Abstract:［Objective］ The purification effect of ecological buffer zones （EBZs） on nitrogen and phosphorus pollutants in surface runoff and seepage water under the combined of different internal and external factors was explored to provide an optimized design basis for the control of agricultural non-point source pollution. ［Methods］ The purification capacity of EBZs for nitrogen （TN） and phosphorus （TP） pollutants in both runoff and seepage water was evaluated using an orthogonal experimental design， while two internal factors （vegetation configuration and slope gradient） and two external factors （influent pollutant concentration and flow rate） were investigated， and range analysis was applied to quantify their relative contributions to pollutant removal efficiency. ［Results］ The removal efficiencies of EBZs for TN and TP in seepage water （21.31% and 29.80%， respectively） were significantly higher than those in surface runoff （16.91% and 23.04%， respectively）. Composite vegetation configurations showed better pollutant interception effects than pure herbaceous configurations， with the shrub + herb combination achieving the best results. The average removal rates of TN and TP in surface runoff were 20.16% and 27.24%， respectively， and in seepage water were 24.54% and 33.89%， respectively. Meanwhile， the influence degrees of different internal and external factors on various pollutants varied significantly in EBZs， but generally followed the order： vegetation configuration （most dominant） > influent concentration > slope gradient > flow rate （least influential）. ［Conclusion］ The vegetation configuration has the greatest impact on the pollutant interception capacity of EBZs. However， as the slope， inflow rate， and influent pollutant concentration increase， the pollutant removal rates of EBZs with different vegetation configurations generally show a downward trend.

Abstract:［Objective］ The effects of gravel content and rainfall intensity on runoff and sediment production characteristics of engineering accumulation bodies composed of loam and aeolian sandy soil were investigated， in order to provide theoretical guidance and data support for effective soil erosion prevention in production and construction projects. ［Methods］ Indoor rainfall simulation experiments were conducted using soil-rock mixed accumulation bodies as representative engineering erosion underlay surfaces， while the runoff and sediment production characteristics were quantitatively analyzed under four gravel content levels （0， 10%， 20%， and 30%） and three rainfall intensities （1.0， 1.5， and 2.0 mm/min）. ［Results］ ① Both accumulation bodies exhibited a ‘first increasing， then fluctuating’ trend in runoff rate. Among them， aeolian sandy soil accumulation bodies demonstrated lower runoff rates and hydraulic power than those of loam under low rainfall intensities （1.0 and 1.5 mm/min）. However， they showed greater growth rates under high rainfall intensity （2.0 mm/min） and high gravel content （30%）， the aeolian sandy soil exhibited greater growth rates， reaching or even exceeding loam levels， indicating potential for more severe erosion under similar conditions. ② Erosion rates of both accumulation bodies increased with an increase in rainfall intensity and decreased with an increase in gravel content， with aeolian sandy soil consistently exhibiting higher erosion rates. And for aeolian sandy soil， maximum reductions in erosion rate occurred at 10% gravel content under 1.0 mm/min （11.89%） and 1.5 mm/min （73.10%） rainfall， and at 30% gravel content under 2.0 mm/min （26.16%） rainfall. For loam， maximum reductions occurred at 30% gravel content under 1.5 mm/min （75.23%） and 2.0 mm/min （56.35%） rainfall. ③ Aeolian sandy soil demonstrated 16.09%—26.92% reductions in hydraulic power at 10% gravel content relative to that in the pure soil. Loam exhibited 18.71%—23.13% reductions in hydraulic power at 30% gravel content under 1.5—2.0 mm/min rainfall， whereas gravel showed limited mitigation effects under 1.0 mm/min rainfall. ［Conclusion］ Aeolian sandy soil accumulation bodies demonstrated accelerated runoff rates and hydraulic power growth under high rainfall intensity （2.0 mm/min） and high gravel content （30%）， potentially leading to severe erosion which reaching or exceeding loam levels. For both soil types， erosion rates were positively correlated with rainfall intensity and negatively correlated with gravel content.

Abstract:［Objective］ Using the chemical element records of surface sediments in Horqin sandy land as an entry point， this study aims to reveal the degree and spatial characteristics of chemical weathering， analyze the main factors influencing the chemical weathering of surface materials， and provide a scientific basis for further understanding the migration processes of surface materials in Horqin sandy land， as well as for its ecological protection and restoration efforts. ［Methods］ 118 surface sediment samples from Horqin sandy land， and were collected and analyzed multiple chemical weathering indices， including chemical alteration index（CIA）， plagioclase weathering index（WIP）， plagioclase index of alteration（PIA）， Compositional varibability index （ICV）， and geochemical triangular diagrams were utilized to assess the spatial weathering characteristics of the surface sediments in Horqin sandy land. Meanwhile factors influencing regional weathering were also investigated. ［Results］ ① Horqin sandy land as a whole was in the initial stage of chemical weathering， with insignificant differences in weathering degree among different types of sandy land. The chemical weathering intensity in the southwestern and central regions was slightly higher than in other areas. while the surface sediments exhibited low maturity and were primarily composed of first-cycle sediments. Weathering was dominated by plagioclase weathering， in the stage of Na and Ca leaching. ② Provenance discriminant diagrams and binary functional diagrams indicated that the geochemical characteristics resembled those of intermediate-acid granites. This confirmed that the parental rocks of the sediments were mainly derived from intermediate-acid granites. The rock types and mineral composition of the source area determined the initial conditions for weathering， thereby influencing the weathering process. ③ Climatic conditions were a significant factor controlling weathering. Chemical weathering intensity in the western part of the sandy land correlated with temperature， while in the eastern part， it correlated with precipitation. Additionally， sedimentary differentiation also caused variations in CIA values， consequently affecting chemical weathering intensity. ［Conclusion］ Chemical weathering in Horqin sandy land exhibits an ‘overall weak but locally heterogeneous’ pattern： Provenance attributes （intermediate-acid granites） establish the weathering foundation， climate drives spatial differences， and sedimentary differentiation processes further exacerbate the variations in weathering intensity.

Abstract:［Objective］ The influence of applying Baijiu wastewater sludge to pepper cultivation on soil fertility， crop yield， and heavy metal content is analyzed， providing a theoretical reference for the efficient resource utilization of Baijiu wastewater sludge. ［Methods］ Based on the characteristics of Baijiu wastewater sludge being rich in nitrogen， phosphorus， and potassium with low heavy metal content， its properties were optimized through granulation. Pepper was selected as the test plant. Granulated Baijiu wastewater sludge was applied to potted pepper soil at rates of 1 500—6 000 kg/hm² based on the local nutrient requirements calculated from pepper yield. Controls included soil with no Baijiu sludge application （CK） and soil with conventional compound fertilizer （F）. ［Results］ ① The treatment of 6 000 kg/hm² （W₄） demonstrated the best comprehensive effect. Compared to CK， it increased soil pH and electrical conductivity （EC） by 7.37% and 59.21%， respectively. Soil organic matter （OM）， available phosphorus （AP）， available potassium （AK）， alkaline nitrogen （AN）， ammonium nitrogen （NH₄⁺-N）， and nitrate nitrogen （NO₃⁻-N） increased by 72.73%， 93.28%， 62.24%， 24.08%， 63.40%， and 14.91%， respectively. ② The heavy metal contents in soil under different treatments were far below the standard limits and met class Ⅰ standards. Furthermore， the contents of iron （Fe） and aluminum （Al） in the treated soil were relatively low， making soil acidification and compaction unlikely. ③ Application of granular Baijiu sludge significantly promoted pepper growth. Specifically， the W₄ treatment increased plant height and chlorophyll content by 68.84% and 65.48%， respectively， compared to CK， and the pepper yield was the highest， reaching 33 180 kg/hm². ［Conclusion］ Application of granular Baijiu sludge can significantly improve soil physicochemical properties， markedly enhance soil fertility， and effectively promote pepper growth.

Abstract:［Objective］ The effects of single amendment application and combined application of organic fertilizer with amendments on the distribution characteristics of soil aggregates and rice yield of acidic paddy soil were analyzed， in order to provide a scientific basis for the amelioration of acidic paddy soil and the improvement of rice yield. ［Methods］ Acidic paddy soil was selected as the research object. Seven treatments were set up： control （CK）； calcium magnesium phosphate fertilizer （T₁）， calcium carbonate powder （T₂）， calcium magnesium silicate conditioner （T₃）， organic fertilizer+calcium magnesium phosphate fertilizer （T₄）， organic fertilizer+calcium carbonate powder （T₅）， and organic fertilizer+calcium magnesium silicate conditioner （T₆）. The soil aggregate distribution characteristics， aggregate stability， and rice yield under different treatments were compared. ［Results］ ① Overall， the soil pH value and soil nutrient indicators of T₁—T₆ showed an increasing trend compared with CK， but not reaching statistical significance. Among them， T₅ showed the highest pH value at 4.8， an increase of 0.4 units over CK. Additionally， T₁ recorded the highest available phosphorus content at 9.74 mg/kg， representing a 152% increase compared to CK. ② The content of >5 mm aggregates in air-dried soil aggregates of T₁—T₆ was significantly higher than in CK， with T₅ treatment showing the most pronounced effect， an increase of 6.37% compared to CK. ③ The mean weight diameter （MWD）， geometric mean diameter （GMD）， and >0.25 mm aggregate content （R_0.25） of air-dried and water-stable aggregates in T₄—T₆ were significantly higher than in CK， increasing by 7.51%—8.61%， 26.0%—28.6%， and 6.29%—6.50%， respectively. And the fractal dimension D significantly decreased. ④Rice yield under T₁—T₆ treatments was significantly higher than that of CK， with the T₅ treatment showing the highest increase of 17.46%. ［Conclusion］ The combined application of organic fertilizer with calcium magnesium phosphate fertilizer， calcium carbonate powder， and calcium magnesium silicate conditioner significantly improves soil structural stability and rice yield， with the organic fertilizer+calcium carbonate powder treatment （T₅） demonstrating the optimal effect.

Abstract:［Objective］ The impact of different human disturbances on the health of a soil-grassland system was evaluated quantitatively to provide a scientific basis for grassland ecological restoration， formulation of management measures， and sustainable utilization. ［Methods］ Using the grassland of Xilamuren in Inner Mongolia as the research object， we compared and analyzed the physicochemical properties and vegetation characteristics of the grassland soil under the four types of disturbance methods， namely enclosure， grazing， reclamation and tourism， and used grey correlation analysis and the fuzzy comprehensive evaluation method to assess the system health status. ［Results］ ① The percentage contents of gravel and sand were highest in the tourist area （14.98% and 67.79%， respectively） and lowest in the enclosure area （9.02% and 55.38%， respectively）. The highest percentages of clay （15.45%） and silt （20.13%） were found in the enclosure zones， whereas the lowest values （7.21% and 10.02 %， respectively） were found in the tourism zones. The highest soil bulk density （1.61 g/cm³） was also found in tourism zones. No significant differences were detected in the soil moisture and saturated water-holding capacity within the soil layers of the sampling sites. ② The highest soil organic matter （12.98 g/kg） and total nitrogen （0.73 g/kg） were observed in enclosure zones， whereas the lowest （8.23 g/kg and 0.46 g/kg） values were found in tourism zones. The total phosphorus and potassium levels among the different human disturbances were ranked as follows： reclamation > enclosure > grazing > tourism. Furthermore， 9.08 mg/kg more available phosphorus in reclaimed areas was higher than in tourism zones， whereas the content of available potassium （268 mg/kg） in the enclosure zones was significantly higher than that in other sites. ③ Total plant biomass of sampling site was ranked as enclosure （342.67 g/m²） > reclamation （155.29 g/m² > grazing （112.93 g/m²） > tourism （43.51 g/m²）. ④ Soil quality and grassland health were ranked as follows： enclosure > reclamation > grazing > tourism. ［Conclusion］ Significant differences in the soil physicochemical properties and plant biomass were observed under different human disturbance. Enclosure zones demonstrated the best soil quality and grassland health， whereas tourism zones showed the worst conditions. Both reclamation and grazing negatively affected soil quality and grassland health.

Abstract:［Objective］ The response of the shear resistance characteristics of Hippophae rhamnoides root-soil complexes to stubble rejuvenation was examined in the Pisha sandstone area of Inner Mongolia. The aim was to obtain data for providing theoretical guidance for optimizing the biomechanical strategies used for conserving soil and water and sustainably managing H. rhamnoides plantations in this region. ［Methods］ The 8-year-old declining H. rhamnoides plantations in the Pisha sandstone area of Inner Mongolia were selected as research objects. The root distribution and shear characteristics of root-soil complexes were compared between a stubble rejuvenation group （after one growing season） and a control group. ［Results］ The number， length， surface area and dry weight of the roots with a 0—1.5 mm diameter in the root system of H. rhamnoides were 9.29%， 0.03%， 8.35%， and 8.60% larger， respectively， in the rejuvenation group than in the control group， indicating that stubble rejuvenation promoted the growth of fine roots. The shear and residual shear strengths of the root-soil complexes， the cohesion and residual cohesion， and the internal and residual internal friction angles were 4.08% and 28.80%， 8.25% and 50.64%， and 18.00% and 25.57% larger， respectively， in the stubble group than in the control group in the soil layer where the roots were concentrated. The shear and residual shear resistances of the root-soil complexes in the stubble and control H. rhamnoides were higher than those of plain soil； that is， the shear resistance of root-containing soil was higher than that of root-free soil. ［Conclusion］ Stubble rejuvenation promoted the growth of fine roots. The activities of fine roots increased the number of interactions between roots and soil， and the root-soil bonding strengthened. The shear strength of the Hippophae rhamnoides root-soil complex after stubble rejuvenation increased through the cementation of the fine root network and the entanglement of fine roots， which increased the stability and erosion resistance of the soil.

Abstract:［Objective］ The soil nutrients and stoichiometric characteristics of different artificial forest types in Zizhou County， Shaanxi Province were analyzed， in order to provide a scientific basis for ecological management and restoration in the region. ［Methods］ Five representative artificial forest types in Zizhou County （Pinus tabuliformis pure forest， Platycladus orientalis pure forest， Robinia pseudoacacia pure forest， Prunus armeniaca×P. orientalis mixed forest， and R. pseudoacacia×P. armeniaca mixed forest） were selected as the study objects， with natural grassland as the control. The contents of soil organic carbon （SOC）， total nitrogen （TN）， and total phosphorus （TP） as well as their ecological stoichiometric characteristics of different soil layers （0—100 cm） under different forest stand types were investigated. ［Results］ The ranges of soil C， N， and P contents under five artificial forest types were 4.56—3.31 g/kg， 0.29—0.23 g/kg， and 0.58—0.55 g/kg， respectively. Within the 0—100 cm soil profile， the P. armeniaca×P. orientalis mixed forest showed the highest C， N， and P contents， with significant differences compared to other forest stand types. Both soil C and N contents exhibited decreasing trends with increasing soil depth. The TN content in mixed forests was higher than that in the pure forests of all soil layers. The SOC and TP contents in all soil layers except the 60—80 cm and 80—100 cm layers were highest in the P. armeniaca×P. orientalis mixed forest. The variation ranges of C∶P， C∶N， and N∶P in soil of the five artificial forest types were 7.75—5.69， 16.30—14.14， and 0.50—0.40， respectively. For all soil layers， C∶P ratios were the lowest in the pure forest of P. orientalis， while N∶P ratios were higher in mixed forests than in pure forests. TN and SOC were significantly positively correlated with N∶P in different forest stand types， and they were significantly positively correlated with both C∶P and N∶P at different soil depths. ［Conclusion］ Soil nutrients and stoichiometric characteristics differ significantly of different artificial forest types. Overall， the P. armeniaca×P. orientalis mixed forest demonstrates superior soil nutrient level and stoichiometric characteristics compared to other forest stand types. These findings indicate that mixed forests can enhance forest stand productivity and stability.

Abstract:［Objective］ The precision of using coupled prediction models in quantifying microtopographic soil loss was evaluated for varying slopes， rainfall intensities， temporal scales， and surface treatments in order to provide scientific referrences for microtopographic soil loss prediction. ［Methods］ The microtopography of bare loess slopes was studied. The soil conservation service curve number （SCS-CN） model was modified according to measured surface runoff （Q_T） and surface roughness （SR） values for predicting runoff volume. The modified model was then coupled to the revised universal soil loss equation （MUSLE） for predicting soil erosion. ［Results］ ① The modified models， SCS-Q （using CN values back-calculated from Q_T） and SCS-SR （modified via SR）， predicted runoff （Q_CN and Q_SR， respectively） with R² values of 0.933 8 and 0.769 1， respectively. The developed models were more accurate by 32% and 9%， respectively， than the original SCS-CN model， which predicted runoff， Q_O， with an R² of 0.705 6. ② The coupled models produced more accurate microtopographic erosion predictions than the RUSLE models. The MUSLE-SR model （combining SCS-SR with MUSLE） was more accurate （NSE ∈ ［0.50， 0.94］） than the MUSLE-Q model （combining SCS-Q with MUSLE） （NSE ∈ ［0.23， 0.94］）. ③ During the microtopographic soil loss prediction， the surface measures more strongly affected the microtopographic erosion prediction accuracy of the coupled model （ΔNSE=63%） than the rainfall intensity （ΔNSE=52%） or slope （ΔNSE=40%）. ［Conclusion］ The microtopographic soil erosion prediction accuracy of the coupled models considerably increased with rainfall duration： accuracy was low in the first 20 min of rainfall （R²<0.5） but markedly increased after 20 min （R²>0.8）.

Abstract:［Objective］ The variation pattern of soil nutrients along the altitude gradient and the correlation between various factors in Dayao Mounatins of Guangxi Zhuang Autonomous Region were analyzed in order to provide scientific guidance for study of the distribution pattern of subtropical montane forest communities and forest hydrological mechanisms. ［Methods］ The nutrients of the surface soils （0—10 cm and 10—20 cm） at different altitude gradients in Dayao Mountain were analyzed using One-way ANOVA and multiple comparisons. ［Results］ ① The physical and chemical properties of forest soils in Dayao Mountain showed significant spatial heterogeneity along the altitude gradient. The maximum water holding capacity， soil organic matter， total nitrogen， and hydrolyzed nitrogen content of the soil showed a fluctuating increasing trend with altitude， with their coefficients of variation all exceeding 40%， indicating pronounced spatial heterogeneity. The soil bulk density and pH value showed a fluctuating decreasing trend along the altitude gradient， while the total phosphorus and total potassium contents showed no significant difference along the altitude gradient. ② In the vertical profile， the soil organic matter， total nitrogen， and hydrolyzed nitrogen contents in the 0—10 cm soil layer were 65.21%， 57.07%， and 55.24% higher than those in the 10—20 cm soil layer， respectively， showing a typical “surface accumulation” pattern. ③ Correlation analysis showed highly significant correlations （p<0.01） between soil organic matter and indicators such as soil bulk density， total nitrogen， and hydrolyzed nitrogen， suggesting that soil organic matter can effectively improve soil structure and promoting material cycling by reducing soil compactness， enhancing colloid adsorption， and stimulating microbial mineralization， thereby improving aggregate stability and nutrient availability. ［Conclusion］ The physical and chemical properties of forest soils in Dayao Mountain show significant spatial heterogeneity along the altitude gradient. Organic matter， total nitrogen， and hydrolyzed nitrogen contents increase significantly along the altitude gradient （the coefficient of variation >40%）， and are more than 50% higher in the 0—10 cm soil layer than in the 10—20 cm soil layer， showing a typical “surface accumulation” pattern. Organic matter is significantly correlated with bulk density， nitrogen， and other soil indicators， indicating that it can effectively promote soil nutrient cycling by improving soil structure.

Abstract:［Objective］ This study investigated the litter decomposition dynamics and their influencing factors of the dominant species， Larix gmelinii， and its associated species， Betula platyphylla， in the permafrost region of the Great Xing’an mountains， in order to provide scientific insights for maintaining forest ecosystem stability， enhancing carbon sequestration capacity， and formulating adaptive management strategies under permafrost degradation. ［Methods］ A litterbag experiment was conducted using three treatments of L. gmelinii litter （needleleaf）， B. platyphylla litter （broadleaf）， and a combined litter （3∶1 ratio）. Over a two-year in-situ decomposition period， litter mass loss dynamics and their relationships with C and N content were systematically analyzed. The Olson exponential model was used to calculate the times required for 50% and 95% litter decomposition. ［Results］ ① The litter mass loss over the two-year decomposition period was fastest for broadleaf litter （23.53%）， followed by the mixed litter （16.41%）， and slowest in the needleleaf litter （14.47%）， with 65.11%—66.80% of the total mass loss occurring during the first year. The measured mass-loss rates of the mixed litter were significantly higher than predicted in the first year of decomposition， indicating a synergistic effect. ② Broadleaf and mixed litter mass loss showed highly significant positive correlations with N content and negative correlations with the C/N ratio. However， there were no significant correlations between needleleaf mass loss and N content or C/N ratio. ③ The Olson model effectively described the decomposition dynamics （R²>0.89）. The time required for 50% and 95% litter decomposition was shortest for broadleaf litter （5.45 years and 23.55 years）， followed by mixed litter （9.32 years and 40.27 years）， and slowest for needleleaf litter （11.55 years and 49.93 years）. ［Conclusion］ The rapid decomposition of broadleaf litter may be attributed to its high N content and low C/N ratio. The complete decomposition of needleleaf and mixed litter requires over four decades， nearly double the time for complete broadleaf litter decomposition， which requires slightly over two decades. The mixed litter mass loss only exhibited synergistic effects during the first yesr of decomposition. These slow decomposition processes are critical for maintaining the C-N balance in the permafrost-vegetation feedback system and for enhancing the ecological barrier functions of cold region ecosystems.

Abstract:［Objective］ The stress tolerance of Amygdalus pedunculata seeds during germination were investigated， and the differences in seed traits and germination characteristics among different provenances were analyzed， in order to provide theoretical guidance for selecting superior A. pedunculata provenances and their rational introduction and ecological restoration in arid and saline-alkali areas. ［Methods］ Seeds from four provenances of A. pedunculata were used as experimental materials： Xiaojihan Township（XJH）， Yuyang District， Yulin City； Jinjie Town（JJZ）， Shenmu City， Yulin City； Jinshan Town（JSZ）， Guyang County， Baotou City； and Saihantala Town（SHT）， Sonid Right Banner， Xilin Gol League. Polyethylene glycol （PEG-6000） and NaCl were used to simulate drought stress and salt stress， respectively. Changes during the germination period were investigated. Principal component analysis （PCA） and the membership function method were employed for a comprehensive evaluation of seed stress tolerance. ［Results］ There were significant differences in drought tolerance and salt tolerance among the four A. pedunculata provenances， respectively ranked as SHT>XJH>JJZ>JSZ and XJH>JJZ>SHT>JSZ. The comprehensive evaluation index of drought tolerance was 90.12 for SHT provenance， while the index for salt tolerance was 89.51 for XJH provenance. ［Conclusion］ The SHT provenance is more drought-resistant and the JJZ provenance is more salt-resistant， revealing that seed stress tolerance varies among different A. pedunculata provenances.

Abstract:［Objective］ The soil erosion and quality under chestnut forests were quantitatively analyzed at earth-rocky mountainous area in northern China to provide a theoretical basis for studying， managing， and conserving the soil and water in economic forests in mountainous area with rocky soil in northern China. ［Methods］ Twelve soil parameters， such as soil erosion modulus， soil particle size distribution， organic matter， and total nitrogen， were measured for chestnut forests and the surrounding shrub forests in the Zhujiawan （Miyun District） and Badaohe （Huairou District） watersheds in Beijing City from 2022 to 2024. The soil fertility， soil coarsening degree， and erosion intensity were analyzed， and the soil quality index （SQI） was evaluated using principal component analysis. ［Results］ ① The annual average soil erosion modulus of the chestnut forest was 8.3 times higher than that of the shrub forest. The rill erosion modulus of the chestnut forest after flood season was more than 13 000 t /km²， and the understory erosion was intense from 2023 to 2024. ② The coarse sand （0.5—2 mm） content in the 1 cm soil of the surface was approximately 1.3 times higher on average in the chestnut forest than in the shrub forest， indicating the soil was coarser in the chestnut forest. ③ The average organic matter， total nitrogen， and alkali-hydrolyzed nitrogen contents in the soil of chestnut forest were less than one-quarter of those in the adjacent shrubland. The available potassium content in the chestnut forest soil was approximately half of that in the adjacent shrubland. The available phosphorus and low-availability potassium contents showed enrichment phenomenon in the chestnut forest soil. ④ The SQI of the chestnut forest was significantly lower than that of shrubland （p=0.025<0.05）. ［Conclusion］ The soil in chestnut forests at earth-rocky mountainous area in northern China was experiencing severe erosion， soil coarsening， and nutrient loss； the quality of this soil was lower than that of the soil in the surrounding shrub forests. Scientific land management measures need to be implemented to increase the quality of this soil.

Abstract:［Objective］ The impacts of the land use patterns on the water infiltration in red soil regions were studied to provide a scientific basis for soil and water conservation as well as land use planning. ［Methods］ A double-ring infiltrometer was used to quantify the water infiltration characteristics in red soils under six land use patterns： forest land， shrubland， grassland， peanut cropland， maize cropland， and bare land. Four infiltration models （Philip， Kostiakov， Horton， and Mezencev） were used to simulate infiltration process. The differences in the water infiltration characteristics were compared among the land use types， and the influence of the physical properties of the soil on the water infiltration capacity was systematically investigated. ［Results］ ① The initial， average， and steady infiltration rates of the red soil ranged from 3.50 to 41.93， 2.03 to 28.37， and 1.28 to 17.15 mm/min， respectively. The water infiltration capacity decreased as follows： forest land > bare land > shrubland > maize cropland > grassland > peanut cropland； ② The Kostiakov model most accurately simulated the red soil infiltration processes among the four models， with an R² ranging from 0.91 to 0.99 for all land use pattern. In contrast， the Horton and Mezencev models were particularly accurate in modeling the water infiltration of grandland and peanut cropland， with R² values of 0.93 and 0.91， respectively. The accuracy of the Philip model in modeling the water infiltration was relatively low. ③ The key physical factors influencing the water infiltration were the noncapillary porosity， natural moisture content， and clay content， which contributed 25.80% to 32.30%， 19.20% to 21.20%， and 16.30% to 20.70% of the total water infiltration capacity. ［Conclusion］ The water infiltration capacity of red soils varies widely across different land use pattern， with that under forest land being the highest. Certain agroforestry practices should be implemented to increase the water infiltration capacity of agricultural red soils to conserve soil and water.

Abstract:［Objective］ The carbon storage and density patterns at the Heilongshan forest farm ecosystem were quantify analyzed， and effective carbon sequestration enhancement strategies were put forward， to provide critical data for assessing regional forest carbon sink potential. ［Methods］ Based on field investigations and laboratory analysis， combined with biomass models of trees and forest resource data and using GIS technology， the distribution characteristics of carbon storage and carbon density of main forest types at Heilongshan forest farm were studied and pathways for increasing carbon sequestration were proposed. ［Results］ ① The total carbon storage and average carbon density of the forest ecosystem was 1.87×10⁶t and 173.57 t/hm²， respectively. The average carbon density was in the following order： soil layer > tree and shrub layer > humus layer > litter layer > understory shrub layer > understory herbaceous layer. The allocation characteristics of carbon storage were consistent with carbon density. Soil carbon storage was the highest， accounting for 66.30% of the total carbon storage. ② The total carbon storage and carbon density of the arbor forests were 5.44×10⁵ t and 56.72 t/hm²， respectively. Betula platyphylla and Ulmus pumila forests were the major sources of carbon storage in the arbor forests， accounting for 84.36% of the arbor forests carbon storage. They are mainly composed of middle-aged and young forests with great potential for carbon sequestration. ③ Altitude， slope， and aspect regulated the spatial distribution of factors， such as water and heat， soil， and human interference， which had a significant impact on the spatial allocation of forest ecosystem carbon storage and carbon density. ［Conclusion］ In the future， the forests of Heilongshan forest farm have great carbon sequestration capacity and potential. Strengthening forest nurturing， preventing fires， controlling forest pests and diseases， protecting forest soil and other measures to improve forest quality and reduce carbon emissions are effective ways to increase forest sinks in Heilongshan forest farm.

Abstract:［Objective］ The forest carbon sink value in the Inner Mongolia Autonomous Region was quantified， and pathways for realizing the value of ecological products were explored， in order to deeply understand the intrinsic mechanism of changes in the carbon sink value of forests in this area and provide theoretical references for promoting the sustainable management and value realization of forest ecological products. ［Methods］ The study focused on twelve prefecture-level cities （leagues） in the Inner Mongolia Autonomous Region， covering the period from 2009 to 2023. A multimetric framework was developed to quantify forest carbon sinks and analyze their spatiotemporal evolution， integrating carbon sequestration rate， optimal pricing， carbon tax， and afforestation cost methods for CO₂fixation. In addition， multiple regression models and grey relational analysis were employed to assess influencing factors and the degree of inter-factor association， thereby identifying potential pathways for realizing the value of forest carbon sink-based ecological products. ［Results］ ① The forest carbon sinks of all prefecture-level cities （leagues） in Inner Mongolia increased significantly， with the most notable growth observed in 2014. The total increase ranged from 160% to 200%， with Wuhai City， Bayan Nur City， and Ulanqab City exceeding 240%， and Ordos experiencing an increase of more than 50-fold. ② The forest carbon sink value in each prefecture-level city （league） showed an overall upward trend， with the fastest growth occurring in the central regions. Spatially， the pattern was characterized by higher values in the east and lower values in the west， with peak values in the northeast， declining from the northern and southern edges toward the center in the midland areas， and from northwest to southeast in the western regions. ③ Differences in geographical location， industrial structure， policy orientation， and forest age structure among the prefecture-level cities （leagues） resulted in significant spatial heterogeneity in the operational mechanisms and intensity of influencing factors. Specifically， Wuhai City， Bayan Nur City， Hinggan League， and Hulunbuir City exhibited stronger inter-factor correlations， while Alxa League， Hohhot City， and Chifeng City showed relatively weaker associations. The primary influencing factors included economic development， precipitation， forestry output value， forest coverage， and the scale of forest investment. ［Conclusion］ Forest carbon sink volume and value in Inner Mongolia displayed significant regional differentiation. Future policies should formulate carbon sink development strategies tailored to local conditions based on each prefecture-level city’s （league’s） resource endowments and ecological function positioning. Differentiated pathways for realizing forest carbon sink product value should be explored to promote efficient transformation and value realization through region-specific， refined management in Inner Mongolia.

Abstract:［Objective］ The study conducted a full life cycle carbon budget assessment and zoning of grain production in the Gansu section of the Yellow River basin to provide scientific support for regional grain security and ecological conservation. ［Methods］ This study focused on the Gansu section of the Yellow River basin. Based on multi-period data from 2000 to 2022， a carbon balance framework for the entire grain production cycle was constructed. The IPCC carbon conversion coefficient method， life cycle method， and empirical formula method were comprehensively used to measure the carbon budget level of grain production， reveal its spatiotemporal evolution patterns， and divide the carbon balance zones using a combination of dynamic and static methods. ［Results］ ① Carbon emissions from grain production in the study area showed a trend of ‘first increasing and then decreasing’， with 2015 as the turning point. The overall carbon sequestration exhibited a rising trend. ② In terms of temporal evolution， the dynamic balance level showed a trend of ‘first decreasing and then increasing’， and significantly improved after 2015. In terms of spatial pattern， the static balance level varied greatly across regions， with more than 90% of the regions achieving static balance by 2022. ③ The carbon balance zoning showed a distribution pattern of ‘high in the west and low in the east’. Since 2015， the dominant trend has been a favorable transition from imbalance to balance. ［Conclusion］ The overall carbon balance of grain production in the basin shows a positive trend of improvement， reflecting the gradual improvement of regional governance. To further improve the carbon balance of grain production， it is still necessary to develop differentiated green production strategies.

Abstract:［Objective］ This study aims to reveal the spatiotemporal distribution patterns and driving mechanisms of fluoride in the wetland water of the Xianghai National Nature Reserve， clarify the reasons for water quality exceeding the standards， provide theoretical support for the scientific formulation of ecological governance measures for the Xianghai wetland， and offer guidance for regional water environment governance and improvement of water quality in the basin. ［Methods］ Based on the long-term monitoring data of the national control section of the surface water in the Xianghai Nature Reserve from 2012 to 2021， different concentration characteristics of fluoride in the flood， normal water， and dry seasons were compared to clarify the interannual and seasonal variation characteristics of fluoride. Pearson’s correlation analysis was used to explore the correlations among various water quality indicators， and a Gibbs diagram was compiled to analyze the chemical characteristics of the surface water and interpret the natural sources of fluoride. ［Results］ ① From 2012 to 2021， the annual average fluoride concentration in the surface water of the Xianghai Reservoir ranged from 2.02 to 3.87 mg/L， chronically exceeding the class Ⅴ surface water quality standard （GB 3838—2002） by 0.36—1.61 times annually. ② Temporally， fluoride concentrations were higher in the dry season （3.54—3.66 mg/L） and lower in the wet season （2.76—2.87 mg/L）， exhibiting an initial decline， subsequent rebound， and final decline， with pronounced seasonal fluctuations. Spatially， concentrations at Yichangpao （1.56—3.20 mg/L， 2022） significantly exceeded those at Erchangpao （1.16—2.48 mg/L）. ③ The average content of total fluoride in the soil within the surrounding area of Xianghai Reservoir ranges from 1，013.91 to 2，067.12 mg/kg， and the water-soluble fluoride content reaches 10.45 to 50.12 mg/kg， which is much higher than the national background value. ④ The dominant hydrochemical types of surface water were HCO₃⁻-Na ∙ Mg and HCO₃⁻-Na， with fluoride enrichment being closely linked to regional evaporation concentration， dissolution-precipitation， and ion exchange processes. ［Conclusion］ Endogenous release is the primary pollution pathway for fluoride in the surface water of the Xianghai reservoir. Control measures should focus on endogenous pollution management and hydrological regulation.

Abstract:［Objective］ The rainfall characteristics in the Pisha sandstone area during the rainy season， soil moisture dynamics in different forest stands， and their responses to rainfall were analyzed， and the soil moisture variation patterns under different rainfall levels clarified， in order to provide a scientific basis for the selection of afforestation tree species in the Pisha sandstone area. ［Methods］ Based on fixed-point monitoring from July to September 2024， temporal and spatial soil moisture variations in soil depth from 0 to 100 cm in three plantations （pure Caragana korshinskii， pure Pinus tabuliformis， and mixed C. korshinskii × P. tabuliformis forests） in the Pisha sandstone area during the rainy season were analyzed. ［Results］ ① The soil moisture content of the mixed C. korshinskii × P. tabuliformis forest was the highest （26.15%）， followed by that of the pure P. tabuliformis forest （24.15%）， and the lowest in the pure C. korshinskii forest （16.43%）. The soil moisture content of the three forest stand types showed a fluctuating trend， first increasing， then decreasing， and then increasing again with increasing soil depth. ② With rainfall amounts from low to high， the soil moisture replenishment depths were 10 and 60 cm， respectively， and the soil moisture at a depth of 0—100 cm was replenished during heavy rainfall and rainstorm events. Under different rainfall amounts， the soil moisture increment of the pure C. korshinskii forest was the highest， followed by P. tabuliformis； the soil moisture increment of C. korshinskii × P. tabuliformis mixed forest was the lowest. ③ When rainstorm events occurred， all three stands showed responses in the 0—50 cm soil layer， the soil moisture content decreased slowly on the second day， and a water transportation lag appeared in the 50—100 cm soil layer. ［Conclusion］ The overall water holding capacity of mixed forests was better than those of the pure forests， however， the response to increased rainfall was weak. Although the water content of the pure C. korshinskii forest was low， the rainfall absorption capacity was stronger， and the deep soil rainfall response obviously lagged behind. For ecological restoration of the Pisha sandstone area， mixed C. korshinskii × P. tabuliformis forests should be preferentially selected to reduce water loss.

Abstract:［Objective］ To address the difficulties in quantifying the ecological losses caused by mining activities and the ecological benefits resulting from ecological restoration in mining areas， a scientific and credible assessment system for the ecosystem value of mining areas were constructed， in order to provide scientific references for enhancing the ecological value and ecological environment restoration and management in these areas. ［Methods］ To address the insufficient sensitivity of existing assessment methods for ecological service value to mining disturbances and ecological restoration effects， this study proposed an assessment system for the ecosystem value of mining areas based on the logical framework of ‘conceptual framework-indicator selection-system construction-application evaluation and verification’， focusing on four core functional values： ‘material production， energy flow， material cycling， and information transmission’. The assessment system was applied and validated at Buliangou mining area， Inner Mongolia. ［Results］ ① Among the four major functions of the mining area ecosystem， the energy flow function， driven by mining activities， contributed significantly to ecosystem value， reaching 688.317 9 million yuan/km² in 2022. ② The material cycling function， which included water conservation， windbreak， and sand fixation， was more significantly affected by compound disturbances， while the material production and information transmission functions were less affected. ③ Since the implementation of concentrated ecological restoration in 2019， the functional value of the mining area’s ecosystem had shown a positive improvement， with the ecological value in restored areas increasing by an average of 9.80×10⁴ yuan/km². The ecological value loss caused by mining disturbances exhibited a fluctuating decline. ④ The values of the four ecological functions demonstrated an overall “U-shaped” trend in response to variations in mining intensity. ［Conclusion］ The energy flow function significantly affects the total ecosystem value， while the material cycling function is a key influencing factor of the spatial heterogeneity of the ecosystem value in the mining area. The Buliangou mining area still requires enhanced ecological restoration to improve its ecosystem value.

Abstract:［Objective］ The pollution characteristics and ecological risks of polycyclic aromatic hydrocarbons （PAHs） in small coastal urban watersheds were explored， to provide a scientific basis for pollution source tracing and ecological risk management in such regions. ［Methods］ Houxi River watershed in Xiamen City was selected as the study area. Surface sediment samples （0—5 cm） were systematically collected from 18 sites and quantitatively analyzed for 16 PAHs using gas chromatography-mass spectrometry （GC-MS）. ［Results］ The results showed that the total content of 16 PAHs in the surface sediments of Houxi River watershed in Xiamen ranged from 115.02 to 807.27 ng/g， with an average of 371.33 ng/g. Among them， 4-ring and 5-ring PAHs had the largest proportions， both exceeding 25%. 2-ring PAHs had the smallest proportion， less than 4%. 3-ring and 6-ring PAHs were in the middle， around 20%. The spatial distribution showed a clear gradient among the upper， middle， and lower reaches： the upstream （A） had the lowest concentration （86.23—153.61 ng/g）， the middle reaches （B） were intermediate （298.23—456.71 ng/g）， and the downstream （C） had the highest concentration （435.24—656.11 ng/g）， indicating that the PAH pollution increased with the intensity of human activities. Based on the Sediment Quality Guidelines （SQGs）， the ecological risk assessment showed that most sampling sites fell between the lowest-level rare effect level （REL） and the second-lowest-level threshold effect level （TEL）， and a few sampling sites reached the medium-level occasional effect level （OEL）. None of the sampling sites reached the higher-level probable effect level （PEL） and the highest-level frequent effect level （FEL）. ［Conclusion］ The overall ecological risk of PAHs in the surface sediments of Houxi River watershed in Xiamen City is within a controllable range. However， variations in ecological risks across different sampling sites and PAH compounds should be given attention by relevant authorities.

Abstract:［Objective］ To map the distribution of landscape ecological risks in the Dabang River basin， we conducted in-depth analyses of the factors underlying landscape ecological risk in typical karst river basins and performed multi-scenario predictions to provide a scientific basis for enhancing local ecosystem stability and protecting the karst ecological environments. ［Methods］ An ecological risk assessment model was constructed integrating spatial autocorrelation analysis， optimal parameter geodetector， and multi-scenario simulation， we examined the ecological risk was examined in the Dabang River basin from 2013 to 2023. ［Results］ ① The largest land-use area transformation within the basin occurred between cultivated and forest land， with the most intense period of change from 2018 to 2023. ② Ecological risk in the basin had gradually improved. Medium-high-risk and high-risk areas were mainly located in the western part of Xixiu District， Liuzhi Special District， southwestern part of Guanling County， and the central part of Zhenning County， regions characterized by grassland， water areas， and construction land. Spatial agglomeration of ecological risk in the basin initially increased and then decreased. ③ Single-factor detection of landscape ecological risks in the basin indicated that Normalized Difference Vegetation Index （NDVI） （0.37）， night light （0.16）， and vegetation coverage （0.11） had the strongest explanatory power. Double-factor detection results were impacted by the interaction of NDVI∩soil type， distance to railway∩NDVI， and population distribution∩NDVI， suggesting that combined effects of natural and social factors are key to explaining changes in landscape ecological risk in the basin. ④ In multi-scenario predictions， overall landscape ecological risk was relatively high in the economic development （ED） scenario and relatively low in the ecological protection （EP） scenario. Considering both sustainable river basin development and ecological protection， the EP scenario offers a favorable path for future development of the river basin. ［Conclusion］ Landscape ecological risk in the Dabang River basin is mainly driven by interactions between natural and social factors. The ecological protection （EP） scenario results in a relatively low landscape ecological risk， making it an inevitable path for achieving sustainable development and building a beautiful China.

Abstract:［Objective］ The spatial heterogeneity patterns of land use in the New International Land-Sea Trade Corridor region were revealed， and the future land use patterns under different policy orientations were simulated， in order to provide a scientific basis for coordinating regional ecological conservation with economic development and optimizing the territorial spatial layout. ［Methods］ Land use intensity indices were calculated from 2002 to 2022. Spatial autocorrelation analysis， the optimal parameters-based geographical detector， and the geographically and temporally weighted regression model were employed to analyze spatial heterogeneity and its driving factors. Subsequently， the patch-generating land use simulation model was used to simulate land use patterns for 2032 under natural development， cropland protection， economic development， and sustainable development scenarios. ［Results］ ①From 2002 to 2022， the overall degree of regional land use remained stable at a medium level， with the proportion of relatively weak grade land increasing the most. Spatially， it presented the characteristics of ‘core expansion， ecological constraints， and axial agglomeration.’ ② Changes in land use intensity showed a significant positive spatial autocorrelation. High-high agglomeration areas expanded from single-core to multi-core linkages， whereas low-low agglomeration areas remained locked in ecologically sensitive zones. Driving factors demonstrated significant spatial heterogeneity： expressway density had a positive effect； slope， mean annual precipitation， and urban disposable income exerted negative effects； and mean annual temperature， population density， railway density， and road freight volume exhibited both of positive and negative effects. ③ Multi-scenario simulations showed that the Sustainable Development scenario yielded optimal outcomes： the increase in construction land slowed to 48.35%， forest area grew by 2.64%， and decline in cropland area moderated to 6.37%. ［Conclusion］ Land use changes in the New International Land-Sea Trade Corridor region result from the spatial interplay between natural constraints and strategic development imperatives. Future strategies should establish an ‘axial linkage and multi-core synergy’ development model， implement ‘eco-priority’ spatial governance， and strengthen corridor-hinterland coordination to transition from pursuing ‘corridor throughput’ to achieving ‘sustainable development gains.’

Abstract:［Objective］ Evaluation of the ecological sensitivity of water-level fluctuation zones of river-type reservoirs can clarify ecological risks， such as soil erosion and biodiversity decline in the region，in order to provide a basis for decision-making regarding the ecological safety of reservoirs. ［Methods］ The water level fluctuation zone of Longyangxia reservoir was taken as the research object， and GIS technique was used to evaluate four key factors： soil erosion sensitivity， biodiversity sensitivity， habitat sensitivity， and topographic sensitivity in the study area. The weight of each factor on comprehensive ecological sensitivity was determined， and comprehensive ecological sensitivity was calculated using the coefficient of variation method. ［Results］ ① The habitat and biodiversity sensitivities were moderately high， soil erosion sensitivity was moderately low， and topographic sensitivity was generally low. ② The topographic and habitat sensitivity factors had the highest weights in the comprehensive ecological sensitivity calculation at 38.4% and 25.5%， respectively. ③ A moderately low level of comprehensive ecological sensitivity was observed in 75.49% of the study area. ［Conclusion］ Topography sensitivity and habitat sensitivity were the dominant factors in the ecological sensitivity of the water level fluctuation zone of Longyangxia reservoir. The spatial distribution is characterized by the head of the reservoir showing higher sensitivity than the belly， and the belly showing higher sensitivity than the tail. Priority should be given to protecting the reservoir head.

Abstract:［Objective］ The spatio-temporal variation characteristics of temperature and precipitation in the Pearl River basin from 1993 to 2022 were analyzed， and to the future extreme climate changes were estimated and predicted，in order to provide a scientific basis for the prediction of climate change and disaster prevention and mitigation in the basin. ［Methods］ This study selected temperature and precipitation data from 51 meteorological stations in the Pearl River basin from 1993 to 2022 and used statistical methods such as Mann-Kendall test and ordinary Kriging interpolation to analyze the changes in temperature and precipitation. Based on the shared socioeconomic pathway 1 〔SSP1-2.6 （with a radiative forcing level of 2.6 W/m² by 2100）〕 scenario， extreme climate events during 2023—2050 were predicted. ［Results］ ① The temperature showed an upward trend temporally， and precipitation also showed an upward trendexcept annually and during summer. ② Spatially the temperatures were relatively uniform in winter but exhibited significant regional differences in the other three seasons. Overall， precipitation was higher in the east and southeast and lower in the west and northwest. ③ Under the SSP1-2.6 scenario， the maximum daily temperature extremes and minimum daily temperature extremes and the maximum number of consecutive rainless days showed a non-significant upward trend， and the precipitation on extremely wet days showed a non-significant downward trend during 2023—2025. ④ Spatially， the maximum daily temperature decreased from the central region to the surrounding areas， and extremely high values of precipitation on extremely wet days were observed in the central-southern region during 2023—2025. The minimum daily temperature extremes decrease from the southeast to the northwest， whereas the maximum number of consecutive rainless days decreased from the central-southern regions to other areas. ［Conclusion］ From 1993 to 2022 the Pearl River basin has shown a ‘warm and humid’ trend； Under the SSP1-2.6 pathway， extreme climate events will be mere complex hybrid and locally prominent during 2023—2025.

Abstract:［Objective］ Soil moisture spatiotemporal dynamics in fixed sand-dunes （planted with Hedysarum scoparium） in eastern Yellow River sandy land in Ningxia Hui Autonomous Region were investigated， to provide scientific insights for sustainable desertification control and effective evaluation of sand stabilization measures. ［Methods］ The HYDRUS-1D model was employed to simulate the vertical distribution （0—150 cm profile） and temporal variations in soil moisture in fixed dunes. The model performance in eastern sandy land of Yellow River in Ningxia was evaluated using the coefficient of determination （R²）， root mean square error （RMSE）， and relative error （RE）. ［Results］ ① Rainfall infiltration exhibited threshold-dependent characteristics： infiltration depth was limited to <5 cm when precipitation <2.2 mm， 5—15 cm for 3.6—8.2 mm rainfall， and 15—30 cm for 10.8—22.8 mm rainfall. ② The model demonstrated satisfactory performance in simulating soil-water content across most depths （calibration R²=0.756， validation R²=0.773； RMSE=0.071% and 0.064%； RE=0.030% and 0.032%）. Although surface （5 cm） and deep layer （125 cm） simulations showed lower accuracy， intermediate layers （15， 30， 50， and 80 cm） achieved better results （R²=0.571—0.849， RMSE=0.0001%—0.042%）. ［Conclusion］ The infiltration patterns varied significantly across rainfall events， showing a positive correlation between the amount of precipitation and infiltration depth. The HYDRUS-1D model proved suitable for simulating the soil moisture dynamics in this arid sandy ecosystem， with simulations closely matching field observations.

Abstract:［Objective］ Scientifically estimate the value of ecosystem services in the Sanjiangyuan region to provide a scientific basis for understanding the ecological asset reserves and ecological security safeguards of the watershed. ［Methods］ Using the improved equivalent factor method， substitute engineering method， and substitute cost method， we scientifically assessed the total value of ecosystem services and the value of individual ecological service functions in the Sanjiangyuan region. By employing remote sensing and spatial statistical analysis techniques， we examined the spatial distribution characteristics of ecosystem service values in this region and identified its core functional zones. ［Results］ ① The total value of ecosystem services in the Sanjiangyuan region amounts to 246.485 billion yuan. Among these， water conservation services hold the highest value at 93.401 billion yuan， accounting for 38% of the total and consistent with the region’s designation as China’s ‘water tower.’ Climate regulation and soil conservation follow， comprising 33% of the total value. Habitat protection and landscape aesthetics contribute 21% of the total value. Air purification services showed the lowest value， accounting for only 8% of the total. ② The values of water conservation， soil retention， habitat protection， and landscape aesthetics exhibited a ‘higher in the north， lower in the south’ pattern， while climate regulation and air purification values demonstrated an ‘higher in the east， lower in the west’ distribution characteristic. ［Conclusion］ Yushu Xizang Autonomous Prefecture and Guoluo Xizang Autonomous Prefecture serve as vital climate regulation zones and soil conservation areas. Efforts to advance forest and grassland ecological protection and restoration should be sustained， establishing a comprehensive system for soil and water erosion control to continuously enhance soil retention capacity. Haixi Mongol and Xizang Autonomous Prefecture， Yushu Xizang Autonomous Prefecture， and Guoluo Xizang Autonomous Prefecture are vital water conservation and recharge areas. Efforts should be intensified to protect wetland water bodies and reduce the risk of contamination. Different river basins should strengthen coordinated governance and scientifically plan landuse.

Abstract:［Objective］ The performance of ecological compensation policy implementation was scientifically evaluated in the Three-River-Source National Park. Existing problems and actual ecological benefits were analyzed during the implementation process in order to provide a decision-making basis for optimizing government ecological compensation policies. ［Methods］ Based on the theory of public value， a comprehensive evaluation index system covering the two dimensions of the perception of the policy implementation process and ecological outcomes was constructed from the perspective of herders. The implementation process was assessed based on four core dimensions： fairness， participation， efficiency， and sustainability. The ecological outcomes were measured using five indicators： policy compliance rate， vegetation growth conditions， soil and water conservation improvement rate， vegetation cover change， and spatial evenness. The Analytic Hierarchy Process （AHP） was used to determine the weights of each indicator. ［Results］ ① The overall performance score of the policy implementation process in the Three-River-Source National Park was 0.646， indicating relatively good performance； ② There were certain differences between counties， with Zhiduo and Zaduo counties scoring relatively low， while the overall ecological outcome performance score was 0.623， which was considered good； ③ The performance differences among counties suggest that more attention had been paid to ecological outcomes， while less emphasis had been placed on the management of the implementation process. ［Conclusion］ Future improvements in ecological compensation policies should emphasize the implementation process to better coordinate policy execution and ecological outcomes， ultimately enhancing the public value of ecological protection and the wellbeing of herders.

Abstract:［Objective］ This study aims to analyze the evolution characteristics of saline-alkali land governance policies in the Xinjiang Uyghur Autonomous Region from 1986 to 2025， with the goal of providing scientific guidance for the region’s future saline-alkali land management and utilization efforts. ［Methods］ Based on the evolution of policy content and identification of key node， 160 publicly released saline-alkali land management policies in Xinjiang were divided into different stages since 1986. Text mining and quantitative analysis of the policies at each stage were conducted using word frequency analysis and social semantic network analysis tools in the ROST Content Mining System V6.0. ［Results］ ① The evolution of saline-alkali land management policies in Xinjiang underwent three distinct stages： initial planning （1986—2013）， targeted remediation （2014—2021）， and comprehensive utilization （2022—2025）. ② Each stage exhibited some distinctive characteristics： the initial planning stage focused on soil improvement and systematic planning； the targeted remediation stage emphasized farmland quality enhancement and ecological environmental protection； and the comprehensive utilization stage concentrated on integrated saline-alkali land use and high-standard farmland construction. ③ Over time， policies evolved toward comprehensive and refined approaches， with management objectives shifting toward diversified utilization and sustainable development of saline-alkali land. The management process has increasingly emphasized the balance between ecological protection and land management， with governance frameworks becoming more mature and management measures more diversified. ［Conclusion］ Based on the stage division of policy content and text mining methods， this study systematically reveals the development and evolution characteristics of saline-alkali land management policies in Xinjiang， demonstrating high applicability and operational feasibility.

Abstract:［Objective］ The comprehensive benefits of desertification prevention and control in Shaanxi Province over the years were monitored and evaluated， in order to provide a scientific reference for the formulation of relevant policies and development plans in Shaanxi Province， as well as the protection， improvement， and rational utilization of resources to achieve sustainable development. ［Methods］ Based on monitored data related to artificial afforestation and grass planting in desertification control in Shaanxi Province from 2011 to 2022， and in accordance with relevant standards and previous research experience， corresponding indicators and methods for calculating ecological， economic， and social benefits were selected for comprehensive evaluation. ［Results］ The cumulative area of artificial afforestation promoted in desertification land management in Shaanxi Province reached 8.36×10⁵ hm² hectares. During the period from 2011 to 2022， the comprehensive prevention and control of desertification played an important role in blocking dust， windbreak and sand fixation， improving soil nitrogen and phosphorus retention， increasing soil organic matter retention， conserving water sources， fixing carbon and releasing oxygen. At the same time， outstanding economic benefits were achieved in eight aspects： carbon sequestration forests， forage grass， cost saving from afforestation and grass planting， seeds， fruits， agroforestry， complementary “forest （grass）-solar” systems， ecotourism and forest-based wellness programs. The cumulative employment reached 15 000 people， and the cumulative income of farmers reached 800 million yuan. ［Conclusion］ The comprehensive prevention and control of desertification in Shaanxi Province has significant benefits in improving the natural environment， increasing employment opportunities， absorbing surplus labor， alleviating employment pressure， and promoting harmonious coexistence and development between humans and nature.

Abstract:［Objective］ The spatiotemporal evolution characteristics and influencing factors of flood disasters in Pakistan were analyzed， in order to provide scientific references for flood risk analysis and management. ［Methods］ Based on 143 typical flood events recorded by the Dartmouth Flood Observatory （DFO） from 1985 to 2021， this study integrated multi-source spatial datasets， including ERA5-Land precipitation， digital elevation model （DEM）， land use， population density， and gross domestic product （GDP）. The temporal variation， spatial distribution， gravity center migration， and directional evolution of flood disasters were analyzed using methods such as anomaly analysis， the gravity center model， and the standard deviational ellipse. The optimal parameter-based geodetector （OPGD） model was employed to quantitatively identify the dominant influencing factors and their interactive effects on the spatiotemporal distribution of flood disasters. ［Results］ Flood disasters in Pakistan entered a period of high occurrence from 2005 to 2010， with the frequency reaching a historical record high in 2007. The disasters exhibited spatial evolutionary characteristics， shifting from widespread distribution to high-density and high-severity concentration in the middle and upper reaches of the Indus River. The disaster centroid migrated northward， the primary distribution axis aligned in a north-south direction， and the spatial pattern became increasingly clustered. The geodetector analysis revealed that precipitation-related factors （Rx_5d， R_20mm， and Rx_1d） possessed strong explanatory power， with most combinations of factors exhibiting significant synergistic effects. ［Conclusion］ Flood disaster risks in Pakistan steadily increased， characterized by shifting disaster centroid and distribution orientation， while the spatial pattern becomes increasingly concentrated. Extreme precipitation events serve as the key trigger of flood disasters， while the interaction between topographic factors and precipitation-related factors critically shapes the spatial heterogeneity of flood occurrence.

Abstract:［Objective］ The spatial distribution of soil erosion in the northern foothills of the Qinling Mountains （Xi’an section） was examined to identify the key areas requiring erosion control and management. The aim was to provide a scientific basis and decision support for controlling regional water and soil loss and implementing ecosystem restoration projects. ［Methods］ The spatiotemporal evolution of and mechanisms driving soil erosion in the in northern foothills of Qinling Mountains （Xi’an section） from 2010 to 2023 were systematically evaluated using the RUSLE model and geographic information system spatial analysis technology. ［Results］ ① The soil erosion in the region was mainly mild or slight； the proportion of the area experiencing mild erosion intensity or below increased over time， whereas that of the areas with moderate or more serious erosion decreased， shifting toward mild and slight soil erosion. ② The grassland and farmland was mainly converted into forest land from 2010 to 2023. The average soil erosion modulus decreased for different land use types： the forest and construction land areas increased， and the farmland and grassland areas decreased. ③ The rainfall erosion force and soil erosion distribution were consistent； the erosion intensity with elevation and slope ranked as follows： strong > moderate > extremely strong > intense > slight > mild. ［Conclusion］ Soil erosion on the northern foothills of the Qinling Mountains （Xi’an section） has spatially and temporally become less severe. However， the management of the soil in certain areas still needs to be strengthened due to the fragile geological environment， intense human activities and the impact of climate change. Various management measures， such as vegetation restoration， hedgerows， field ridges， and straw mulching， should be implemented for controlling soil erosion.

Abstract:［Objective］ The dynamic characteristics and driving factors of ecological environmental quality in the Mu Us sandy land are investigated， aiming to provide a scientific basis for the restoration and sustainable development of this ecologically fragile area. ［Methods］ Based on the Google Earth Engine （GEE） platform， MODIS remote sensing data from 2000 to 2023 were used to construct the remote sensing ecological index （RSEI）. Through breaks for additive season and trend （BFAST） abrupt change detection and geodetector method， the spatiotemporal evolution characteristics and driving factors of ecological environmental quality in the Mu Us sandy land were systematically analyzed. ［Results］ ① The RSEI model had good applicability in the Mu Us sandy land， with the principal component contribution rates all exceeding 70%， effectively reflecting the evolution process of ecological environment in the study area. ② The BFAST detection results showed that the ecological environmental quality in the study area exhibited significant spatial heterogeneity from 2000 to 2023. The monotonic increase type （without abrupt change） accounted for 43.4% of the total sandy land area， primarily distributed in the eastern part of the sandy land， while the monotonic decrease type （without abrupt change） accounted for 33.6%， mainly located in the western and southern marginal areas. The spatial distribution of RSEI abrupt change years demonstrated a pattern of “localized clustering and overall dispersion”， with 2019 being the year with the highest frequency of abrupt changes. ③ The geodetector analysis showed that soil moisture was the dominant factor affecting the spatial differentiation of ecological environmental quality. Meanwhile， in 2019， the year with the most frequent abrupt changes， the interaction between temperature， precipitation， and other factors was significantly enhanced. ［Conclusion］ The ecological environment evolution patterns of the Mu Us sandy land are driven by both climate change and human activities. Regional ecological restoration and policy formulation should consider the influence of multiple factors.

Abstract:［Objective］ The trade-off and coordination between agricultural ecological efficiency and economic resilience in arid regions and their driving factors were identified， in order to provide a scientific basis for achieving regional sustainable development and win-win management decisions for agricultural development and ecological protection in Xinjiang. ［Methods］ Agricultural ecological efficiency levels and agricultural economic resilience in 14 prefectures of Xinjiang Uygur Autonomous Region from 2010 to 2022 were measured. Spearman’s rank correlation analysis， production possibility frontier （PPF）， and trade-off intensity index were employed to quantitatively analyze the trade-off and coordination relationships between efficiency and resilience. Geographically weighted regression （GWR） was applied to analyze the influencing factors of the efficiency-resilience trade-off and coordination relationships in different regions. ［Results］ ① The agricultural economic resilience in Xinjiang demonstrated a rapid growth trend over time and a spatial distribution pattern of “south > north”. Agricultural ecological efficiency showed an increasing trend， with a spatial pattern of “south > north”. ② Output and resistance demonstrated significant coordination， while output and recovery exhibited significant trade-off. The PPF curves of input—resistance and output—recovery were “concave-down—convex-up” in shape， with most of the corresponding combinations in their optimal configurations. ③ The trade-off relationship between efficiency and resilience was strengthened by all influencing factors， with the overall order being： fiscal expenditure on agriculture， forestry， and water resources > fiscal expenditure on science and technology > total output value of agriculture， forestry， animal husbandry， and fishery> total investment in environmental pollution control. Additionally， the influencing factors enhanced the coordination relationship between efficiency and resilience in the following descending order： total investment in environmental pollution control> fiscal expenditure on science and technology > total output value of agriculture， forestry， animal husbandry， and fishery> fiscal expenditure on agriculture， forestry， and water resources. ［Conclusion］ All prefectures in Xinjiang should formulate region-specific policies for the trade-off and coordination between agricultural ecological efficiency and agricultural economic resilience， thereby achieving sustainable development in arid regions.

Abstract:［Objective］ The spatiotemporal evolution of urban ecological security patterns under the influence of urbanization was researched， the impacts of human activities on ecological connectivity were analyzed， and corresponding strategies to optimize the ecological network were proposed to provides theoretical support and decision-making references for urban ecological protection and sustainable spatial governance. ［Methods］ Taking Kunming City as a case study， the remote sensing ecological index （RSEI） was employed to assess regional habitat quality. By integrating the XGBoost machine learning model with SHAP interpretability analysis tools， the main driving factors influencing the spatial pattern of RSEI were identified. Based on these driving factors， an ecological resistance surface was constructed. Subsequently， through the application of morphological spatial pattern analysis （MSPA）， landscape connectivity index （LCI）， and circuit theory， a comprehensive ‘point-line-plane’ ecological security pattern was established. ［Results］ From 2000 to 2023， Kunming’s ecological security pattern underwent significant changes. Although the area of ecological sources increased by 1 258.50 km²， representing an expansion of the total ecological source area， the number of ecological corridors decreased by 23， with a total length reduced by 201.58 km. Furthermore， the number of ecological pinch points decreased by 14， while ecological barrier points increased by 4. These alterations seriously affected the connectivity of the ecological network and the free migration capacity of species. Due to urban expansion and intensified human activities， the Dianchi Lake periphery emerged as the most severely impacted zone， exhibiting the highest ecological resistance values and facing a high risk of connectivity degradation. ［Conclusion］ To counter urbanization challenges， Kunming should strengthen ecological source protection， rehabilitate key ecological corridors， reduce human interference with the ecological network， and implement stricter ecological protection measures in the Dianchi Lake periphery to mitigate the negative impacts of urbanization on the ecosystem.

Abstract:［Objective］ The spatiotemporal variation characteristics of vegetation water use efficiency （WUE） in the Qingshui River basin are explored， and the main factors affecting vegetation WUE were analyzed， so as to provide a scientific basis for vegetation conservation and the sustainable utilization of water resources in the river basin. ［Methods］ The Qingshui River basin was selected as the study area. Using multi-source data such as MODIS remote sensing data， meteorological data， and land use information， the spatiotemporal evolution characteristics of vegetation WUE and its influencing factors in the Qingshui River basin from 2001 to 2022 were estimated and analyzed using the methods of trend analysis， Hurst index， coefficient of variation， correlation analysis， and partial derivatives. ［Results］ ① The overall spatial pattern of vegetation WUE in the river basin exhibited a “higher in the south and lower in the north” distribution， with an interannual variation trend of 0.005 g/（kg · a）. ② The vegetation WUE in the river basin mainly showed an increasing trend， with areas accounting for 76.19% of the total basin area. ③ The vegetation WUE in the river basin was relatively stable， covering 83.94% of the total basin area. The mean Hurst value was 0.48， indicating weak anti-persistence in vegetation WUE across the basin. ④ The correlation between vegetation WUE and leaf area index （LAI） was the highest， with an average coefficient of 0.54. Natural factors contributed less to WUE variation than human activities which were the primary drivers of the WUE increase. ［Conclusion］ The vegetation WUE in the river basin shows spatial heterogeneity and is mainly influenced by human activities. Therefore， it is crucial to strengthen ecological protection to improve the vegetation WUE in the river basin.

Abstract:［Objective］ The coupling and coordination relationship between green transition of farmland use and green total factor productivity of grain under the dual constraints of resources and environment， as well as the spatiotemporal evolution of driving factors were analyzed， in order to provide theoretical support for agricultural green transition in the region. ［Methods］ Based on arable land use and grain production data， combined with carbon emissions and non-point source pollution coefficients， the spatiotemporal evolution trend of the coupling coordination level of green transition of farmland use and green total factor productivity of grain in the Tarim River basin from 2000 to 2021 was analyzed using the entropy method， Super-EBM model， and coupling coordination degree model. The driving factors were analyzed using spatiotemporal geographically weighted regression model. ［Results］ ① During the study period， the green transition of farmland use and green total factor productivity of grain in various prefectures in the Tarim River Basin were generally in a highly coupled stage. The coordination level was generally low， and the coordination type improved from general to good coordination. The overall coupling coordination showed an upward trend， with the average value rising from 0.643 to 0.872， an increase of 35.6%. The coupling coordination type progressed from primary to good coordination. ② Spatially， the coupling coordination level showed a distribution pattern of high in the middle and low in the east and west， with regional differences showing a fluctuation trend. ③ The driving factors showed stage-specific characteristics： natural factors turned from negative to positive and fluctuated， economic factors turned from positive to negative drivers， and social factors experienced alternating positive and negative fluctuations. ［Conclusion］ It is recommended that the Tarim River basin embraces the concept of green agricultural development， implements spatially adaptive governance strategies， promotes collaborative innovation in technology and institutions， and drives the coupled and coordinated development of green transition of farmland use and green total factor productivity of grain.

Abstract:［Objective］ The spatial differentiation and driving factors of ecosystem service value under the topographic gradient characteristics of Taohe River basin were explored in order to provide scientific support for promoting ecological protection and sustainable social and economic development in the basin. ［Methods］ Based on six phases of land-use remote sensing data （1993—2023） and integrated an ecosystem service value （ESV） assessment model， terrain distribution index， and geographical detector method to systematically explore the spatial and temporal evolution laws， topographic gradient characteristics， and driving mechanisms of ESV over the past 30 years. ［Results］ ① The Taohe River basin features a typical stepped topographic gradient distribution， with 84.99% of its area concentrated in gradients of 2 to 7. The dominant land-use types across gradients 1—9 follow a sequential transition： construction land-water bodies-cropland-grassland-forestland-forestland-forestland-unused land-unused land. ② The total ESV of Taohe River basin during the research period increased by 6.39×10⁷ yuan （a 2.36% rise）. Its spatial distribution is characterized by a gradient differentiation involving initial increases and then decreases along the terrain gradient from low to high. High ESV values were predominantly distributed in gradients 5 and 7 （adjacent to the Qinghai-Xizang Plateau）， whereas low values were clustered in gradient 1 and gradient 9 regions within the southwestern Loess Plateau. ③ ESV gradient differentiation emerged from the synergistic interaction of natural geographic and socioeconomic factors， with elevation （DEM） serving as the dominant explanatory factor （q=0.491）. Its interactions with slope and land-use intensity demonstrate two-factor enhancement effects. ［Conclusion］ The ESV in the Taohe River basin initially increased and then decreased with rising terrain gradients. From 1993 to 2023， the low-gradient zone exhibited negative ESV growth， whereas the medium-and high-gradient zones featured sustained growth and stabilization. The spatial differentiation of ESV was primarily driven by natural factors. On the basis of these findings， we recommend strictly controlling construction land expansion and enhancing aquatic ecology restoration in low-gradient zones， promoting ecological agriculture and cultivated land protection in medium-gradient zones， and reducing human disturbance while strengthening unused land management in high-gradient zones.

Abstract:［Objective］ This study aims to identify the spatial conflict patterns of land use within the Southern Anhui International Cultural Tourism Demonstration Zone and to investigate their correlation with land use change， in order to provide a scientific basis for regional coordinated and sustainable development. ［Methods］ A land use conflict measurement model based on landscape pattern indices was constructed， and quantitative analyses to characterize land use change， land use conflict， and land use intensity from 2000 to 2023 were conducted combining the geographic detector method to examine the driving mechanisms. ［Results］ ① From 2000 to 2023， land use within the zone showed a trend of cultivated land and forest land decreasing， while construction land expanded. Land conversion hotspots concentrated in the northern riverside plains and southern intermountain basins. Forest land maintained its ecological substrate function through bidirectional conversions. ② The level of land use conflict exhibited a spatial pattern of higher values in the north and lower values in the south， but the overall trend decelerated. Land use intensity decreased at the same time， resulting in a differentiated pattern characterized by low-intensity strips in mountainous areas and high-intensity nodes in plains. ③ Spatial synergy between land use conflict and land use intensity significantly strengthened during the study period. The overall Moran’s I index increased continuously， and high-value agglomeration areas overlapped with hotspots of construction land expansion. ④ Slope emerged as the dominant natural environmental factor constraining the conflict pattern. The interaction level between land use intensity and GDP was comparable to that between land use intensity and natural environmental factors， which revealed a trend where economic development intentions challenge natural constraints. This dual-driver effect was supported by the finding that 56.6% of lost cultivated land was converted for urban construction. ［Conclusion］ While the overall level of land use conflict decreased within the Southern Anhui International Cultural Tourism Demonstration Zone， spatial differentiation intensified because of both natural and economic factors. Strict control of development in the northern plains through territorial spatial use regulation remains necessary. At the same time， coordination of ecological protection and intensive land use across the entire region is required to drive high-quality development of the International Cultural Tourism Demonstration Zone.

Abstract:［Objective］ The spatiotemporal variations of vegetation coverage and its driving mechanisms at Badong County， Hubei Province， Three Gorges reservoir area were analyzed， in order to provide scientific references for vegetation restoration， soil and water conservation， and ecological protection. ［Methods］ Based on MODIS NDVI data， the spatiotemporal dynamics of fractional vegetation coverage in Badong County from 2013 to 2023 was analyzed and the differentiation characteristics of vegetation coverage influenced by topography， geology， and climate factors was explored. Furthermore， the geodetector and random forest models were employed to identify dominant factors and their interaction effects. ［Results］ ① From 2013 to 2023， vegetation coverage at Badong County exhibited a fluctuating upward trend at a rate of 0.001 7/a， with overall high coverage levels. ② Vegetation coverage showed distinct spatial differentiation across influencing factors： it correlated positively with the spatial variation of elevation， slope， and annual precipitation， but negatively with mean annual temperature. It was also influenced by aspect， lithology， vegetation type， and soil type. ③ Geodetector analysis identified elevation and mean annual temperature as primary drivers （explanatory power >40%）， while lithology， geomorphological type， and annual precipitation were secondary factors. Multi-factor interactions demonstrated synergistic enhancement， with elevation and lithology jointly explaining 55% of variation. Random forest model further validated the importance ranking of dominant predictors： elevation > mean annual temperature > lithology > annual precipitation. ［Conclusion］ The geodetector and random forest model jointly reveal elevation as the core driver of fractional vegetation coverage changes at Badong County in Three Gorges reservoir area during 2013—2023， followed by mean annual temperature， lithology， and precipitation.

Abstract:［Objective］ The current cultivated land status and driving factors of cultivated land development in the Gansu Province were investigated to provide scientific support for formulating targeted policies promoting cultivated land protection and sustainable agricultural development. ［Methods］ Using 14 prefecture-level cities in Gansu Province as research units， this study quantified the intensity of cultivated land development and employed methods including the Theil Index， standard deviational ellipse， and gray correlation analysis to reveal spatiotemporal pattern evolution characteristics and influencing factors of cultivated land development intensity in Gansu Province from 2004 to 2023. ［Results］ ① The intensity of cultivated land development in Gansu Province had fluctuated but increased overall. Spatial distribution exhibited significant heterogeneity， presenting the pattern ‘higher in the east， lower in the west； higher in the south， lower in the north.’ High-intensity areas were concentrated in the middle and eastern parts of the Yellow River basin， whereas low-intensity areas were distributed in the southwestern and western regions. ② The spatial differentiation of cultivated land development breadth in Gansu Province showed a pattern of ‘higher in the east， lower in the west； higher in the south， lower in the north，’ with a continuous decline over time. Development depth followed a north-south transition of high-value areas with narrowing low-value zones. The development frequency presented a ‘central-high-peripheral-low’ pattern with increasing inter-city disparities. ③ The intensity of cultivated land development in Gansu Province had formed relatively stable spatial agglomeration characteristics. The center of gravity had shifted toward northwest as a whole， and the area of the standard deviational ellipse had increased from 135， 816.83 km² to 144， 192.68 km²， indicating increased spatial dispersion. ④ The total Theil index of cultivated land development fluctuated slightly between 0.2180 and 0.1680， with inter-group differences （59.83%—70.56%） dominating regional variations. The Hexi Corridor contributed 45.02%—58.50% to intergroup differences， serving as the primary driver of variations in intensity in Gansu Province. ⑤ Differentiation in cultivated land development intensity in Gansu Province was not determined by a single factor， however， was jointly driven by multiple factors， including natural environmental and socioeconomic factors. Natural environmental factors played a decisive role in development intensity， breadth， and depth， whereas socioeconomic factors played a decisive role in frequency. ［Conclusion］ The change in cultivated land development intensity in Gansu Province is a dynamic process dominated by natural environmental factors and assisted by socioeconomic factors. It is characterized by obvious spatial heterogeneity and agglomeration， with a fluctuating upward trend over the examined years.