception capacity ranged from 8.71 - 17.04 t/ha and 6.74 - 13.11 t/ha, respectively, with the S. superba forest exhibiting the highest values for both parameters. ② The water holding capacity of litter across all forest types showed a consistent trend with immersion time, exhibiting a positive correlation that followed a logarithmic function. The water absorption rate was negatively correlated with immersion time, conforming to a power function. At any given immersion time, the S. superba forest exhibited the highest litter water holding capacity and water absorption rate. ③ Soil bulk density of the different forest types ranged from 1.22 - 1.49 g/cm3, with the S. superba forest showing the highest value and the S. tzumu forest the lowest. Soil porosity ranged from 43.89% to 53.82%, exhibiting a negative correlation with bulk density. The saturation water holding capacity and maximum water holding capacity ranged from 877.74 - 1 076.30 t/ha and 591.27 - 849.80 t/ha, respectively, with both parameters being highest in the S. tzumu forest. Comprehensive evaluation indicates that the S. superba forest in the Danxia Mountain area demonstrates significant advantages in both litter and soil water holding capacity. [Conclusion] Therefore, it is recommended that priority be given to increasing the proportion of the S. superba forest in regional forest management strategies to enhance the overall water conservation and soil water holding functions of the ecosystem.
Abstract:
[Objective] Soil erosion control has long been a research focus in soil and water conservation, and the integration of multiple methods represents a current hotspot. This study analyzes the synergistic effects of vegetation and Microbial-Induced Carbonate Precipitation (MICP), aiming to reveal the effectiveness of this combined approach for slope protection and its impact on hydrological and soil erosion processes, thereby providing new insights and technologies for slope soil erosion control. [Methods] This study conducted five groups of experiments, including a bare soil control group (CK), an MICP treatment group (MR), and three plants (Festuca Arundinacea FA, Medicago Sativa MS, and Chrysopogon Zizanioides CZ) respectively in combination with MICP for protective measures (FA-MC, MS-MC, CZ-MC). Based on a surface water-groundwater coupled model, a soil erosion model was constructed to quantitatively analyze soil erosion rates under these different slope protection designs. Techniques including direct shear tests, microscopic observation, and scanning electron microscopy (SEM) were utilized to comprehensively analyze the variations and underlying mechanisms of cohesion (c) and the internal friction angle (φ). [Results] The results demonstrated that: (1) The MICP treatment effectively cemented loose soil particles by filling soil pores with flaky and flocculent CaCO? precipitates, leading to a significant increase in the c value. It also reduced porosity and increased surface roughness, resulting in a higher φ value. The synergistic action of vegetation and MICP further enhanced both c and φ, with maximum increases of 402.81% and 33.91%, respectively, compared to the CK group. (2) The numerical model effectively simulated the runoff volume and soil erosion rate across the five experimental groups (with maximum mean absolute errors of 2.39×10?? m/s and 1.77×10?2 g/m2/s, respectively), providing a useful tool for analyzing hydrological and soil erosion processes under the synergistic effects of vegetation and MICP. (3) The synergistic effect of plants and Microbially Induced Calcite Precipitation (MICP) can not only significantly enhance soil strength but also improve soil permeability and water retention capacity. Moreover, through multiple erosion?reduction mechanisms (including plant interception and energy dissipation, water storage and flow diversion, and runoff interception), this synergistic system delivers integrated benefits of soil reinforcement, water conservation, and erosion mitigation. [Conclusions] The synergistic effect of plant and MICP could improve soil properties and reduce rainfall splash erosion and erosion on slope, thereby regulating soil erosion process. The developed numerical model can serve as an important tool for analyzing the soil and water conservation performance of different slope protection designs during soil erosion research.
[Objective] Soil erosion control has long been a research focus in soil and water conservation, and the integration of multiple methods represents a current hotspot. This study analyzes the synergistic effects of vegetation and Microbial-Induced Carbonate Precipitation (MICP), aiming to reveal the effectiveness of this combined approach for slope protection and its impact on hydrological and soil erosion processes, thereby providing new insights and technologies for slope soil erosion control. [Methods] This study conducted five groups of experiments, including a bare soil control group (CK), an MICP treatment group (MR), and three plants (Festuca Arundinacea FA, Medicago Sativa MS, and Chrysopogon Zizanioides CZ) respectively in combination with MICP for protective measures (FA-MC, MS-MC, CZ-MC). Based on a surface water-groundwater coupled model, a soil erosion model was constructed to quantitatively analyze soil erosion rates under these different slope protection designs. Techniques including direct shear tests, microscopic observation, and scanning electron microscopy (SEM) were utilized to comprehensively analyze the variations and underlying mechanisms of cohesion (c) and the internal friction angle (φ). [Results] The results demonstrated that: (1) The MICP treatment effectively cemented loose soil particles by filling soil pores with flaky and flocculent CaCO? precipitates, leading to a significant increase in the c value. It also reduced porosity and increased surface roughness, resulting in a higher φ value. The synergistic action of vegetation and MICP further enhanced both c and φ, with maximum increases of 402.81% and 33.91%, respectively, compared to the CK group. (2) The numerical model effectively simulated the runoff volume and soil erosion rate across the five experimental groups (with maximum mean absolute errors of 2.39×10?? m/s and 1.77×10?2 g/m2/s, respectively), providing a useful tool for analyzing hydrological and soil erosion processes under the synergistic effects of vegetation and MICP. (3) The synergistic effect of plants and Microbially Induced Calcite Precipitation (MICP) can not only significantly enhance soil strength but also improve soil permeability and water retention capacity. Moreover, through multiple erosion?reduction mechanisms (including plant interception and energy dissipation, water storage and flow diversion, and runoff interception), this synergistic system delivers integrated benefits of soil reinforcement, water conservation, and erosion mitigation. [Conclusions] The synergistic effect of plant and MICP could improve soil properties and reduce rainfall splash erosion and erosion on slope, thereby regulating soil erosion process. The developed numerical model can serve as an important tool for analyzing the soil and water conservation performance of different slope protection designs during soil erosion research.
Abstract:
[Objective] This study aims to investigate the impact of wind farm construction and operation on alpine meadow vegetation and soil nutrients around the Mouton Mountain Wind Farm in Yunnan Province, and to clarify the main driving factors, thereby providing a theoretical basis for the restoration of degraded grasslands in such areas.[Methods] This study employed a systematic combination of field surveys and laboratory analyses. Three turbine plots within the Mouton Mountain Wind Farm in Yuxi City, Yunnan Province, and three control plots without turbines were selected. Within each plot, sampling points were established at four directions (northwest, northeast, southeast, southwest) and at distances of 0, 20, 50, and 100 meters from the turbine base (or central point for control plots). A comparative analysis of vegetation characteristics and soil nutrients was conducted to elucidate the ecological effects of wind farm construction and operation on local vegetation and soil.[Results] 1. The presence of wind turbines highly significantly reduced aboveground vegetation biomass (P < 0.01) and the plant community diversity index (P < 0.05). Both aboveground biomass and vegetation diversity in the wind farm construction area were significantly lower than those in the control plots. Within the turbine area, aboveground biomass increased highly significantly with increasing distance (P < 0.01), reaching its highest level at 100 m. The diversity index was significantly influenced by direction (P < 0.05), with the southwest direction exhibiting the highest values.2. The presence of wind turbines highly significantly reduced soil organic matter, total nitrogen, and water content (P < 0.001), and significantly increased soil pH (P < 0.05). The contents of soil organic matter, total nitrogen, and water content within the wind farm construction area increased with larger wind turbine radiation radius. 3. The wind turbine radiation radius exerted a significant influence on the soil available potassium content (P < 0.05). The soil available potassium content in the wind farm construction area increased with the enlargement of the radiation radius. 4. There was no significant difference of turbine presence on soil AP content (P > 0.05). [Conclusion] The construction and operation of the wind farm had significant negative impacts on surrounding vegetation and soil nutrients, and the intensity of these impacts weakened with increasing distance from the turbine. Therefore, ecological restoration should follow a zonal management principle: active restoration focusing on soil improvement and vegetation reconstruction should be implemented in the high-intensity disturbance zone within 20 m of the turbine; natural restoration supplemented by artificial promotion measures should be adopted in the medium-low intensity disturbance zone between 20-100 m. This study provides a scientific basis for differentiated ecological restoration in high-altitude wind farm areas.
[Objective] This study aims to investigate the impact of wind farm construction and operation on alpine meadow vegetation and soil nutrients around the Mouton Mountain Wind Farm in Yunnan Province, and to clarify the main driving factors, thereby providing a theoretical basis for the restoration of degraded grasslands in such areas.[Methods] This study employed a systematic combination of field surveys and laboratory analyses. Three turbine plots within the Mouton Mountain Wind Farm in Yuxi City, Yunnan Province, and three control plots without turbines were selected. Within each plot, sampling points were established at four directions (northwest, northeast, southeast, southwest) and at distances of 0, 20, 50, and 100 meters from the turbine base (or central point for control plots). A comparative analysis of vegetation characteristics and soil nutrients was conducted to elucidate the ecological effects of wind farm construction and operation on local vegetation and soil.[Results] 1. The presence of wind turbines highly significantly reduced aboveground vegetation biomass (P < 0.01) and the plant community diversity index (P < 0.05). Both aboveground biomass and vegetation diversity in the wind farm construction area were significantly lower than those in the control plots. Within the turbine area, aboveground biomass increased highly significantly with increasing distance (P < 0.01), reaching its highest level at 100 m. The diversity index was significantly influenced by direction (P < 0.05), with the southwest direction exhibiting the highest values.2. The presence of wind turbines highly significantly reduced soil organic matter, total nitrogen, and water content (P < 0.001), and significantly increased soil pH (P < 0.05). The contents of soil organic matter, total nitrogen, and water content within the wind farm construction area increased with larger wind turbine radiation radius. 3. The wind turbine radiation radius exerted a significant influence on the soil available potassium content (P < 0.05). The soil available potassium content in the wind farm construction area increased with the enlargement of the radiation radius. 4. There was no significant difference of turbine presence on soil AP content (P > 0.05). [Conclusion] The construction and operation of the wind farm had significant negative impacts on surrounding vegetation and soil nutrients, and the intensity of these impacts weakened with increasing distance from the turbine. Therefore, ecological restoration should follow a zonal management principle: active restoration focusing on soil improvement and vegetation reconstruction should be implemented in the high-intensity disturbance zone within 20 m of the turbine; natural restoration supplemented by artificial promotion measures should be adopted in the medium-low intensity disturbance zone between 20-100 m. This study provides a scientific basis for differentiated ecological restoration in high-altitude wind farm areas.
Huang Shaoping, Huang Jingyu, Wan Hao, Lei Zhiqian, Xiao Henglin, Wang Qin, Li Yao, Wang An, Zhang Zhiyong, Zhang Wengang, Cui Xinzhuang
Abstract:
[Objective] This study aims to elucidate the seasonal variation characteristics of soil respiration rates beneath typical slope-stabilizing Cynodon dactylon cover and its response patterns to critical environmental factors, thereby revealing the environmental response properties of soil carbon release processes associated with Cynodon dactylon while excluding the influence of complex hydrological processes. This offers essential process-oriented evidence for assessing its ecological advantages in slope stabilization and possible carbon sequestration capabilities. [Methods] Continuous studies of the soil respiration rate of Cynodon dactylon during its growing season were undertaken using devices such as the 3051T completely automatic soil CO? flux meter and a solar-powered weather station. Simultaneous monitoring was conducted on environmental variables such as air temperature and humidity, soil temperature and humidity, atmospheric CO? levels, and precipitation. This study examines the impact of many environmental conditions on fluctuations in soil respiration rates on Bermuda grass-protected slopes by assessing changes across daily, monthly, and seasonal periods, with correlation analysis.[Results] (1) Under Cynodon dactylon cover, soil respiration rates displayed significant seasonal fluctuation throughout the growing season, peaking in summer, followed by spring, and reaching lowest levels in fall. On a daily scale, respiration rates demonstrated either single-peak or double-peak patterns throughout different months, with peak timing altering seasonally. (2) Correlation analysis revealed extremely substantial positive relationships between soil respiration rates and both air temperature and soil temperature (P < 0.01). Significant negative relationships were identified with soil moisture (P < 0.01) and ambient CO? concentration (P < 0.05), while no significant association was found with air humidity. (3) Soil respiration rates exhibit a nonlinear relationship with temperature, decreasing as temperatures rise under higher temperature conditions. (4) Within 72 hours after rainfall, overall soil respiration rates were lower than under no-precipitation conditions, with a trend consistent with the control group.
[Objective] This study aims to elucidate the seasonal variation characteristics of soil respiration rates beneath typical slope-stabilizing Cynodon dactylon cover and its response patterns to critical environmental factors, thereby revealing the environmental response properties of soil carbon release processes associated with Cynodon dactylon while excluding the influence of complex hydrological processes. This offers essential process-oriented evidence for assessing its ecological advantages in slope stabilization and possible carbon sequestration capabilities. [Methods] Continuous studies of the soil respiration rate of Cynodon dactylon during its growing season were undertaken using devices such as the 3051T completely automatic soil CO? flux meter and a solar-powered weather station. Simultaneous monitoring was conducted on environmental variables such as air temperature and humidity, soil temperature and humidity, atmospheric CO? levels, and precipitation. This study examines the impact of many environmental conditions on fluctuations in soil respiration rates on Bermuda grass-protected slopes by assessing changes across daily, monthly, and seasonal periods, with correlation analysis.[Results] (1) Under Cynodon dactylon cover, soil respiration rates displayed significant seasonal fluctuation throughout the growing season, peaking in summer, followed by spring, and reaching lowest levels in fall. On a daily scale, respiration rates demonstrated either single-peak or double-peak patterns throughout different months, with peak timing altering seasonally. (2) Correlation analysis revealed extremely substantial positive relationships between soil respiration rates and both air temperature and soil temperature (P < 0.01). Significant negative relationships were identified with soil moisture (P < 0.01) and ambient CO? concentration (P < 0.05), while no significant association was found with air humidity. (3) Soil respiration rates exhibit a nonlinear relationship with temperature, decreasing as temperatures rise under higher temperature conditions. (4) Within 72 hours after rainfall, overall soil respiration rates were lower than under no-precipitation conditions, with a trend consistent with the control group.
Abstract:
[Objective] To achieve high-precision monitoring of soil organic matter in saline-alkali farmland, this study proposes a framework integrating fractional-order differentiation (FOD), continuous wavelet transform (CWT), and spectral index construction. [Method] Two saline-alkali farmland plots in Jiashi County, Xinjiang, were selected as the study area. Ground-based hyperspectral reflectance data and field sampling data were used as data sources. The original hyperspectral reflectance was subjected to differential transformation with a step size of 0.25. On this basis, continuous wavelet transform was performed at six scales, and the optimal combination of differential order and wavelet decomposition scale was selected to construct a ratio index (RI), difference index (DI), and normalized index (NDI). Random forest (RF), extreme gradient boosting (XGBoost), support vector regression (SVR), and light gradient boosting machine (LightGBM) models were built to quantitatively estimate soil organic matter content. [Result] The results show that after FOD processing, the 0.75-order differential spectrum had the highest correlation with organic matter, significantly outperforming the original spectrum and integer-order transformation. After the combined FOD_CWT processing, the 0.25-order FOD combined with 25-scale CWT showed the best performance, with a correlation coefficient of 0.726. The correlation between spectral reflectance data and organic matter increased by 0.197, effectively enhancing the relationship between the spectrum and soil organic matter. The FOD_CWT_XGBoost combination showed the best prediction performance, with a test set R2 of 0.744. [Conclusion] The combination of fractional-order differentiation and wavelet transform can deeply extract spectral information, and the constructed model is suitable for estimating soil organic matter.
[Objective] To achieve high-precision monitoring of soil organic matter in saline-alkali farmland, this study proposes a framework integrating fractional-order differentiation (FOD), continuous wavelet transform (CWT), and spectral index construction. [Method] Two saline-alkali farmland plots in Jiashi County, Xinjiang, were selected as the study area. Ground-based hyperspectral reflectance data and field sampling data were used as data sources. The original hyperspectral reflectance was subjected to differential transformation with a step size of 0.25. On this basis, continuous wavelet transform was performed at six scales, and the optimal combination of differential order and wavelet decomposition scale was selected to construct a ratio index (RI), difference index (DI), and normalized index (NDI). Random forest (RF), extreme gradient boosting (XGBoost), support vector regression (SVR), and light gradient boosting machine (LightGBM) models were built to quantitatively estimate soil organic matter content. [Result] The results show that after FOD processing, the 0.75-order differential spectrum had the highest correlation with organic matter, significantly outperforming the original spectrum and integer-order transformation. After the combined FOD_CWT processing, the 0.25-order FOD combined with 25-scale CWT showed the best performance, with a correlation coefficient of 0.726. The correlation between spectral reflectance data and organic matter increased by 0.197, effectively enhancing the relationship between the spectrum and soil organic matter. The FOD_CWT_XGBoost combination showed the best prediction performance, with a test set R2 of 0.744. [Conclusion] The combination of fractional-order differentiation and wavelet transform can deeply extract spectral information, and the constructed model is suitable for estimating soil organic matter.
Abstract:
[Objective] Dry–wet cycles can disrupt soil structure and reduce soil stability, and are recognized as an important driving factor in the rapid development of erosion gullies. To clarify the differences in erosion resistance among soil layers on gully sidewalls under dry–wet cycling, this study conducted experimental analyses on typical gully walls in the black soil region of Northeast China and examined the influence of dry–wet alternation on gully erosion processes. [Methods] Soil samples were collected from gully sidewalls of cultivated land in the black soil region at depths of 0–30 cm, 30–60 cm, and 60–90 cm. A laboratory-simulated dry–wet cycling experiment was conducted to determine soil mechanical composition, water-stable aggregates (WSA), soil disintegration rate (SDR), and soil anti-scour coefficient (ANS). Differences and variation patterns in erosion resistance among the three soil layers were analyzed and compared. [Results] Dry–wet cycles significantly affected WSA, SDR, and ANS in all three soil layers. After one cycle, dry–wet alternation exerted generally positive effects, with aggregate breakdown rate (PAD) decreasing by 0.23%, 7.28%, and 0.43% in the 0–30 cm, 30–60 cm, and 60–90 cm layers, respectively. Meanwhile, the anti-scour coefficient increased by 171.03 L.g?1 in the 0–30 cm layer and by 287.84 L.g?1 in the 30–60 cm layer. After five cycles, the strongest response occurred in the 0–30 cm layer, where SDR increased by 72.29 g.s?1, while in the 60–90 cm layer, PAD increased by 1.33% and SDR decreased by 6.1 g.s?1. After eight cycles, PAD increased by 4.315% and 7.78% in the 0–30 cm and 30–60 cm layers, respectively. Overall, WSA in the 0–30 cm layer decreased and SDR increased markedly with increasing cycle number, although its relatively high organic matter content helped maintain strong resistance to scouring. The 30–60 cm layer exhibited improved water stability after one cycle, indicating temporary structural enhancement; however, structural degradation and reduced anti-scour resistance occurred after 5–8 cycles, although resistance to disintegration remained higher than the initial state. The 60–90 cm layer showed poor water stability, high SDR, and weak anti-scour capacity, and its structure was difficult to recover once damaged. [Conclusion] Dry–wet cycles intensified the vertical differentiation of erosion resistance along gully sidewalls, with the surface layer remaining relatively stable, the middle layer exhibiting pronounced fluctuations, and the deep layer being the most vulnerable. This process promotes gully wall collapse and accelerates gully expansion, providing important implications for soil and water conservation and gully erosion control in black soil regions. Management strategies should therefore emphasize structural improvement and enhancement of anti-scour capacity, particularly in the middle and lower soil layers.
[Objective] Dry–wet cycles can disrupt soil structure and reduce soil stability, and are recognized as an important driving factor in the rapid development of erosion gullies. To clarify the differences in erosion resistance among soil layers on gully sidewalls under dry–wet cycling, this study conducted experimental analyses on typical gully walls in the black soil region of Northeast China and examined the influence of dry–wet alternation on gully erosion processes. [Methods] Soil samples were collected from gully sidewalls of cultivated land in the black soil region at depths of 0–30 cm, 30–60 cm, and 60–90 cm. A laboratory-simulated dry–wet cycling experiment was conducted to determine soil mechanical composition, water-stable aggregates (WSA), soil disintegration rate (SDR), and soil anti-scour coefficient (ANS). Differences and variation patterns in erosion resistance among the three soil layers were analyzed and compared. [Results] Dry–wet cycles significantly affected WSA, SDR, and ANS in all three soil layers. After one cycle, dry–wet alternation exerted generally positive effects, with aggregate breakdown rate (PAD) decreasing by 0.23%, 7.28%, and 0.43% in the 0–30 cm, 30–60 cm, and 60–90 cm layers, respectively. Meanwhile, the anti-scour coefficient increased by 171.03 L.g?1 in the 0–30 cm layer and by 287.84 L.g?1 in the 30–60 cm layer. After five cycles, the strongest response occurred in the 0–30 cm layer, where SDR increased by 72.29 g.s?1, while in the 60–90 cm layer, PAD increased by 1.33% and SDR decreased by 6.1 g.s?1. After eight cycles, PAD increased by 4.315% and 7.78% in the 0–30 cm and 30–60 cm layers, respectively. Overall, WSA in the 0–30 cm layer decreased and SDR increased markedly with increasing cycle number, although its relatively high organic matter content helped maintain strong resistance to scouring. The 30–60 cm layer exhibited improved water stability after one cycle, indicating temporary structural enhancement; however, structural degradation and reduced anti-scour resistance occurred after 5–8 cycles, although resistance to disintegration remained higher than the initial state. The 60–90 cm layer showed poor water stability, high SDR, and weak anti-scour capacity, and its structure was difficult to recover once damaged. [Conclusion] Dry–wet cycles intensified the vertical differentiation of erosion resistance along gully sidewalls, with the surface layer remaining relatively stable, the middle layer exhibiting pronounced fluctuations, and the deep layer being the most vulnerable. This process promotes gully wall collapse and accelerates gully expansion, providing important implications for soil and water conservation and gully erosion control in black soil regions. Management strategies should therefore emphasize structural improvement and enhancement of anti-scour capacity, particularly in the middle and lower soil layers.
Abstract:
[Objective] Groundwater, as a vital component of water resources, objectively reveals the sources of heavy metal contamination and associated health risks. This information holds significant importance for the rational utilization and effective management of groundwater in agricultural areas. [Methods] Using 119 representative sampling sites in eastern Henan Province, this study selected 10 heavy metals (Zn, Pb, Cr, As, Cu, Fe, Mn, Al, Hg, and Ni) were analyzed at 119 representative sampling sites in eastern Henan Province. By integrating single-factor pollution indices, the Nemero composite index, absolute factor analysis-multivariate linear regression (APCS-MLR), and health risk assessment models, this study examined groundwater heavy metal content characteristics, spatial distribution, and pollution status to identify pollution sources and evaluate health risks. [Results] ①The average concentrations of groundwater heavy metals in eastern Henan Province, ranked from highest to lowest, were Mn > Zn > Al > Fe > Cu > As > Ni > Pb > Cr > Hg. The average Mn concentration exceeded the Class III standard limit specified in the “Groundwater Quality Standard (GB/T 14848-2017)”, while concentrations of As, Pb, and Ni at some sampling points exceeded the national Class III standard limits. ②Regarding single-factor pollution levels for each heavy metal in Eastern Henan, Mn exhibited severe pollution while all others remained clean. The proportions of sampling points showing mild and severe pollution were 36.13% and 31.09%, respectively. Mn was identified as the dominant factor in groundwater heavy metal pollution. ③The average contribution rates of industrial sources, unknown sources, agricultural sources, natural sources, and traffic sources decrease in that order, accounting for 41.44%, 20.81%, 18.72%, 12.57%, and 6.46%, respectively. However, the contributions of different sources to various heavy metals exhibit significant variability. ④Under drinking water intake and dermal contact pathways, the health risks posed by non-carcinogenic and carcinogenic elements to both adults and children remain within acceptable limits. [Conclusion] The heavy metal content in groundwater in the eastern Henan region exhibits variability, posing risks to human health within acceptable limits. However, targeted measures should be implemented based on the pollution status and sources of individual elements to enhance groundwater heavy metal utilization and management, while dynamically monitoring their health risk status.
[Objective] Groundwater, as a vital component of water resources, objectively reveals the sources of heavy metal contamination and associated health risks. This information holds significant importance for the rational utilization and effective management of groundwater in agricultural areas. [Methods] Using 119 representative sampling sites in eastern Henan Province, this study selected 10 heavy metals (Zn, Pb, Cr, As, Cu, Fe, Mn, Al, Hg, and Ni) were analyzed at 119 representative sampling sites in eastern Henan Province. By integrating single-factor pollution indices, the Nemero composite index, absolute factor analysis-multivariate linear regression (APCS-MLR), and health risk assessment models, this study examined groundwater heavy metal content characteristics, spatial distribution, and pollution status to identify pollution sources and evaluate health risks. [Results] ①The average concentrations of groundwater heavy metals in eastern Henan Province, ranked from highest to lowest, were Mn > Zn > Al > Fe > Cu > As > Ni > Pb > Cr > Hg. The average Mn concentration exceeded the Class III standard limit specified in the “Groundwater Quality Standard (GB/T 14848-2017)”, while concentrations of As, Pb, and Ni at some sampling points exceeded the national Class III standard limits. ②Regarding single-factor pollution levels for each heavy metal in Eastern Henan, Mn exhibited severe pollution while all others remained clean. The proportions of sampling points showing mild and severe pollution were 36.13% and 31.09%, respectively. Mn was identified as the dominant factor in groundwater heavy metal pollution. ③The average contribution rates of industrial sources, unknown sources, agricultural sources, natural sources, and traffic sources decrease in that order, accounting for 41.44%, 20.81%, 18.72%, 12.57%, and 6.46%, respectively. However, the contributions of different sources to various heavy metals exhibit significant variability. ④Under drinking water intake and dermal contact pathways, the health risks posed by non-carcinogenic and carcinogenic elements to both adults and children remain within acceptable limits. [Conclusion] The heavy metal content in groundwater in the eastern Henan region exhibits variability, posing risks to human health within acceptable limits. However, targeted measures should be implemented based on the pollution status and sources of individual elements to enhance groundwater heavy metal utilization and management, while dynamically monitoring their health risk status.
Abstract:
Karst rocky desertification control remains challenging due to low vegetation survival and poor technical adaptability. Understanding of rock-dwelling mosses, as pioneer species, is still limited regarding their quantitative responses across microhabitats and the coupled regulatory effects of multiple environmental factors. [Objective] To explore their soil stabilization and water retention effects in Karst rocky desertification mountains and identify the influencing factors, this study focuses on exposed rock habitats in typical Karst desertification areas of Guizhou, including corn cropland, reclaimed grassland, and peach orchard land. [Method] We measured moss growth characteristics (thickness, cover, dry weight, biomass, chlorophyll), soil stabilization and water retention properties (water retention rate, soil stabilization rate), and environmental factors (light, temperature/humidity, rock surface orientation) in 267 sample plots. [Results] Results show that the peach orchard provides the best habitat for moss growth, with thickness (11.81 mm), cover (85.82%), and biomass (5.51×103 kg/hm2) 53.5%, 56.6%, and 95.0% higher than cropland in the same direction. The orchard also exhibited the highest water retention (54.18×103 kg/hm2) and soil stabilization (12.56×103 kg/hm2). On north-facing slopes (300°-345°) with 65%-80% humidity, the soil stabilization rate reached 88%-92%. Water retention decreased by 47.3% when light exceeded 6000 Lux, and soil stabilization increased with humidity and decreased with slope. [Conclusion] The synergistic regulation of land use and microhabitat determines the soil stabilization and water retention effects of rock-dwelling mosses, with excessive light and low humidity as key stress factors. The north-facing gentle slopes in peach orchards represent the optimal microhabitat, providing a basis for precision microhabitat restoration in rocky desertification areas.
Karst rocky desertification control remains challenging due to low vegetation survival and poor technical adaptability. Understanding of rock-dwelling mosses, as pioneer species, is still limited regarding their quantitative responses across microhabitats and the coupled regulatory effects of multiple environmental factors. [Objective] To explore their soil stabilization and water retention effects in Karst rocky desertification mountains and identify the influencing factors, this study focuses on exposed rock habitats in typical Karst desertification areas of Guizhou, including corn cropland, reclaimed grassland, and peach orchard land. [Method] We measured moss growth characteristics (thickness, cover, dry weight, biomass, chlorophyll), soil stabilization and water retention properties (water retention rate, soil stabilization rate), and environmental factors (light, temperature/humidity, rock surface orientation) in 267 sample plots. [Results] Results show that the peach orchard provides the best habitat for moss growth, with thickness (11.81 mm), cover (85.82%), and biomass (5.51×103 kg/hm2) 53.5%, 56.6%, and 95.0% higher than cropland in the same direction. The orchard also exhibited the highest water retention (54.18×103 kg/hm2) and soil stabilization (12.56×103 kg/hm2). On north-facing slopes (300°-345°) with 65%-80% humidity, the soil stabilization rate reached 88%-92%. Water retention decreased by 47.3% when light exceeded 6000 Lux, and soil stabilization increased with humidity and decreased with slope. [Conclusion] The synergistic regulation of land use and microhabitat determines the soil stabilization and water retention effects of rock-dwelling mosses, with excessive light and low humidity as key stress factors. The north-facing gentle slopes in peach orchards represent the optimal microhabitat, providing a basis for precision microhabitat restoration in rocky desertification areas.
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[Objective ] Vegetation type is one of the key factors affecting soil respiration. This study aimed to measure and compare soil respiration rates of young plantations of Populus simonii × P. nigra and Amorpha fruticosa established on black soils with different degradation levels, and to analyze the effects of environmental factors on soil respiration of young plantations, in order to clarify the differential roles of these tree-type and shrub-type restoration measures in soil carbon emission from degraded black soils.[Methods] From May to October 2024 (on degradation gradients constructed in 2022), soil respiration rates were continuously measured in situ using a portable soil carbon flux system (LI-870) at Keshan Farm, Qiqihar. Mildly, moderately and severely degraded black soils were planted with Populus simonii × P. nigra and Amorpha fruticosa young plantations, with corresponding bare control plots; all plots had an area of 4 m × 7 m. Soil respiration rates of the two plantations and the controls were compared among degradation levels, and the underlying mechanisms were further explored using Pearson correlation analysis, redundancy analysis (RDA) and partial least squares path modeling (PLS-PM). [Results] Vegetation type, soil degradation level and their interaction had highly significant effects on soil respiration rate (P < 0.001). For both plantations, soil respiration on all three degradation levels showed pronounced seasonal dynamics, with maxima in July and August. The mean soil respiration rates of Populus simonii × P. nigra , Amorpha fruticosa and the control all decreased significantly with increasing degradation degree (P < 0.05). Across degradation levels, the mean soil respiration rate in Amorpha fruticosa plantations (2.31 μmol CO? m?2 s?1) was generally higher than that in Populus simonii × P. nigra plantations (1.96 μmol CO? m?2 s?1). Model fitting showed that soil temperature at 5 cm depth was exponentially and significantly related to soil respiration, whereas soil volumetric water content alone was not significantly correlated with soil respiration, but its interaction with temperature significantly affected soil respiration in the different plantations (P < 0.05). Pearson's correlation analysis showed a highly significant positive correlation (P < 0.01) between Rs and soil 5 cm temperature and alkali-hydrolyzable N. RDA indicated that soil respiration rate was significantly and positively correlated with total N, available P, total P, alkali-hydrolyzable N, 5-cm soil temperature and volumetric water content (P < 0.05). PLS-PM further showed that plant species and soil degradation degree affected soil respiration both directly and indirectly through their effects on soil temperature and soil nutrients. [Conclusion ]Establishing young plantations of Populus simonii × P. nigra and Amorpha fruticosa significantly increased soil respiration rates of degraded black soils compared with bare controls (P < 0.05), and in mildly degraded soils the mean soil respiration under Amorpha fruticosa plantations was significantly higher than under Populus simonii × P. nigra (P < 0.05). Soil temperature is the key factor driving the temporal variation of soil respiration, and, through its coupling with soil nutrients, it mediates the effects of plant species and soil degradation degree on soil respiration.
[Objective ] Vegetation type is one of the key factors affecting soil respiration. This study aimed to measure and compare soil respiration rates of young plantations of Populus simonii × P. nigra and Amorpha fruticosa established on black soils with different degradation levels, and to analyze the effects of environmental factors on soil respiration of young plantations, in order to clarify the differential roles of these tree-type and shrub-type restoration measures in soil carbon emission from degraded black soils.[Methods] From May to October 2024 (on degradation gradients constructed in 2022), soil respiration rates were continuously measured in situ using a portable soil carbon flux system (LI-870) at Keshan Farm, Qiqihar. Mildly, moderately and severely degraded black soils were planted with Populus simonii × P. nigra and Amorpha fruticosa young plantations, with corresponding bare control plots; all plots had an area of 4 m × 7 m. Soil respiration rates of the two plantations and the controls were compared among degradation levels, and the underlying mechanisms were further explored using Pearson correlation analysis, redundancy analysis (RDA) and partial least squares path modeling (PLS-PM). [Results] Vegetation type, soil degradation level and their interaction had highly significant effects on soil respiration rate (P < 0.001). For both plantations, soil respiration on all three degradation levels showed pronounced seasonal dynamics, with maxima in July and August. The mean soil respiration rates of Populus simonii × P. nigra , Amorpha fruticosa and the control all decreased significantly with increasing degradation degree (P < 0.05). Across degradation levels, the mean soil respiration rate in Amorpha fruticosa plantations (2.31 μmol CO? m?2 s?1) was generally higher than that in Populus simonii × P. nigra plantations (1.96 μmol CO? m?2 s?1). Model fitting showed that soil temperature at 5 cm depth was exponentially and significantly related to soil respiration, whereas soil volumetric water content alone was not significantly correlated with soil respiration, but its interaction with temperature significantly affected soil respiration in the different plantations (P < 0.05). Pearson's correlation analysis showed a highly significant positive correlation (P < 0.01) between Rs and soil 5 cm temperature and alkali-hydrolyzable N. RDA indicated that soil respiration rate was significantly and positively correlated with total N, available P, total P, alkali-hydrolyzable N, 5-cm soil temperature and volumetric water content (P < 0.05). PLS-PM further showed that plant species and soil degradation degree affected soil respiration both directly and indirectly through their effects on soil temperature and soil nutrients. [Conclusion ]Establishing young plantations of Populus simonii × P. nigra and Amorpha fruticosa significantly increased soil respiration rates of degraded black soils compared with bare controls (P < 0.05), and in mildly degraded soils the mean soil respiration under Amorpha fruticosa plantations was significantly higher than under Populus simonii × P. nigra (P < 0.05). Soil temperature is the key factor driving the temporal variation of soil respiration, and, through its coupling with soil nutrients, it mediates the effects of plant species and soil degradation degree on soil respiration.
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Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
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[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
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[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
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[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
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[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
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[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
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[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
Abstract:
[Objective] Analyzing the spatial-temporal evolution and influencing factors of carbon emissions in Qingdao City is of great significance for ecological protection and high-quality development.[Methods] Based on the land use data, nighttime light data, and social and economic data of Qingdao city from 2000 to 2020, carbon emissions from land use were calculated. By constructing a fitting model between carbon emissions and nighttime light values, the spatial distribution difference and trend of carbon emissions of different land use types in Qingdao city were revealed. The decoupling status between carbon emissions and economic development in Qingdao city was analyzed through the Tapio decoupling model. The contribution degree of various influencing factors of land use carbon emissions was analyzed by using Kaya decomposition and LMDI models. [Results] ①The net carbon emissions from land use in Qingdao city generally showed an increasing trend from 2000 to 2020. From 13,096,400 tons in 2000 to 36.4820 million tons in 2020, an increase of nearly 1.79 times;②The overall carbon emissions in Qingdao city presented a spatial distribution pattern of "high in the middle and low around", and industrial energy consumption was the main source of carbon emissions from construction land, with high carbon emission areas mainly concentrated in the Jiaozhou Bay area;③The relationship between economic development and carbon emissions in Qingdao city has undergone a transition from "expansion link to weak decoupling to strong decoupling";④The factors that promote the growth of carbon emissions in Qingdao are population size and economic effect, and the factors that inhibit the growth of carbon emissions in Qingdao are energy structure and energy intensity. [Conclusion] In the future, it is necessary to further adjust the industrial structure, accelerate the development of a low-carbon economy, and reduce carbon emissions from the source through measures such as technological innovation and energy structure adjustment.
[Objective] Analyzing the spatial-temporal evolution and influencing factors of carbon emissions in Qingdao City is of great significance for ecological protection and high-quality development.[Methods] Based on the land use data, nighttime light data, and social and economic data of Qingdao city from 2000 to 2020, carbon emissions from land use were calculated. By constructing a fitting model between carbon emissions and nighttime light values, the spatial distribution difference and trend of carbon emissions of different land use types in Qingdao city were revealed. The decoupling status between carbon emissions and economic development in Qingdao city was analyzed through the Tapio decoupling model. The contribution degree of various influencing factors of land use carbon emissions was analyzed by using Kaya decomposition and LMDI models. [Results] ①The net carbon emissions from land use in Qingdao city generally showed an increasing trend from 2000 to 2020. From 13,096,400 tons in 2000 to 36.4820 million tons in 2020, an increase of nearly 1.79 times;②The overall carbon emissions in Qingdao city presented a spatial distribution pattern of "high in the middle and low around", and industrial energy consumption was the main source of carbon emissions from construction land, with high carbon emission areas mainly concentrated in the Jiaozhou Bay area;③The relationship between economic development and carbon emissions in Qingdao city has undergone a transition from "expansion link to weak decoupling to strong decoupling";④The factors that promote the growth of carbon emissions in Qingdao are population size and economic effect, and the factors that inhibit the growth of carbon emissions in Qingdao are energy structure and energy intensity. [Conclusion] In the future, it is necessary to further adjust the industrial structure, accelerate the development of a low-carbon economy, and reduce carbon emissions from the source through measures such as technological innovation and energy structure adjustment.
Abstract:
[Objective]Within the framework of the dual carbon target vision, addressing the scale effects of forest land changes and quantifying the carbon sequestration benefits at multiple watershed levels not only introduce a fresh perspective into forest land research but also aid in cording and optimizing the forest land pattern. That holds great significance in enhancing future regional carbon sequestration potential.[Methods]Focusing on Chongqing as the study area, we analyzed the spatiotemporal dynamic changes in forest land and carbon storage from 2000 to 2030 at the multi-watershed scale, utilizing PLUS model, landscape pattern indices, biomass expansion factor method and grey correlation degree. Furthermore, we explored the correlation between forest land pattern changes and carbon storage under natural development scenarios.[Results](1)Between 2000 and 2020,the forest area increased by 3404.55 km2,primarily due to the conversion of cultivated land. The forest landscape pattern in the first-grade watershed showed a tendency towards clustering and regularity, with a relatively reduced degree of fragmentation. There were distinct differences in the historical laws and future trends of forest landscape pattern changes in the secondary watershed’s “district and group”.(2)In the initial two decades, the carbon storage of forest land exhibited an increasing-decreasing trend, resulting in an overall increase. The Dongting Lake system in the first level basin witnessed the highest increase in carbon storage, and the high-value area of carbon storage increment in the seconde level basin shifted from north to south.(3)The total carbon storage is predicted to increase by 2030 which is strongly correlated with the irregular index. The scale effect leads to the spatial heterogeneity of landscape pattern change and the correlation degree between landscape pattern index and carbon storage in the primary and secondary basins.[Conclusion]The research outcome contribute to understanding the patterns of forest land changes from a cross-watershed scale perspective. This, in turn, provides a scientific foundation for the Ministry of Natural Resource or relevant forestry departments to formulate effective utilization and protection policies for forest land resources at different scales, It also supports the sustainable development of Chongqing, enhances carbon sink efficiency, and facilitates the achievement of carbon neutrality goals.
[Objective]Within the framework of the dual carbon target vision, addressing the scale effects of forest land changes and quantifying the carbon sequestration benefits at multiple watershed levels not only introduce a fresh perspective into forest land research but also aid in cording and optimizing the forest land pattern. That holds great significance in enhancing future regional carbon sequestration potential.[Methods]Focusing on Chongqing as the study area, we analyzed the spatiotemporal dynamic changes in forest land and carbon storage from 2000 to 2030 at the multi-watershed scale, utilizing PLUS model, landscape pattern indices, biomass expansion factor method and grey correlation degree. Furthermore, we explored the correlation between forest land pattern changes and carbon storage under natural development scenarios.[Results](1)Between 2000 and 2020,the forest area increased by 3404.55 km2,primarily due to the conversion of cultivated land. The forest landscape pattern in the first-grade watershed showed a tendency towards clustering and regularity, with a relatively reduced degree of fragmentation. There were distinct differences in the historical laws and future trends of forest landscape pattern changes in the secondary watershed’s “district and group”.(2)In the initial two decades, the carbon storage of forest land exhibited an increasing-decreasing trend, resulting in an overall increase. The Dongting Lake system in the first level basin witnessed the highest increase in carbon storage, and the high-value area of carbon storage increment in the seconde level basin shifted from north to south.(3)The total carbon storage is predicted to increase by 2030 which is strongly correlated with the irregular index. The scale effect leads to the spatial heterogeneity of landscape pattern change and the correlation degree between landscape pattern index and carbon storage in the primary and secondary basins.[Conclusion]The research outcome contribute to understanding the patterns of forest land changes from a cross-watershed scale perspective. This, in turn, provides a scientific foundation for the Ministry of Natural Resource or relevant forestry departments to formulate effective utilization and protection policies for forest land resources at different scales, It also supports the sustainable development of Chongqing, enhances carbon sink efficiency, and facilitates the achievement of carbon neutrality goals.
Abstract:
[Objective] To In order to better monitor and evaluate the ecological quality of hilly areas, it is necessary to construct a accurate remote sensing ecological index of middle and high vegetation areas, and explore the influencing factors of its ecological quality, so as to provide scientific support for the balance between development and ecology in Taojiang County. [Method] To address the saturation issue of the Normalized Difference Vegetation Index (NDVI) in densely vegetated areas, this study introduces the kernel Normalized Difference Vegetation Index (kNDVI) and integrates it with humidity, dryness, and heat factors to formulate a Modified Remote Sensing Ecology Index (MRSEI). Utilizing this index, the ecological environment quality and its temporal variation in Taojiang County from 2000 to 2021 were quantified. Additionally, a parameter optimized geographic detector model was employed to analyze the driving forces of six influencing factors, including vegetation coverage, precipitation, temperature, land use, altitude, and population density. [Result] (1) Compared with the RSEI model, the MRSEI model can effectively address the issue of NDVI saturation in areas with high vegetation cover, enabling a more precise monitoring of the ecological environment in Taojiang County; (2) The average RSEI values for the five periods from 2000 to 2021 in the study area were 0.77, 0.84, 0.83, 0.75 and 0.79, respectively, indicating a satisfactory performance in ecological environment quality with a trend of improvement-deterioration-improvement; (3) From the analysis of the factors influencing ecological environment quality, land use emerges as a key factor determinant in the study area. In the factor interactive detection analysis, the interaction between land use and elevation were strongest. [Conclusion] In summary, variation of the ecological environment quality in Taojiang County is primarily influenced by a combination of natural and anthropogenic factors. The research results can provide technical reference for carrying out effective ecological environment protection and restoration measures in Taojiang County.
[Objective] To In order to better monitor and evaluate the ecological quality of hilly areas, it is necessary to construct a accurate remote sensing ecological index of middle and high vegetation areas, and explore the influencing factors of its ecological quality, so as to provide scientific support for the balance between development and ecology in Taojiang County. [Method] To address the saturation issue of the Normalized Difference Vegetation Index (NDVI) in densely vegetated areas, this study introduces the kernel Normalized Difference Vegetation Index (kNDVI) and integrates it with humidity, dryness, and heat factors to formulate a Modified Remote Sensing Ecology Index (MRSEI). Utilizing this index, the ecological environment quality and its temporal variation in Taojiang County from 2000 to 2021 were quantified. Additionally, a parameter optimized geographic detector model was employed to analyze the driving forces of six influencing factors, including vegetation coverage, precipitation, temperature, land use, altitude, and population density. [Result] (1) Compared with the RSEI model, the MRSEI model can effectively address the issue of NDVI saturation in areas with high vegetation cover, enabling a more precise monitoring of the ecological environment in Taojiang County; (2) The average RSEI values for the five periods from 2000 to 2021 in the study area were 0.77, 0.84, 0.83, 0.75 and 0.79, respectively, indicating a satisfactory performance in ecological environment quality with a trend of improvement-deterioration-improvement; (3) From the analysis of the factors influencing ecological environment quality, land use emerges as a key factor determinant in the study area. In the factor interactive detection analysis, the interaction between land use and elevation were strongest. [Conclusion] In summary, variation of the ecological environment quality in Taojiang County is primarily influenced by a combination of natural and anthropogenic factors. The research results can provide technical reference for carrying out effective ecological environment protection and restoration measures in Taojiang County.
Abstract:
[Objective] In order to understand the effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after highway project disturbance in alpine wetland, we aim to provide theoretical reference basis for the screening of vegetation restoration model in alpine wetland, the management of soil erosion and the improvement of ecological environment. [Method] The three treatment slopes of natural succession, spraying grass planting and turf mulching and the original undisturbed control vegetation were taken as the research objects, and the soil physicochemical indexes and soil enzyme activities were measured to analyze their interrelationships and influencing factors. [Result] 1) All three restoration measures resulted in a significant increase (P<0.05) in soil pH and total potassium, and a significant decrease (P<0.05) in soil organic matter, total nitrogen, total phosphorus, and fine root biomass compared to the control; effective phosphorus increased and quick-acting potassium decreased compared to the control; the proportion of clayey silt particles in soil particles of the natural succession was not significantly different from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) in the spraying of grasses and turf mulch treatment; the turf mulch richness index did not differ significantly from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) under spraying of grasses and natural succession. The proportion of sticky powder particles in soil particles in the natural succession was not significantly different from that of the control, and the proportion of sticky powder particles in soil particles in the spraying and sodding treatments was significantly lower (P<0.05); the richness indices of sodding were not significantly different from that of the control, and those of spraying and sodding were significantly lower than that of the control (P<0.05), and the soil pH, organic matter, total nitrogen, quick-acting potassium, fine root biomass, and their richness indices in the sodding and sodding treatments were higher than those in the natural succession (P<0.05).2) Sprayed grass and turf replanting restored the four soil enzymes better than natural succession, and even catalase activity was restored to near control levels. 3)The correlation between the four enzyme activities and soil physicochemical properties was significant, and the urease activity was the most sensitive to soil physicochemical properties, which was able to evaluate the soil fertility of plateau wetland slope well. [Conclusion] Compared with natural succession, spraying grass and turf can effectively improve soil physicochemical properties and soil enzyme activity, and soil enzyme can be used as a sensitive indicator for evaluating soil fertility on slopes in plateau wetlands.
[Objective] In order to understand the effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after highway project disturbance in alpine wetland, we aim to provide theoretical reference basis for the screening of vegetation restoration model in alpine wetland, the management of soil erosion and the improvement of ecological environment. [Method] The three treatment slopes of natural succession, spraying grass planting and turf mulching and the original undisturbed control vegetation were taken as the research objects, and the soil physicochemical indexes and soil enzyme activities were measured to analyze their interrelationships and influencing factors. [Result] 1) All three restoration measures resulted in a significant increase (P<0.05) in soil pH and total potassium, and a significant decrease (P<0.05) in soil organic matter, total nitrogen, total phosphorus, and fine root biomass compared to the control; effective phosphorus increased and quick-acting potassium decreased compared to the control; the proportion of clayey silt particles in soil particles of the natural succession was not significantly different from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) in the spraying of grasses and turf mulch treatment; the turf mulch richness index did not differ significantly from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) under spraying of grasses and natural succession. The proportion of sticky powder particles in soil particles in the natural succession was not significantly different from that of the control, and the proportion of sticky powder particles in soil particles in the spraying and sodding treatments was significantly lower (P<0.05); the richness indices of sodding were not significantly different from that of the control, and those of spraying and sodding were significantly lower than that of the control (P<0.05), and the soil pH, organic matter, total nitrogen, quick-acting potassium, fine root biomass, and their richness indices in the sodding and sodding treatments were higher than those in the natural succession (P<0.05).2) Sprayed grass and turf replanting restored the four soil enzymes better than natural succession, and even catalase activity was restored to near control levels. 3)The correlation between the four enzyme activities and soil physicochemical properties was significant, and the urease activity was the most sensitive to soil physicochemical properties, which was able to evaluate the soil fertility of plateau wetland slope well. [Conclusion] Compared with natural succession, spraying grass and turf can effectively improve soil physicochemical properties and soil enzyme activity, and soil enzyme can be used as a sensitive indicator for evaluating soil fertility on slopes in plateau wetlands.
Abstract:
[Objective] This study explores the effects of long-term Caragana korshinskii (C. korshinskii) plantation on the stability of soil aggregates and erodibility on the loess hilly slopes, providing theoretical support for artificial vegetation construction and ecological restoration in the Loess Plateau region. [Methods] Grassy slope was used as a comparison, C. korshinskii plots with different plantation durations (15, 25, 35 years) along contour lines on slopes were selected as research subjects. The study analyzed the characteristics of changes in soil aggregate stability and erodibility due to long-term C. korshinskii plantation, as well as the main influencing factors. [Results] (1) The soil aggregate stability indicators, mean weight diameter (MWD), geometric mean diameter (GMD), and the content of aggregates >0.25 mm (WR0.25), generally showed a trend of 15-year C. korshinskii plantation > barren grassy land > 25-year C. korshinskii plantation > 35-year C. korshinskii plantation. In terms of slope position, the order was bottom slope > top slope > mid-slope > upper slope. Conversely, the soil erodibility K factor exhibited an opposite trend. (2) With the increase in the plantation duration of C. korshinskii compared to barren grassy land, soil aggregate stability indicators initially increased and then decreased, while the stability in the intervals of barren grassy strips continuously declined. The difference between the two became more pronounced after the plantation duration exceeded 15 years, especially at the bottom slope. (3) Soil organic carbon and slope position were the main factors influencing the soil aggregation stability and erodibility on the slope, explaining 38% and 4.1% of the variation, respectively, followed by planting duration and altitude. [Conclusion] Strip plantation of C. korshinskii on the loess hilly slopes affects the distribution of soil organic carbon, thereby influencing soil aggregate stability and erodibility. Plantation for less than 15 years contributes to the improvement of soil aggregate stability and the reduction of erodibility, but a reverse trend gradually emerges with more extended plantation, particularly at the bottom slope locations.
[Objective] This study explores the effects of long-term Caragana korshinskii (C. korshinskii) plantation on the stability of soil aggregates and erodibility on the loess hilly slopes, providing theoretical support for artificial vegetation construction and ecological restoration in the Loess Plateau region. [Methods] Grassy slope was used as a comparison, C. korshinskii plots with different plantation durations (15, 25, 35 years) along contour lines on slopes were selected as research subjects. The study analyzed the characteristics of changes in soil aggregate stability and erodibility due to long-term C. korshinskii plantation, as well as the main influencing factors. [Results] (1) The soil aggregate stability indicators, mean weight diameter (MWD), geometric mean diameter (GMD), and the content of aggregates >0.25 mm (WR0.25), generally showed a trend of 15-year C. korshinskii plantation > barren grassy land > 25-year C. korshinskii plantation > 35-year C. korshinskii plantation. In terms of slope position, the order was bottom slope > top slope > mid-slope > upper slope. Conversely, the soil erodibility K factor exhibited an opposite trend. (2) With the increase in the plantation duration of C. korshinskii compared to barren grassy land, soil aggregate stability indicators initially increased and then decreased, while the stability in the intervals of barren grassy strips continuously declined. The difference between the two became more pronounced after the plantation duration exceeded 15 years, especially at the bottom slope. (3) Soil organic carbon and slope position were the main factors influencing the soil aggregation stability and erodibility on the slope, explaining 38% and 4.1% of the variation, respectively, followed by planting duration and altitude. [Conclusion] Strip plantation of C. korshinskii on the loess hilly slopes affects the distribution of soil organic carbon, thereby influencing soil aggregate stability and erodibility. Plantation for less than 15 years contributes to the improvement of soil aggregate stability and the reduction of erodibility, but a reverse trend gradually emerges with more extended plantation, particularly at the bottom slope locations.
Abstract:
［Objective］To explore the effects of snow removal during freezing-thawing period on soil organic carbon components and carbon pool stability in Bayanbulak alpine wetland. ［Methods］A field experiment was conducted in September 2022, with two treatments: snow removal and natural snowfall. The samples were collected during the initial freezing period (November), freezing period (March), and thawing period (July) of the freezing-thawing period, and the soil water content (SWC), electrical conductivity (EC), pH value, soil organic carbon (SOC), very unstable organic carbon (F1), unstable organic carbon (F2), stable organic carbon (F3), and inert organic carbon (F4) were determined. ［Results］There were significant differences in the organic carbon content of F1 and F2 components after snow removal in the initial freezing period (P<0.05), compared with the natural snowfall, the organic carbon content of the two components decreased by 8.72% and 12.26%, respectively. There were significant differences in the organic carbon content of F3 components between different treatments in the freezing period (P<0.05), and the organic carbon content of F3 components decreased by 25.57% after snow removal. There were significant differences in the organic carbon content of F1, F2 and F3 in the thawing period (P<0.05), among which F1 and F3 decreased by 22.10% and 25.57%, respectively, and F2 increased by 34.92%, while there were no significant differences in other components. After snow removal, compared with the natural snowfall treatment, the carbon pool activity increased by 5.99%, 9.71% and 20.39% in the three periods, respectively.［Conclusion］The freeze-thaw cycle and snow removal had no significant effect on the organic carbon content and carbon pool stability, but the effect of snow removal on soil was greater than the freeze-thaw change. Snow removal led to the decrease of soil organic carbon content and the increase of soil organic carbon pool stability, which affected the original stable relationship between soil organic carbon components. With the freeze-thaw process, the soil organic carbon content showed a trend of first decrease and then increase, while the soil carbon pool stability showed a trend of first increase and then decrease.
［Objective］To explore the effects of snow removal during freezing-thawing period on soil organic carbon components and carbon pool stability in Bayanbulak alpine wetland. ［Methods］A field experiment was conducted in September 2022, with two treatments: snow removal and natural snowfall. The samples were collected during the initial freezing period (November), freezing period (March), and thawing period (July) of the freezing-thawing period, and the soil water content (SWC), electrical conductivity (EC), pH value, soil organic carbon (SOC), very unstable organic carbon (F1), unstable organic carbon (F2), stable organic carbon (F3), and inert organic carbon (F4) were determined. ［Results］There were significant differences in the organic carbon content of F1 and F2 components after snow removal in the initial freezing period (P<0.05), compared with the natural snowfall, the organic carbon content of the two components decreased by 8.72% and 12.26%, respectively. There were significant differences in the organic carbon content of F3 components between different treatments in the freezing period (P<0.05), and the organic carbon content of F3 components decreased by 25.57% after snow removal. There were significant differences in the organic carbon content of F1, F2 and F3 in the thawing period (P<0.05), among which F1 and F3 decreased by 22.10% and 25.57%, respectively, and F2 increased by 34.92%, while there were no significant differences in other components. After snow removal, compared with the natural snowfall treatment, the carbon pool activity increased by 5.99%, 9.71% and 20.39% in the three periods, respectively.［Conclusion］The freeze-thaw cycle and snow removal had no significant effect on the organic carbon content and carbon pool stability, but the effect of snow removal on soil was greater than the freeze-thaw change. Snow removal led to the decrease of soil organic carbon content and the increase of soil organic carbon pool stability, which affected the original stable relationship between soil organic carbon components. With the freeze-thaw process, the soil organic carbon content showed a trend of first decrease and then increase, while the soil carbon pool stability showed a trend of first increase and then decrease.
Abstract:
[Objective] A large number of red clay slopes exist in Guizhou Province, and soil erosion and shallow landslides are prominent problems. The use of herbaceous plants to protect red clay slopes is of great significance for shallow landslide management and soil and water conservation in Guizhou Province, but there are fewer related studies. [Methods] With red clay slope as the research object, Cynodon dactylon and Vetiver grass were selected as slope protection plants. The slope protection effect of the two herbaceous plants was investigated through planting test, root tensile test, straight shear test, and indoor simulated scouring test. [Results] ① Within 150 days of planting, both herbaceous plants grew steadily and the tensile strength of the root system continued to increase. From 30 to 150 days of growth, the maximum tensile strength of Cynodon dactylon increased from 0.84N to 8.59N, and that of Vetiver grass increased from 4.78N to 89.89N. ② Comparing the rootless soil at 120 days of growth, the cohesion of Cynodon dactylon root-soil complex increased by 91.1% and the angle of internal friction by 12.45%; the cohesion of Vetiver grass root-soil complex increased by 107.47% and the angle of internal friction by 12.74%. ③ Comparing the bare slope at 150 days of growth, the runoff rate of Cynodon dactylon slope decreased by 45.02% to 54.15%, the sediment yield rate decreased by 58.3% to 93.85%, and the 60-min cumulative sediment yield decreased by 81.02%; the runoff rate of Vetiver grass slope decreased by 35.46% to 46.48%, the sediment yield decreased rate by 46.8% to 89.44%, and the 60-min cumulative sediment yield decreased by 74.61%. [Conclusion] Both herbaceous plants have excellent soil consolidation and slope protection effects on red clay slopes, with Vetiver grass having a more pronounced effect on the increase in soil shear strength, and Cynodon dactylon having a more significant effect on soil and water conservation.
[Objective] A large number of red clay slopes exist in Guizhou Province, and soil erosion and shallow landslides are prominent problems. The use of herbaceous plants to protect red clay slopes is of great significance for shallow landslide management and soil and water conservation in Guizhou Province, but there are fewer related studies. [Methods] With red clay slope as the research object, Cynodon dactylon and Vetiver grass were selected as slope protection plants. The slope protection effect of the two herbaceous plants was investigated through planting test, root tensile test, straight shear test, and indoor simulated scouring test. [Results] ① Within 150 days of planting, both herbaceous plants grew steadily and the tensile strength of the root system continued to increase. From 30 to 150 days of growth, the maximum tensile strength of Cynodon dactylon increased from 0.84N to 8.59N, and that of Vetiver grass increased from 4.78N to 89.89N. ② Comparing the rootless soil at 120 days of growth, the cohesion of Cynodon dactylon root-soil complex increased by 91.1% and the angle of internal friction by 12.45%; the cohesion of Vetiver grass root-soil complex increased by 107.47% and the angle of internal friction by 12.74%. ③ Comparing the bare slope at 150 days of growth, the runoff rate of Cynodon dactylon slope decreased by 45.02% to 54.15%, the sediment yield rate decreased by 58.3% to 93.85%, and the 60-min cumulative sediment yield decreased by 81.02%; the runoff rate of Vetiver grass slope decreased by 35.46% to 46.48%, the sediment yield decreased rate by 46.8% to 89.44%, and the 60-min cumulative sediment yield decreased by 74.61%. [Conclusion] Both herbaceous plants have excellent soil consolidation and slope protection effects on red clay slopes, with Vetiver grass having a more pronounced effect on the increase in soil shear strength, and Cynodon dactylon having a more significant effect on soil and water conservation.
Abstract:
［Objective］This study aims to investigate the soil runoff characteristics on the southern slopes of the Taihang Mountains and explore the influencing factors. The goal is to provide scientific basis for soil erosion control and ecological environment protection in the southern foothills of the Taihang Mountains. ［Methods］The study focuses on the fish scale pits and natural barren slopes on the southern foothills of the Taihang Mountains. The runoff characteristics on the slopes under different vegetation types including herbs, shrubs, and trees were measured, and the influencing factors were analyzed. The geographic detector statistical method was used to quantify the individual and interactive effects of various factors on slope runoff. ［Results］The results indicate the following: (1) There was no significant difference in the average runoff depth between herb, shrub, and tree communities on the fish scale pits. However, the average runoff depth of the shrub and herb communities on the natural barren slopes was significantly greater than that of the tree community. Compared to the natural barren slopes, the average runoff depth decreased by 56.61%, 72.80%, and 39.58% in the herb, shrub, and tree communities on the fish scale pits, respectively. The average runoff depth showed a decreasing trend with increasing gravel content. The control effect of gravel coverage on slope runoff had a threshold, and the minimum slope runoff depth was observed when the gravel coverage ranged from 6% to 9%. (2) The single-factor influence of gravel coverage (0.31) was the highest on slope runoff in the southern foothills of the Taihang Mountains, followed by vegetation coverage (0.29). (3) The interaction of slope runoff influencing factors mostly exhibited nonlinear enhancement and dual-factor enhancement effects. The interaction between rainfall and non-rainfall factors showed nonlinear enhancement effects. ［Conclusion］The presence of a large amount of gravel contributes to the complexity of slope runoff processes in the southern foothills of the Taihang Mountains. Increasing vegetation coverage is an important measure to reduce slope runoff in this region.
［Objective］This study aims to investigate the soil runoff characteristics on the southern slopes of the Taihang Mountains and explore the influencing factors. The goal is to provide scientific basis for soil erosion control and ecological environment protection in the southern foothills of the Taihang Mountains. ［Methods］The study focuses on the fish scale pits and natural barren slopes on the southern foothills of the Taihang Mountains. The runoff characteristics on the slopes under different vegetation types including herbs, shrubs, and trees were measured, and the influencing factors were analyzed. The geographic detector statistical method was used to quantify the individual and interactive effects of various factors on slope runoff. ［Results］The results indicate the following: (1) There was no significant difference in the average runoff depth between herb, shrub, and tree communities on the fish scale pits. However, the average runoff depth of the shrub and herb communities on the natural barren slopes was significantly greater than that of the tree community. Compared to the natural barren slopes, the average runoff depth decreased by 56.61%, 72.80%, and 39.58% in the herb, shrub, and tree communities on the fish scale pits, respectively. The average runoff depth showed a decreasing trend with increasing gravel content. The control effect of gravel coverage on slope runoff had a threshold, and the minimum slope runoff depth was observed when the gravel coverage ranged from 6% to 9%. (2) The single-factor influence of gravel coverage (0.31) was the highest on slope runoff in the southern foothills of the Taihang Mountains, followed by vegetation coverage (0.29). (3) The interaction of slope runoff influencing factors mostly exhibited nonlinear enhancement and dual-factor enhancement effects. The interaction between rainfall and non-rainfall factors showed nonlinear enhancement effects. ［Conclusion］The presence of a large amount of gravel contributes to the complexity of slope runoff processes in the southern foothills of the Taihang Mountains. Increasing vegetation coverage is an important measure to reduce slope runoff in this region.
Abstract:
Abstract：[Objective] To support building a low-carbon agricultural model, promoting agricultural carbon reduction and high-quality regional agriculture development. [Methods] The estimation model of carbon emission from cultivated land and ArcGIS calculation were used to analyze the temporal and spatial characteristics of carbon emission from cultivated land in the urban belt along the Yellow River in Ningxia, and the unexpected output super-efficiency model (SBM) was used to evaluate the ecological efficiency of cultivated land. [Results] (1) The total carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia showed an overall downward trend from 2011 to 2020, and chemical fertilizer and agricultural diesel were the primary sources of carbon emission from cultivated land. (2) The carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia shows a spatial distribution pattern of high in the north-south and low in the middle. Pingluo County and Zhongning County are the largest cultivated land carbon emission cities. (3) The trend of carbon emission intensity of cultivated land in the urban belt along the Yellow River in Ningxia is similar to that of cultivated land. (4) The ecological efficiency of cultivated land use in the urban belt along the Yellow River in Ningxia fluctuates as a whole, and the ecological efficiency of cultivated land in the Litong area is low, so it is necessary to adjust the input factors in the agricultural production process. [Conclusion] To study the temporal and spatial evolution characteristics of carbon emission and ecological efficiency of cultivated land in the urban belt along the Yellow River in Ningxia and explore their key influencing factors. The relevant conclusions can provide a reference for the construction of low-carbon agriculture and accurate policy implementation in Ningxia.
Abstract：[Objective] To support building a low-carbon agricultural model, promoting agricultural carbon reduction and high-quality regional agriculture development. [Methods] The estimation model of carbon emission from cultivated land and ArcGIS calculation were used to analyze the temporal and spatial characteristics of carbon emission from cultivated land in the urban belt along the Yellow River in Ningxia, and the unexpected output super-efficiency model (SBM) was used to evaluate the ecological efficiency of cultivated land. [Results] (1) The total carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia showed an overall downward trend from 2011 to 2020, and chemical fertilizer and agricultural diesel were the primary sources of carbon emission from cultivated land. (2) The carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia shows a spatial distribution pattern of high in the north-south and low in the middle. Pingluo County and Zhongning County are the largest cultivated land carbon emission cities. (3) The trend of carbon emission intensity of cultivated land in the urban belt along the Yellow River in Ningxia is similar to that of cultivated land. (4) The ecological efficiency of cultivated land use in the urban belt along the Yellow River in Ningxia fluctuates as a whole, and the ecological efficiency of cultivated land in the Litong area is low, so it is necessary to adjust the input factors in the agricultural production process. [Conclusion] To study the temporal and spatial evolution characteristics of carbon emission and ecological efficiency of cultivated land in the urban belt along the Yellow River in Ningxia and explore their key influencing factors. The relevant conclusions can provide a reference for the construction of low-carbon agriculture and accurate policy implementation in Ningxia.
Abstract:
[Objective]This study aims to analyze the carbon emission characteristics and driving factors of agriculture and animal husbandry in Qinghai Province, and to provide theoretical and empirical evidence for Qinghai government on how to promote scientifically and orderly the green and low-carbon development of agriculture and animal husbandry.[Methods] Carbon emissions from agriculture and animal husbandry in Qinghai Province during 2000 to 2021 are calculated from consumption of agricultural materials, livestock and poultry breeding, and crop growth. The methods of LMDI and Tapio decoupling models are used to examine the driving factors and decoupling state of carbon emissions from agriculture and animal husbandry, and the future development tendency from 2022 to 2035 is predicted.[Results]①Carbon emissions from agriculture and animal husbandry in Qinghai Province shows a fluctuating upward trend during 2000 to 2021, with an average annual growth rate of 1.61%. Intestinal fermentation and manure management during livestock and poultry breeding are the main sources of carbon emissions, accounting for 94.94% per year.②The effect of the level of agricultural economic development and agricultural structure can increase the carbon emissions, with the annual contribution rates of 39.40% and 16.53%; The effect of agricultural production technology and agricultural labor force can inhibit the carbon emissions , with the annual contribution rates of -37.45% and -6.63%.③On the whole, the decoupling state between carbon emissions and economic growth of agricultural and animal husbandry in Qinghai Province is in weak decoupling. Agricultural production technology and agricultural labor force scale have weak decoupling efforts, while agricultural structure has no decoupling efforts.④From 2022 to 2035, the carbon emissions from agriculture and animal husbandry shows an increasing trend, with an average annual growth rate of 1.23%, and 0.38% lower than that from 2000 to 2021.[Conclusion]: This study contributes to call the attention of Qinghai government and relevant authorities to achieve low-carbon development in agriculture and animal husbandry. Some useful suggestions are put forward as follows: enhance the carbon sequestration capacity of farmland soil, reduce the intensity of intestinal methane emissions from livestock and poultry products, strengthen the leadership of carbon reduction and fixation technology in agriculture and animal husbandry, cultivate high-quality talents in agriculture and animal husbandry.
[Objective]This study aims to analyze the carbon emission characteristics and driving factors of agriculture and animal husbandry in Qinghai Province, and to provide theoretical and empirical evidence for Qinghai government on how to promote scientifically and orderly the green and low-carbon development of agriculture and animal husbandry.[Methods] Carbon emissions from agriculture and animal husbandry in Qinghai Province during 2000 to 2021 are calculated from consumption of agricultural materials, livestock and poultry breeding, and crop growth. The methods of LMDI and Tapio decoupling models are used to examine the driving factors and decoupling state of carbon emissions from agriculture and animal husbandry, and the future development tendency from 2022 to 2035 is predicted.[Results]①Carbon emissions from agriculture and animal husbandry in Qinghai Province shows a fluctuating upward trend during 2000 to 2021, with an average annual growth rate of 1.61%. Intestinal fermentation and manure management during livestock and poultry breeding are the main sources of carbon emissions, accounting for 94.94% per year.②The effect of the level of agricultural economic development and agricultural structure can increase the carbon emissions, with the annual contribution rates of 39.40% and 16.53%; The effect of agricultural production technology and agricultural labor force can inhibit the carbon emissions , with the annual contribution rates of -37.45% and -6.63%.③On the whole, the decoupling state between carbon emissions and economic growth of agricultural and animal husbandry in Qinghai Province is in weak decoupling. Agricultural production technology and agricultural labor force scale have weak decoupling efforts, while agricultural structure has no decoupling efforts.④From 2022 to 2035, the carbon emissions from agriculture and animal husbandry shows an increasing trend, with an average annual growth rate of 1.23%, and 0.38% lower than that from 2000 to 2021.[Conclusion]: This study contributes to call the attention of Qinghai government and relevant authorities to achieve low-carbon development in agriculture and animal husbandry. Some useful suggestions are put forward as follows: enhance the carbon sequestration capacity of farmland soil, reduce the intensity of intestinal methane emissions from livestock and poultry products, strengthen the leadership of carbon reduction and fixation technology in agriculture and animal husbandry, cultivate high-quality talents in agriculture and animal husbandry.
WANG Jingzheng, ZHAO Chuanchuan, WANG Yuqin, XIE Linghua, WANG Yuqin, WANG Jiayi, ZHANG Sha, JIA Dongjin
Abstract:
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott''s second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott''s second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
Abstract:
[Purpose] The proposal of the dual carbon target has put forward higher requirements for the development of agriculture in China. This study takes the Beijing Tianjin Hebei region as the research object, divides the region into six major agricultural regions based on agricultural carbon emissions, and proposes corresponding emission reduction optimization paths, aiming to provide policy recommendations for the development of low-carbon agriculture in the Beijing Tianjin Hebei region Method: This study calculated agricultural carbon emissions based on the IPCC guidelines, and used trend analysis to study the linear changes in agricultural carbon emissions in the Beijing Tianjin Hebei region. ArcGIS breakpoint analysis and kernel density method were used to analyze the spatial evolution trends of the six major agricultural regions in the Beijing Tianjin Hebei region The study found that, in terms of time, the overall carbon emissions and carbon intensity of agriculture in the Beijing Tianjin Hebei region have shown a downward trend, especially the carbon emission intensity, which has been rapidly decreasing since 2005. Compared with the whole country, although the proportion of total agricultural carbon emissions is small, the carbon emission intensity is higher than the national level, with the highest carbon emission levels in the Bashang Agricultural Zone and the Jinan Agricultural Zone. From a spatial perspective, the northern part of the Bashang Agricultural Area, far from Beijing and Tianjin, as well as some counties in the Central Plains and Southern Hebei Agricultural Areas, have higher carbon emission intensity. However, the suburban agricultural area of Beijing and Tianjin, as well as the southern part of the adjacent Bashang Agricultural Area, maintain a light and low emission state. In addition, according to the results of nuclear density analysis, the overall carbon emission intensity of the six major agricultural regions is decreasing, with a greater degree of internal differentiation in carbon emission intensity between the Beijing Tianjin suburban agricultural region and the Hebei Central Plain agricultural region Conclusion: Based on the research results, an optimization path for carbon reduction in the Beijing Tianjin Hebei region is proposed from four aspects: agricultural positioning, resource sharing, carbon reduction and sink enhancement, and cross industry cooperation.
[Purpose] The proposal of the dual carbon target has put forward higher requirements for the development of agriculture in China. This study takes the Beijing Tianjin Hebei region as the research object, divides the region into six major agricultural regions based on agricultural carbon emissions, and proposes corresponding emission reduction optimization paths, aiming to provide policy recommendations for the development of low-carbon agriculture in the Beijing Tianjin Hebei region Method: This study calculated agricultural carbon emissions based on the IPCC guidelines, and used trend analysis to study the linear changes in agricultural carbon emissions in the Beijing Tianjin Hebei region. ArcGIS breakpoint analysis and kernel density method were used to analyze the spatial evolution trends of the six major agricultural regions in the Beijing Tianjin Hebei region The study found that, in terms of time, the overall carbon emissions and carbon intensity of agriculture in the Beijing Tianjin Hebei region have shown a downward trend, especially the carbon emission intensity, which has been rapidly decreasing since 2005. Compared with the whole country, although the proportion of total agricultural carbon emissions is small, the carbon emission intensity is higher than the national level, with the highest carbon emission levels in the Bashang Agricultural Zone and the Jinan Agricultural Zone. From a spatial perspective, the northern part of the Bashang Agricultural Area, far from Beijing and Tianjin, as well as some counties in the Central Plains and Southern Hebei Agricultural Areas, have higher carbon emission intensity. However, the suburban agricultural area of Beijing and Tianjin, as well as the southern part of the adjacent Bashang Agricultural Area, maintain a light and low emission state. In addition, according to the results of nuclear density analysis, the overall carbon emission intensity of the six major agricultural regions is decreasing, with a greater degree of internal differentiation in carbon emission intensity between the Beijing Tianjin suburban agricultural region and the Hebei Central Plain agricultural region Conclusion: Based on the research results, an optimization path for carbon reduction in the Beijing Tianjin Hebei region is proposed from four aspects: agricultural positioning, resource sharing, carbon reduction and sink enhancement, and cross industry cooperation.
Abstract:
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
Abstract:
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:
[Objective]The morphological characteristics and influencing factors of gully head in the mollisols farmland area were studied to provide basic data and theoretical support for gully head were investigated in the controlling gully erosion in the mollisols farmland area. [Methods]Taking the gully head in Hainan town small field, and the active state of gully watershed of Hailun as the research object, the morphological characteristics, soil
[Objective]The morphological characteristics and influencing factors of gully head in the mollisols farmland area were studied to provide basic data and theoretical support for gully head were investigated in the controlling gully erosion in the mollisols farmland area. [Methods]Taking the gully head in Hainan town small field, and the active state of gully watershed of Hailun as the research object, the morphological characteristics, soil
Abstract:
Abstract: The eastern foothills of Helan Mountain is a wonderful wine grape producing area in China. Exploring the carbon sequestration potential of the cultivated vineyards in the desert steppe area is crucial for achieving China's dual carbon goals in the region. To quantify soil carbon storage characteristics in grape plantations, this study focused on a typical vineyard of Xinhuibin, conducting a sampling investigation and analyzing soil organic carbon at the vineyard scale, examining its content, density, and composition. The results indicated that （1）in the 0-100 cm soil layer of the vineyard, the average soil organic carbon content was 4.65 g/kg, and the density was 64.5 t/hm2. Despite the low soil organic matter content and nutrient scarcity, it still constituted the main component of the vineyard's carbon pool. （2）Vertically, the soil organic carbon content decreased with depth, showing a significant difference between the 0-40 cm surface layer and the 40-100 cm deeper layer. The enrichment coefficient of organic carbon in the surface soil exceeded 1, indicating its enhanced ability to retain organic carbon. （3）Within the vineyard, soil organic carbon content exhibited spatial heterogeneity. This spatial heterogeneity, especially in the surface soil, was influenced by varied reclamation activities, including different grape varieties and fertilization practices across plots. The spatial heterogeneity of organic carbon in deep soil was determined by the formation of the original soil.（4）The ratio of active, neutral, and inert soil organic carbon components was approximately 1:2:5. This indicates a relatively high proportion of inert components, signifying a low active carbon pool with strong stability. While the inert organic carbon content governs the level of total organic carbon, variations in neutral organic carbon content also influence both total organic carbon and total carbon levels. These research findings provide valuable insights into the mechanisms of carbon sink formation and the potential for carbon sequestration in vineyards in arid regions.
Abstract: The eastern foothills of Helan Mountain is a wonderful wine grape producing area in China. Exploring the carbon sequestration potential of the cultivated vineyards in the desert steppe area is crucial for achieving China's dual carbon goals in the region. To quantify soil carbon storage characteristics in grape plantations, this study focused on a typical vineyard of Xinhuibin, conducting a sampling investigation and analyzing soil organic carbon at the vineyard scale, examining its content, density, and composition. The results indicated that （1）in the 0-100 cm soil layer of the vineyard, the average soil organic carbon content was 4.65 g/kg, and the density was 64.5 t/hm2. Despite the low soil organic matter content and nutrient scarcity, it still constituted the main component of the vineyard's carbon pool. （2）Vertically, the soil organic carbon content decreased with depth, showing a significant difference between the 0-40 cm surface layer and the 40-100 cm deeper layer. The enrichment coefficient of organic carbon in the surface soil exceeded 1, indicating its enhanced ability to retain organic carbon. （3）Within the vineyard, soil organic carbon content exhibited spatial heterogeneity. This spatial heterogeneity, especially in the surface soil, was influenced by varied reclamation activities, including different grape varieties and fertilization practices across plots. The spatial heterogeneity of organic carbon in deep soil was determined by the formation of the original soil.（4）The ratio of active, neutral, and inert soil organic carbon components was approximately 1:2:5. This indicates a relatively high proportion of inert components, signifying a low active carbon pool with strong stability. While the inert organic carbon content governs the level of total organic carbon, variations in neutral organic carbon content also influence both total organic carbon and total carbon levels. These research findings provide valuable insights into the mechanisms of carbon sink formation and the potential for carbon sequestration in vineyards in arid regions.
Abstract:
[Objective] In the construction of high-standard farmland, it is essential to consider carbon emissions and absorption in the agricultural production process while ensuring food security, in order to achieve China"s goal of carbon neutrality and contribute to the development of a strong agricultural sector.[Methods] This study measures the profit and loss of farmland in 60 cities within the Yellow River Basin from the perspective of food security, establishes a standard for farmland ecological compensation based on opportunity cost method, calculates carbon emissions from agricultural resources used in production and crop growth across these cities, estimates total carbon absorption through photosynthesis during crop growth, and determines the net carbon sink of farmland in this region by considering both sources and sinks. The average carbon trading price in 2021 serves as the compensation standard for calculating regional farmland ecological compensation from a "dual-carbon" perspective. Finally, by calculating farmland ecological compensation amounts separately under perspectives of food security and "double-carbon", we obtain comprehensive figures for dual-perspective ecological compensation within the Yellow River basin.[Results] Results indicate that most cities along Qinghai and Henan provinces where Yellow River flows accept certain levels of compensation.[Conclusion] Provincial capitals such as Xi"an, Zhengzhou, and Taiyuan need to pay higher amounts due to their significant urbanization level, industrialization progress, and robust economic development. These findings highlight a more pronounced conflict between local farmland security on one hand and food/ecological security on another.
Keywords:Yellow River Basin; Farmland ecological compensation; Food security;Carbon source；Carbon sink
[Objective] In the construction of high-standard farmland, it is essential to consider carbon emissions and absorption in the agricultural production process while ensuring food security, in order to achieve China"s goal of carbon neutrality and contribute to the development of a strong agricultural sector.[Methods] This study measures the profit and loss of farmland in 60 cities within the Yellow River Basin from the perspective of food security, establishes a standard for farmland ecological compensation based on opportunity cost method, calculates carbon emissions from agricultural resources used in production and crop growth across these cities, estimates total carbon absorption through photosynthesis during crop growth, and determines the net carbon sink of farmland in this region by considering both sources and sinks. The average carbon trading price in 2021 serves as the compensation standard for calculating regional farmland ecological compensation from a "dual-carbon" perspective. Finally, by calculating farmland ecological compensation amounts separately under perspectives of food security and "double-carbon", we obtain comprehensive figures for dual-perspective ecological compensation within the Yellow River basin.[Results] Results indicate that most cities along Qinghai and Henan provinces where Yellow River flows accept certain levels of compensation.[Conclusion] Provincial capitals such as Xi"an, Zhengzhou, and Taiyuan need to pay higher amounts due to their significant urbanization level, industrialization progress, and robust economic development. These findings highlight a more pronounced conflict between local farmland security on one hand and food/ecological security on another.
Keywords:Yellow River Basin; Farmland ecological compensation; Food security;Carbon source；Carbon sink
Abstract:
[Objective] In order to investigate the rainstorms and floods process and the soil erosion caused by rainstorms in small watershed, it is urgent to carry out the investigation of rainstorms and floods process and soil and water conservation, so as to provide scientific support for the next soil and water conservation decision. [Methods] The flood marks were measured and investigated in Huangmi East Ditch and Liangjiazhuang West Ditch by field investigation method, and the flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm flood to small watershed. [Results]① The rainfall lasted for a long time and was strong. The cumulative rainfall in Liangjiazhuang West Ditch Valley and Huangmi East Ditch Valley reached 1008.5mm and 613.6mm, respectively. According to the flood mark survey, the peak discharge modulus of Huangmi East Ditch and Liangjiazhuang West Ditch watershed are 10.80m3/s·km2 and 36.07m3/s·km2 respectively. Slope and soil and water conservation measures are the main factors affecting flood peak discharge. Larger slope will increase flood peak discharge, and perfect soil and water conservation measures can play an effective role in peak reduction. (3) The investigated small watershed is located in the upper reaches of 泜 river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watershed is larger than that of the downstream hydrology station. (4) The erosion situation of Liangjiazhuang West Ditch is more serious than that of Huangmi East Ditch, mainly because the area proportion of orchards, terraces and check dam in Huangmi East Ditch is larger than that of Huangmi West Ditch, the average slope of Huangmi East Ditch is smaller than that of Liangjiazhuang West Ditch, and the peak duration of rainfall at Liangjiazhuang rain measuring station is longer. [Conclusion] It is necessary and effective to implement soil and water conservation measures, and to further improve the construction of terrace and terrace valley. Good soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon.
[Objective] In order to investigate the rainstorms and floods process and the soil erosion caused by rainstorms in small watershed, it is urgent to carry out the investigation of rainstorms and floods process and soil and water conservation, so as to provide scientific support for the next soil and water conservation decision. [Methods] The flood marks were measured and investigated in Huangmi East Ditch and Liangjiazhuang West Ditch by field investigation method, and the flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm flood to small watershed. [Results]① The rainfall lasted for a long time and was strong. The cumulative rainfall in Liangjiazhuang West Ditch Valley and Huangmi East Ditch Valley reached 1008.5mm and 613.6mm, respectively. According to the flood mark survey, the peak discharge modulus of Huangmi East Ditch and Liangjiazhuang West Ditch watershed are 10.80m3/s·km2 and 36.07m3/s·km2 respectively. Slope and soil and water conservation measures are the main factors affecting flood peak discharge. Larger slope will increase flood peak discharge, and perfect soil and water conservation measures can play an effective role in peak reduction. (3) The investigated small watershed is located in the upper reaches of 泜 river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watershed is larger than that of the downstream hydrology station. (4) The erosion situation of Liangjiazhuang West Ditch is more serious than that of Huangmi East Ditch, mainly because the area proportion of orchards, terraces and check dam in Huangmi East Ditch is larger than that of Huangmi West Ditch, the average slope of Huangmi East Ditch is smaller than that of Liangjiazhuang West Ditch, and the peak duration of rainfall at Liangjiazhuang rain measuring station is longer. [Conclusion] It is necessary and effective to implement soil and water conservation measures, and to further improve the construction of terrace and terrace valley. Good soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon.
Abstract:
[Objective] Weathering degree and provenance of Pisha Sandstone were studied aiming to provide a basic theoretical basis for further research on Pisha Sandstone and prevention and control of soil erosion.[Methods] Taking the Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia as the research object, through field investigation and experimental research including major element, trace element and rare earth element geochemical characteristics, the Chemical Alteration Index (CIA), Plagioclase Alteration Index (PIA), ratios of light to heavy rare earth element (LREE/HREE) and related trace and rare earth element relationships of Pisha Sandstone were analyzed.[Results] ① Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar is mainly composed of SiO2 and Al2O3, with most of the major elements having lower content than the average upper crust (UCC); The geochemical classification diagram shows that Pisha Sandstone consists of shale, feldspar sandstone and lithic sandstone; The CIA value of Pisha Sandstone ranges from 64.95 to 86.57, with an average value of 77.46. This is consistent with the characteristics of the Pisha Sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering.② The trace element contents in siltstone and mudstone are higher than that in sandstone, with the highest content of Ba followed by Zr; The paleotemperature for the formation of Pisha Sandstone is 10.67 ℃~22.78 ℃, with an average value of 17.68 ℃ and the PIA value of Pisha Sandstone is 70.48~97.13, with an average of 89.76.③ The rare earth element distribution pattern of Pisha Sandstone is consistent with UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies; The total rare earth (∑REE), ratio of light rare earth to heavy rare earth (LREE/HREE) and (La/Yb)N values of siltstone and mudstone are all higher than those of sandstone. The differentiation is mainly due to the attraction of most of trace elements released by rock weathering during epigenetic processes by clay minerals or due to hydraulic sorting.[Conclusion] The Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia is a set of terrestrial clastic sedimentary rock with low compositional maturity and sorting degree, and the source area had experienced moderate to strong chemical weathering; The formation of Pisha Sandstone was under arid to semi-humid conditions; The Pisha Sandstone rare earth element distribution pattern, combined with the discrimination diagram of major and trace elements, indicates that the studied Pisha Sandstone from Yan'an Formation originated from the Hercynian-Indosinian granites in Yinshan-Daqingshan area to the northern Ordos Basin.
[Objective] Weathering degree and provenance of Pisha Sandstone were studied aiming to provide a basic theoretical basis for further research on Pisha Sandstone and prevention and control of soil erosion.[Methods] Taking the Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia as the research object, through field investigation and experimental research including major element, trace element and rare earth element geochemical characteristics, the Chemical Alteration Index (CIA), Plagioclase Alteration Index (PIA), ratios of light to heavy rare earth element (LREE/HREE) and related trace and rare earth element relationships of Pisha Sandstone were analyzed.[Results] ① Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar is mainly composed of SiO2 and Al2O3, with most of the major elements having lower content than the average upper crust (UCC); The geochemical classification diagram shows that Pisha Sandstone consists of shale, feldspar sandstone and lithic sandstone; The CIA value of Pisha Sandstone ranges from 64.95 to 86.57, with an average value of 77.46. This is consistent with the characteristics of the Pisha Sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering.② The trace element contents in siltstone and mudstone are higher than that in sandstone, with the highest content of Ba followed by Zr; The paleotemperature for the formation of Pisha Sandstone is 10.67 ℃~22.78 ℃, with an average value of 17.68 ℃ and the PIA value of Pisha Sandstone is 70.48~97.13, with an average of 89.76.③ The rare earth element distribution pattern of Pisha Sandstone is consistent with UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies; The total rare earth (∑REE), ratio of light rare earth to heavy rare earth (LREE/HREE) and (La/Yb)N values of siltstone and mudstone are all higher than those of sandstone. The differentiation is mainly due to the attraction of most of trace elements released by rock weathering during epigenetic processes by clay minerals or due to hydraulic sorting.[Conclusion] The Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia is a set of terrestrial clastic sedimentary rock with low compositional maturity and sorting degree, and the source area had experienced moderate to strong chemical weathering; The formation of Pisha Sandstone was under arid to semi-humid conditions; The Pisha Sandstone rare earth element distribution pattern, combined with the discrimination diagram of major and trace elements, indicates that the studied Pisha Sandstone from Yan'an Formation originated from the Hercynian-Indosinian granites in Yinshan-Daqingshan area to the northern Ordos Basin.
Abstract:
[Objective] The coal mining process also causes a series of ecological and environmental problems such as the reduction of biodiversity, the destruction of soil structure and the loss of nutrients. The severe disturbance to the soil structure in the mining area results in the exposure of organic carbon protected by soil aggregates, which is de-composed and mineralized by soil microorganisms, resulting in the loss of soil organic carbon. Vegetation recon-struction in disturbed open pit dump is considered to be an effective measure to improve soil structure and increase biodiversity. In recent years, microbial restoration technology (arbuscular mycorrhizal fungi) has been widely used in ecological restoration of mining areas, and has achieved obvious ecological improvement effect. In addition, exogenous substances such as weathered coal and green fertilizer are also considered to have a positive role in soil improvement. However, the effect of arbuscular mycorrhizal fungi combined with weathering coal and green fertilizer on vegetation growth and soil improvement is still unclear. [Methods] Therefore, based on the sea buckthorns demonstration base in the open pit of Hedaigou, Inner Mongolia, this study analyzed the effects of the combined action of fertilizer modes such as arbuscular mycorrhizal fungi (AMF) and other factors (weathered coal and green fertilizer) on the stability of soil aggregates and organic carbon recovery in the early vegetation resto-ration area of the open pit dump by investigating vegetation populations and collecting soil aggregate samples. [Result] The results showed that under the six treatment modes, the experimental group inoculated with AMF, applied green fertilizer and added weathered coal (sand and green wind) had the best effect on the improvement of understory vegetation diversity, and the diversity index was significantly improved compared with the control treatment. The experimental group inoculated with AMF and applied with green fertilizer (sand green) had the most significant effect on the development and stability of aggregates. The crushing rate of the experimental group was significantly lower than that of the control group, while the mean diameter of aggregate weight and geometric mean diameter were significantly higher than that of the control group. The analysis of the effect of organic carbon and total nitrogen in aggregates showed that the organic carbon and total nitrogen in aggregates treated with sand green were significantly higher than those in the experimental group inoculated only with AMF (sand grafting). [Con-clusion]:Overall, these results evaluated the effects of weathering coal, green fertilizer and AMF inoculation on improving vegetation diversity, aggregate stability and aggregate organic carbon recovery in field trials, and had important reference significance for optimizing artificial ecological restoration strategies in open-pit mines and accelerating soil carbon pool recovery.
[Objective] The coal mining process also causes a series of ecological and environmental problems such as the reduction of biodiversity, the destruction of soil structure and the loss of nutrients. The severe disturbance to the soil structure in the mining area results in the exposure of organic carbon protected by soil aggregates, which is de-composed and mineralized by soil microorganisms, resulting in the loss of soil organic carbon. Vegetation recon-struction in disturbed open pit dump is considered to be an effective measure to improve soil structure and increase biodiversity. In recent years, microbial restoration technology (arbuscular mycorrhizal fungi) has been widely used in ecological restoration of mining areas, and has achieved obvious ecological improvement effect. In addition, exogenous substances such as weathered coal and green fertilizer are also considered to have a positive role in soil improvement. However, the effect of arbuscular mycorrhizal fungi combined with weathering coal and green fertilizer on vegetation growth and soil improvement is still unclear. [Methods] Therefore, based on the sea buckthorns demonstration base in the open pit of Hedaigou, Inner Mongolia, this study analyzed the effects of the combined action of fertilizer modes such as arbuscular mycorrhizal fungi (AMF) and other factors (weathered coal and green fertilizer) on the stability of soil aggregates and organic carbon recovery in the early vegetation resto-ration area of the open pit dump by investigating vegetation populations and collecting soil aggregate samples. [Result] The results showed that under the six treatment modes, the experimental group inoculated with AMF, applied green fertilizer and added weathered coal (sand and green wind) had the best effect on the improvement of understory vegetation diversity, and the diversity index was significantly improved compared with the control treatment. The experimental group inoculated with AMF and applied with green fertilizer (sand green) had the most significant effect on the development and stability of aggregates. The crushing rate of the experimental group was significantly lower than that of the control group, while the mean diameter of aggregate weight and geometric mean diameter were significantly higher than that of the control group. The analysis of the effect of organic carbon and total nitrogen in aggregates showed that the organic carbon and total nitrogen in aggregates treated with sand green were significantly higher than those in the experimental group inoculated only with AMF (sand grafting). [Con-clusion]:Overall, these results evaluated the effects of weathering coal, green fertilizer and AMF inoculation on improving vegetation diversity, aggregate stability and aggregate organic carbon recovery in field trials, and had important reference significance for optimizing artificial ecological restoration strategies in open-pit mines and accelerating soil carbon pool recovery.
Abstract:
[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.
[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.
Abstract:
[Objective] changes in land use and carbon storage in the Maowei Sea were analyzed to provide a scientific basis for increasing its carbon sink and improving ecological value. [Methods] In this study, the remote sensing image data of the Maowei Sea in 2009, 2015 and 2021 were used for interpretation and acquisition by using supervised classification method. Based on the ArcGIS and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the study analyzed the spatiotemporal change of the land use and carbon storage in the Maowei Sea. [Results] The results show that: ①The land types in the Maowei Sea mainly showed the distribution characteristics of "large settlement, small miscellaneous areas", the area of cultivated land, shallow sea waters and fishery breeding areas decreased, and the area of mangrove wetlands, building land, forest grassland and silty tidal flats increased in 2009-2021. ②The carbon storage showed a trend of decline and then increase, the net carbon sequestration and its net present value in the Maowei Sea was increased by -110500 tons, 37700 tons, -72900 tons and -137 million, 47 million, -90 million respectively in 2009-2015, 2015-2021 and 2009-2021. ③The transformation mainly from high carbon sequestration land use types such as fishery breeding areas and forest and grasslands to low carbon sequestration type such as building land in the Maowei Sea in 2009-2021, the largest carbon storage loss caused by the conversion to building land, reaching 285100 tons, and the additional carbon storage increased by the fishery breeding area reached 180,800 tons. [Conclusion] accelerating the transformation and upgrading of farming methods, enhancing the proliferation of mangrove forests in terrestrial and aquatic forested areas and accelerating the construction of forest city in the Maowei Sea to promote its carbon sequestration and sustainable development.
[Objective] changes in land use and carbon storage in the Maowei Sea were analyzed to provide a scientific basis for increasing its carbon sink and improving ecological value. [Methods] In this study, the remote sensing image data of the Maowei Sea in 2009, 2015 and 2021 were used for interpretation and acquisition by using supervised classification method. Based on the ArcGIS and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the study analyzed the spatiotemporal change of the land use and carbon storage in the Maowei Sea. [Results] The results show that: ①The land types in the Maowei Sea mainly showed the distribution characteristics of "large settlement, small miscellaneous areas", the area of cultivated land, shallow sea waters and fishery breeding areas decreased, and the area of mangrove wetlands, building land, forest grassland and silty tidal flats increased in 2009-2021. ②The carbon storage showed a trend of decline and then increase, the net carbon sequestration and its net present value in the Maowei Sea was increased by -110500 tons, 37700 tons, -72900 tons and -137 million, 47 million, -90 million respectively in 2009-2015, 2015-2021 and 2009-2021. ③The transformation mainly from high carbon sequestration land use types such as fishery breeding areas and forest and grasslands to low carbon sequestration type such as building land in the Maowei Sea in 2009-2021, the largest carbon storage loss caused by the conversion to building land, reaching 285100 tons, and the additional carbon storage increased by the fishery breeding area reached 180,800 tons. [Conclusion] accelerating the transformation and upgrading of farming methods, enhancing the proliferation of mangrove forests in terrestrial and aquatic forested areas and accelerating the construction of forest city in the Maowei Sea to promote its carbon sequestration and sustainable development.
Abstract:
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
Abstract:
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract:
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
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[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
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[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
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[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
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[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
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[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
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[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
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[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
Abstract:
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
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[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
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[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
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[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
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[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
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[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
Abstract:
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
Abstract:
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
Abstract:
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
Abstract:
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
Abstract:
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
Abstract:
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
Abstract:
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
Abstract:
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
Abstract:
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
Abstract:
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
Abstract:
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
Abstract:
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
Abstract:
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
YANG Cuihong, LI Yong, WANG Xu, CHEN Tingting, GUO Hao, YANG Yijiang, WU Zongmeng, ZHOU Xiaoqi, HUANG Zhigang
Abstract:
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
Abstract:
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
Abstract:
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
Display Method:
2023,43(4):238-247, DOI: 10.13961/j.cnki.stbctb.20230508.007
Abstract:
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
2023,43(4):154-161,210, DOI: 10.13961/j.cnki.stbctb.2023.04.019
Abstract:
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
2012(5):8-12, DOI: 10.13961/j.cnki.stbctb.2012.05.011
Abstract:
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
2022,42(2):264-274, DOI: 10.13961/j.cnki.stbctb.2022.02.036
Abstract:
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
2023,43(4):220-228,326, DOI: 10.13961/j.cnki.stbctb.2023.04.027
Abstract:
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
2006(3):1-5, DOI: 10.13961/j.cnki.stbctb.2006.03.002
Abstract:
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
2009(1):62-65, DOI: 10.13961/j.cnki.stbctb.2009.01.027
Abstract:
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
2022,42(2):210-218, DOI: 10.13961/j.cnki.stbctb.20220124.001
Abstract:
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
2019,39(5):194-203, DOI: 10.13961/j.cnki.stbctb.2019.05.027
Abstract:
[Objective] This study aims to explore the regional water stress state and their causes and provides a theoretical basis for the development and allocation of rational water resources.[Methods] A three-dimensional water footprint model was built to analyze the sustainability of water resources by using the sustainability index of water resource. The logarithmic mean divisia index (LMDI) factor decomposition model was also applied to quantitatively analyze the structural, technological, economic, and population effects on water resources in Anhui Province from 2007 to 2016.[Results] ① From 2007 to 2016, the water footprint of Anhui Province, in which the internal water footprints accounted for 97.88% to 98.73%, at first increased and then decreased. The consumption of water by agriculture among the internal water footprints was the highest and showed the same variation as the overall water footprint. In 2016, the per capita agricultural water use in Anhui Province decreased from north to south, meanwhile, the Yangtze River basin accounted for the highest proportion in the other types of water footprint. ② During 2007-2016, the footprint depth of the Anhui Province fluctuated within 2~4 and eventually declined from north to south. The results indicated that the overall sustainable use of water resources in Anhui Province increased from 2007 to 2016. ③ The driving factors of the water footprint in Anhui Province showed that the technical effect was a reverse driving, and the economic effect contributed the most to the positive driving.[Conclusion] The three-dimensional water footprint model used in this study can be a helpful tool to better reflect the actual situation of the water footprint in Anhui Province. Although of the use of water resources generally increased, optimizing the structure of the water resources utilization and accelerating improvements in the efficiency of water resource usage is necessary to alleviate the pressure on water resources resulting from economic development and population growth.
[Objective] This study aims to explore the regional water stress state and their causes and provides a theoretical basis for the development and allocation of rational water resources.[Methods] A three-dimensional water footprint model was built to analyze the sustainability of water resources by using the sustainability index of water resource. The logarithmic mean divisia index (LMDI) factor decomposition model was also applied to quantitatively analyze the structural, technological, economic, and population effects on water resources in Anhui Province from 2007 to 2016.[Results] ① From 2007 to 2016, the water footprint of Anhui Province, in which the internal water footprints accounted for 97.88% to 98.73%, at first increased and then decreased. The consumption of water by agriculture among the internal water footprints was the highest and showed the same variation as the overall water footprint. In 2016, the per capita agricultural water use in Anhui Province decreased from north to south, meanwhile, the Yangtze River basin accounted for the highest proportion in the other types of water footprint. ② During 2007-2016, the footprint depth of the Anhui Province fluctuated within 2~4 and eventually declined from north to south. The results indicated that the overall sustainable use of water resources in Anhui Province increased from 2007 to 2016. ③ The driving factors of the water footprint in Anhui Province showed that the technical effect was a reverse driving, and the economic effect contributed the most to the positive driving.[Conclusion] The three-dimensional water footprint model used in this study can be a helpful tool to better reflect the actual situation of the water footprint in Anhui Province. Although of the use of water resources generally increased, optimizing the structure of the water resources utilization and accelerating improvements in the efficiency of water resource usage is necessary to alleviate the pressure on water resources resulting from economic development and population growth.
2002(4):50-53, DOI: 10.13961/j.cnki.stbctb.2002.04.013
Abstract:
对青藏铁路格尔木—拉萨段的生态环境本底状况作了全面地分析,指出建于世界上最高、最大的高原面上的青藏铁路沿线的生态环境具有无以比拟的特殊性、敏感性、脆弱性和生态景观的差异性,如果施工期间未能采取行之有效的环保措施,那么巨大的土石开挖量、堆积量和工程迹地量定会对青藏高原的生态环境造成严重的负面影响。提出了一系列的环保措施,以期对铁路建设单位有所帮助,将对青藏高原生态环境造成的负面影响减少到最小,使生态环境恢复到最好
对青藏铁路格尔木—拉萨段的生态环境本底状况作了全面地分析,指出建于世界上最高、最大的高原面上的青藏铁路沿线的生态环境具有无以比拟的特殊性、敏感性、脆弱性和生态景观的差异性,如果施工期间未能采取行之有效的环保措施,那么巨大的土石开挖量、堆积量和工程迹地量定会对青藏高原的生态环境造成严重的负面影响。提出了一系列的环保措施,以期对铁路建设单位有所帮助,将对青藏高原生态环境造成的负面影响减少到最小,使生态环境恢复到最好
2023,43(2):43-49,59, DOI: 10.13961/j.cnki.stbctb.20230423.001
Abstract:
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
Abstract:
Based on the statistic data of crop yield,planting area,effective irrigation area,fertilizer usage and agricultural machinery power of Hebei Province from 1989 to 2008,the carbon source and sink of the farmland ecosystems in Hebei Province were estimated.Furthermore,the temporal and spatial variations and the influencing factors of carbon source and sink were analyzed.The results showed that the total carbon sequestration and emission of the farmland ecosystems in Hebei Province showed a gradually rising process in the last 20 years,and more carbon was sequestrated than emitted.Overall,the farmland ecosystem of Hebei Province was a carbon sink.Spatially,the density of carbon sink declined from southeast to northwest.The carbon sequestrated by wheat and corn plants accounted for the largest proportion.In addition,the process of agricultural irrigation was the main controlling factor for carbon sequestration.The carbon emitted from fertilizers contributed the biggest proportion among the three major carbon emission sources of the farmland ecosystems.
Based on the statistic data of crop yield,planting area,effective irrigation area,fertilizer usage and agricultural machinery power of Hebei Province from 1989 to 2008,the carbon source and sink of the farmland ecosystems in Hebei Province were estimated.Furthermore,the temporal and spatial variations and the influencing factors of carbon source and sink were analyzed.The results showed that the total carbon sequestration and emission of the farmland ecosystems in Hebei Province showed a gradually rising process in the last 20 years,and more carbon was sequestrated than emitted.Overall,the farmland ecosystem of Hebei Province was a carbon sink.Spatially,the density of carbon sink declined from southeast to northwest.The carbon sequestrated by wheat and corn plants accounted for the largest proportion.In addition,the process of agricultural irrigation was the main controlling factor for carbon sequestration.The carbon emitted from fertilizers contributed the biggest proportion among the three major carbon emission sources of the farmland ecosystems.
Abstract:
The study of Qinghai Tibet Plat eau has been a focus in geology and geography for researchers home and abroad for a long time.The range of Qinghai Tibet Plateau is different from administrative division.There are many differences among the ranges based on different criterions and purposes.Based on the characters of to pography,we used the data of A ster G DEM and the method of digital terrain analysis to extract the boundary of Qing hai Tibet Plateau semiautomatically with supporting of the ArcGIS,and its to pography was identified and divided automatically.16 kinds of geomorphic distribution maps were acquired.The results showed that the dominating topographies were high-elevation hills,low-relief high-hill, middle-relief subalpine and middle-relief high-hill,the areas accounted for 60.58% in Qinghai Tibet Plateau.The terrain was quite gently in inner plateau,had a little large relief in marginal area,indicating significant difference between plateau and the adjacent regions into pography.
The study of Qinghai Tibet Plat eau has been a focus in geology and geography for researchers home and abroad for a long time.The range of Qinghai Tibet Plateau is different from administrative division.There are many differences among the ranges based on different criterions and purposes.Based on the characters of to pography,we used the data of A ster G DEM and the method of digital terrain analysis to extract the boundary of Qing hai Tibet Plateau semiautomatically with supporting of the ArcGIS,and its to pography was identified and divided automatically.16 kinds of geomorphic distribution maps were acquired.The results showed that the dominating topographies were high-elevation hills,low-relief high-hill, middle-relief subalpine and middle-relief high-hill,the areas accounted for 60.58% in Qinghai Tibet Plateau.The terrain was quite gently in inner plateau,had a little large relief in marginal area,indicating significant difference between plateau and the adjacent regions into pography.
2002(3):58-58, DOI: 10.13961/j.cnki.stbctb.2002.03.017
Abstract:
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
2001(1):30-34, DOI: 10.13961/j.cnki.stbctb.2001.01.008
Abstract:
水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.
水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.
Abstract:
In August,2008,the wetlands in the Yellow River Delta,covered with different plant communities,were selected as the study objects to investigate the spatial distribution characteristics and the reserves of phosphor(P) and sulfur(S) in wetland soils. Results showed that different plant communities could affect the contents of P and S differently. Total phosphorus(TP) content had no significant variation with the succession,while total sulfur(TS) content,varying in the "S" mode,was affected obviously by the period of plant community succession. As for the characteristics of vertical distribution,TP content was not remarkable,showing that TP in soils depends on parent material. However,the vertical distribution of TS was significant(CV10%) and its distribution was based on soil organic matter. Besides,the reserves and distributions of the two elements were also affected by plant communities differently. Both the reserve and the distribution of phosphorus varied little,fluctuating around 0.32 kg/m2 (0—60 cm). The reserve of S varied significantly from 0.17 kg/m2(the last stage of succession,0—60 cm)to 0.33 kg/m2 (bare beach,0—60 cm),fluctuating in "S" mode with the succession,while the distribution of S was not clear. Result from the research shows that the distributions of P and S in wetland soils are affected by plants and thus,right plants can be selected to apply in ecological rehabilitation of wetland. The research may provide a theoretical basis for the ecological rehabilitation of wetlands.
In August,2008,the wetlands in the Yellow River Delta,covered with different plant communities,were selected as the study objects to investigate the spatial distribution characteristics and the reserves of phosphor(P) and sulfur(S) in wetland soils. Results showed that different plant communities could affect the contents of P and S differently. Total phosphorus(TP) content had no significant variation with the succession,while total sulfur(TS) content,varying in the "S" mode,was affected obviously by the period of plant community succession. As for the characteristics of vertical distribution,TP content was not remarkable,showing that TP in soils depends on parent material. However,the vertical distribution of TS was significant(CV10%) and its distribution was based on soil organic matter. Besides,the reserves and distributions of the two elements were also affected by plant communities differently. Both the reserve and the distribution of phosphorus varied little,fluctuating around 0.32 kg/m2 (0—60 cm). The reserve of S varied significantly from 0.17 kg/m2(the last stage of succession,0—60 cm)to 0.33 kg/m2 (bare beach,0—60 cm),fluctuating in "S" mode with the succession,while the distribution of S was not clear. Result from the research shows that the distributions of P and S in wetland soils are affected by plants and thus,right plants can be selected to apply in ecological rehabilitation of wetland. The research may provide a theoretical basis for the ecological rehabilitation of wetlands.
Abstract:
Working out a small watershed planning on the Loess Plateau needs many kinds of geographical data. By taking the Majiagou watershed in Ansai County,Shannxi Province as a typical experimental area,taking the DEM of the watershed as the basic data set,and using ArcGIS and various space analysis technologies,data mining experiments on slope graduation,landform classification,and aspect graduation are conducted and a series of data mining parameters and the indexes for drawing up the planning are obtained. Based on the multi-dimensional geography spatial data sets,a new method of data superimposition and fusion that takes the value code as the core are proposed. The research result has a certain reference value in the planning instruction for other small watersheds on the Loess Plateau.
Working out a small watershed planning on the Loess Plateau needs many kinds of geographical data. By taking the Majiagou watershed in Ansai County,Shannxi Province as a typical experimental area,taking the DEM of the watershed as the basic data set,and using ArcGIS and various space analysis technologies,data mining experiments on slope graduation,landform classification,and aspect graduation are conducted and a series of data mining parameters and the indexes for drawing up the planning are obtained. Based on the multi-dimensional geography spatial data sets,a new method of data superimposition and fusion that takes the value code as the core are proposed. The research result has a certain reference value in the planning instruction for other small watersheds on the Loess Plateau.
Variations of Soil Moisture and Nutrients in Alfalfa Field in Southern Ningxia Hui Autonomous Region
Abstract:
In the semi-arid hilly region of South Ningxia Hui Autonomous Region,three-year,seven-year,eleven-year,and nineteen-year old alfalfa fields and seven-year old alfalfa fields at uphill,middle slope,and downhill were taken as study objects.The dynamics of the dried soil layer(0—5 m) and soil moisture and nutrients were analyzed.The results show that both slope position and plant age affected soil moisture contents.The average moisture content of 0—5 m soil profile on the uphill alfalfa field was 6.34%,which was substantially lower than that on middle slope and downhill fields.The average moisture contents in 0—5 m soil profile decreased on the alfalfa fields as in order of three-year,seven-year,nineteen-year,and eleven-year,and soil drying index(SDI) decreased as in order of uphill,middle slope,downhill and three-year,seven-year,nineteen-year,and eleven-year.The dying degree declined as soil depth increased.After the alfalfa aged,soil moisture content could recover but took a long time.On all the alfalfa fields in this study,the average content of soil organic matter,total N,available N,total P,available P,and available K all increased in the fields from uphill to downhill.As the soil depth increased,the soil organic matter,total N,available N,total P,and available P decreased.As the age of alfalfa increased,the soil organic matter,total N,total P,available P,and available K exhibited a declining trend,but the available N increased first and then decreased with the age of alfalfa in the field.When alfalfa field was very old,the soil organic matter and total N began to accumulate but was still at a relatively low level.
In the semi-arid hilly region of South Ningxia Hui Autonomous Region,three-year,seven-year,eleven-year,and nineteen-year old alfalfa fields and seven-year old alfalfa fields at uphill,middle slope,and downhill were taken as study objects.The dynamics of the dried soil layer(0—5 m) and soil moisture and nutrients were analyzed.The results show that both slope position and plant age affected soil moisture contents.The average moisture content of 0—5 m soil profile on the uphill alfalfa field was 6.34%,which was substantially lower than that on middle slope and downhill fields.The average moisture contents in 0—5 m soil profile decreased on the alfalfa fields as in order of three-year,seven-year,nineteen-year,and eleven-year,and soil drying index(SDI) decreased as in order of uphill,middle slope,downhill and three-year,seven-year,nineteen-year,and eleven-year.The dying degree declined as soil depth increased.After the alfalfa aged,soil moisture content could recover but took a long time.On all the alfalfa fields in this study,the average content of soil organic matter,total N,available N,total P,available P,and available K all increased in the fields from uphill to downhill.As the soil depth increased,the soil organic matter,total N,available N,total P,and available P decreased.As the age of alfalfa increased,the soil organic matter,total N,total P,available P,and available K exhibited a declining trend,but the available N increased first and then decreased with the age of alfalfa in the field.When alfalfa field was very old,the soil organic matter and total N began to accumulate but was still at a relatively low level.
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Journal Information
- Founded in 1981, bimonthly
- CN：
61-1094/X
- ISSN：
1000-288X
- Administrted by：
Chinese Academy of Sciences
- Sponsored by：
Institute of Soil and Water Conservation, CAS & MWR;
Monitoring Center of Soil and Water Conservation, Ministry of Water Resources - Published by：
Science Press
- Editor-in-Chief：
CHEN Diyi
- Deputy Editor-in-chief：
ZHAO Yongjun
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