Abstract:[Objective] The effects of acid rain on the leaching loss of base ions and molybdate ions in purple soil were analyzed in order to provide a scientific basis for understanding fertility changes and nutrient management in purple soil under acid deposition conditions. [Methods] Taking the calcareous purple soil developed from the parent material of the Jurassic Penglaizhen Formation （J₃ p） as the research object， five leaching solution treatments were established to simulate acid rain with pH values of 2.5 （T₁）， 3.5 （T₂）， 4.5 （T₃）， 5.6 （T₄）， and 7.0 （deionized water， CK）. [Results] ① The pH value of the leachate showed a trend of rapid decline followed by gradual stabilization. In the early stage， the pH value of the leachate decreased by 6.17%， 8.05%， 3.75%， 3.70%， and 2.01% for T₁， T₂， T₃， T₄， and CK， respectively. In the later stage， it stabilized within a range of ±0.2 of the pH value of the 10th leachate. After two years of simulated acid rain leaching， the pH value of the leachate in T₁， T₂， T₃， and T₄ decreased by 0.22， 0.39， 0.32， and 0.29， respectively. Compared with the CK， the soil pH value decreased by 0.67， 0.62， 0.56， and 0.46， respectively. ② The contents of base ions in the leachate exhibited a fluctuating decline with increasing leaching cycles， and the total leaching amounts generally decreased as the pH value of the leaching solution increased. The total leaching amounts of K⁺ followed the order： T₁ > T₃ > T₂ > T₄ > CK. The total leaching amounts of Na⁺ followed the order： T₁ > CK > T₂， T₃， T₄. The total leaching amounts of Ca²⁺ followed the order： T₁ > T₂， T₃ > T₄ > CK. The total leaching amounts of Mg²⁺followed the order： T₁ > T₃ > T₄ > CK， T₂. The total leaching loss amounts of base ions were in the order： Ca²⁺> Mg²⁺> Na⁺> K⁺. ③ The Mo⁴⁺content in the leachate showed a fluctuating decreasing trend， and the total leaching amount generally increased with increasing pH value， following the order： CK （59.22 μg） > T₄ （56.11 μg） > T₃ （52.42 μg） > T₁ （41.03 μg） > T₂ （39.56 μg）. Mo⁴⁺ was positively correlated with pH value and negatively correlated with K⁺and Ca²⁺. ④ A synergistic relationship was observed between the leaching loss amounts of base ions and Mo⁴⁺. As the leaching loss of Mo⁴⁺ increased， base ions first increased and then decreased. The total leaching loss amounts of K⁺， Na⁺， Ca²⁺， and Mg²⁺ reached their peaks when the total leaching loss of Mo⁴⁺ reached 46.11， 46.11， 44.51 μg， and 46.11 μg， respectively. [Conclusion] The T₁ treatment of simulated acid rain （pH = 2.5） results in the highest leaching loss of base ions but the lowest leaching loss of molybdenum. The leaching loss amounts of both base ions and the trace element molybdenum in the T₃ treatment （pH = 4.5） are at relatively high levels， indicating more severe nutrient loss.

Abstract:[Objective] The mechanisms underlying the responses of vegetation coverage measures to hydrothermal patterns and temporal stability of surface soil on Benggang collapsing gully walls were analyzed， in order to provide a theoretical basis and predictive parameters for evaluating the efficacy of ecological restoration of stable Benggang collapsing gully walls. [Methods] Collapsing gully walls in Hetian Town， Changting County， Fujian Province， were subjected to two treatments， namely， planting Paspalum wettsteinii on the gully walls （grass-growing treatment） and maintaining the original bare collapsing gully walls （control）. To compare differences in the spatial distribution characteristics of soil water and heat under the two treatments， as well as indicators of soil moisture temporal stability， we monitored the dynamic changes in soil moisture and temperature in the 0—20 cm soil surface layer. [Results] Throughout the period of monitoring， the average soil temperature under the grass treatment with P. wettsteinii was 20.93 ℃， which was significantly lower than that of the bare control soil （22.26 ℃）. Moreover， the ranges of temperature fluctuation on the upper and lower slopes under grass cover （23.76 ℃ and 21.95 ℃， respectively） were both lower than corresponding values for the bare slope （25.32 ℃ and 26.36 ℃， respectively）. In addition， the annual average soil moisture content under the grass treatment （18.77 g/kg） was approximately 38.11% higher than that of the bare control （13.59 g/kg）. Spearman rank correlation analysis revealed that the mean correlation coefficient （ρ） of soil moisture under grass cover （0.41） was significantly higher than the 0.18 value obtained for bare land， thus indicating enhanced spatial consistency. However， vegetation coverage was found to alter soil moisture cycling， increasing the frequency of dry-wet alternations， as indicated by higher values for the mean relative difference （MRD）， standard deviation， and temporal stability index （ITS） under the grass treatment compared with those of the bare land control. Specifically， in response to the grass treatment， we obtained values of 19.27%， 22.57%， and 29.68% for the average MRD， standard deviation， and ITS respectively， on the downslope， whereas on the upslope， the corresponding values were 10.48%， 12.47%， and 16.29%. In contrast， under the control treatment， we obtained MRD， standard deviation， and ITS values of -13.43%， 16.05%， and 20.93%， respectively， on the upslope， and corresponding values of -16.32%， 9.33%， and 18.80% on the downslope. [Conclusion] By reducing temperature， increasing moisture content， and enhancing spatial similarity， the grass-growing treatment assessed in this study contributed to considerable improvements in the water and heat dynamics of the surface soil on collapsing gully walls. However， this treatment also intensified short-term fluctuations in soil moisture and reduced soil temporal stability.

Abstract:[Objective] The soil improvement potential of oat （Avena sativa） biological sand barriers in the restoration of alpine sandy land were evaluated in order to clarify their regulatory mechanisms on soil carbon （C）， nitrogen （N）， and phosphorus （P） nutrients and their ecological stoichiometric characteristics during a two-year planting period， and provide theoretical and practical guidance for the ecological restoration of desertified grassland in alpine regions. [Methods] Typical alpine mobile sand dunes in Qinghai Lake basin were selected as the study area， where oat biological sand barrier plots were established. Soil samples were collected at four key time points over a two-year continuous growing period： before sowing （T₁）， at the end of the first growing season （T₂）， at the beginning of the second growing season （T₃）， and at the end of the second growing season （T₄）. Soil carbon， nitrogen， phosphorus contents and their ecological stoichiometric characteristics were determined at different growth stages. [Results] The oat biological sand barriers significantly increased the soil organic carbon （SOC） and total nitrogen （TN） contents in the surface soil （0—20 cm）， while the increase in total phosphorus （TP） was relatively slow. In the T₄ period， the SOC and TN in the surface soil increased by approximately 18.2% and 29.3%， respectively， compared to the T₁ period， and the SOC and TN in the deep soil （20—40 cm） increased by 56.8% and 27.0%， respectively. The available nitrogen （AN） and available phosphorus （AP） contents in the surface soil increased by 19.8% and 72.7%， respectively， in T₄ compared to T₁， while soil pH value decreased by approximately 15.0%. With increasing planting duration， the C/N and C/P ratios showed a trend of first increasing and then decreasing， while the N/P ratio showed a gradually increasing trend. Mantel test results indicated that SOC， TN， TP， and pH value were the main factors influencing the stoichiometric characteristics. [Conclusion] The oat biological sand barriers effectively enhance soil organic matter level and nutrient supply， promoting the cycling of elements. Additionally， they optimize the ecological stoichiometric structure of C， N， and P， alleviate nutrient limitations， and enhance soil ecological functions. Furthermore， the restoration benefits accumulate progressively over the two-year planting period， demonstrating potential for long-term soil quality restoration.

Abstract:[Objective] The influencing mechanisms of different soil and water conservation tillage measures on runoff and sediment yield of slope cropland in the black soil region under natural rainfall conditions were analyzed， in order to provide a scientific basis and technical support for the prevention， control， and management of soil erosion in the black soil region in northeast China. [Methods] Typical slope cropland in the black soil region of Heilongjiang Province was selected as the research object. Runoff plots were established， with traditional downslope ridging as the control. The characteristics of runoff and sediment yield under four soil and water conservation tillage measures-cross-slope ridging， cross-slope ridging + plant hedges， straw return to the field， and ridge field-were analyzed to investigate the patterns of runoff and sediment reduction under different soil and water conservation tillage measures. [Results] ① All four soil and water conservation tillage measures-cross-slope ridging + plant hedges， cross-slope ridging， straw return to the field， and ridge field-could reduce the runoff and sediment yield of slope cropland. Compared with downslope ridging， runoff decreased by 74%， 67%， 29%， and 64%， respectively， and sediment yield decreased by 88%， 87%， 67%， and 66%， respectively. ② The measures of cross-slope ridging + plant hedges showed the most significant rates of runoff and sediment reduction （p<0.05）. ③ The duration of runoff and sediment yield from the slope cropland under the cross-slope ridging + plant hedge measure was the shortest. ④ The runoff volume and sediment yield from the slope cropland showed a significant positive correlation （p<0.01）. [Conclusion] The cross-slope ridging plant hedge measure demonstrates significant runoff and sediment reduction rates， and it is recommended for wider application in this region.

Abstract:[Objective] The effects of different plantation types on understory vegetation community structure， species diversity， and soil physicochemical properties in Pisha sandstone area were analyzed， in orderto select suitable tree species for constructing soil and water conservation forests and provide a scientific basis for vegetation restoration and species diversity conservation in Pisha sandstone area. [Methods] Four typical plantation types （Caragana korshinskii， Prunus sibirica， Hippophae rhamnoides and Pinus tabuliformis forest） in Baojiagou watershed of Nuanshui Township， Jungar Banner， Ordos City， Inner Mongolia Autonomous Region， were selected as the research objects， with natural grassland （CK） as the control. Through field surveys， sampling， and laboratory experiments， the relationships among understory herbaceous plant community composition， species diversity， and soil physicochemical properties the natural grassland and the four typical plantations were investigated. [Results] ① The understory herbaceous vegetation in the study area comprised 23 species from 18 genera and 10 families. The C. korshinskii forest had the highest number of understory herbaceous species， with a total of 22. The understory herbaceous plants in the four plantations were mainly composed of species from the Asteraceae， Gramineae， and Fabaceae families. ② The coverage， biomass， Margalef richness index， and Shannon-Wiener diversity index of the understory herbaceous layer under the C. korshinskii forest were significantly higher than those under other vegetation types （p<0.01）. ③ The soil moisture content， soil organic matter， and total nitrogen content under the C. korshinskii forest were significantly higher than those under other vegetation types （p<0.01）. Soil organic matter and total nitrogen exhibited a surface aggregation effect. ④ Soil organic matter and saturated hydraulic conductivity were the dominant factors affecting the species diversity of the understory herbaceous layer in the plantations， while topography was a secondary factor. [Conclusion] C. korshinskii is the preferred tree species for constructing soil and water conservation forests in the Pisha sandstone area of Jungar Banner. It plays a dual role in maintaining species diversity and improving soil quality.

Abstract:[Objective] The soil and water conservation benefits of different slope gradients and vegetation patterns in dry-hot valleys were analyzed in order to provide a reference for selecting soil and water conservation patterns in the Yuanmou dry-hot valley. [Methods] Experimental plots with slopes of 5° and 10° were established to conduct in-situ monitoring of runoff and sediment under three typical vegetation patterns： Heteropogon contortus， H. contortus + Phyllanthus emblica， and H. contortus + Dodonaea viscosa. The differences in runoff and sediment yield under different slope gradients and vegetation patterns were then compared. [Results] ① The rainfall-runoff distribution for the three vegetation patterns and bare land under slope gradients of 5° and 10° was dominated by surface runoff （80.94%—99.11%）. ② The three vegetation patterns significantly reduced surface runoff （73.13%—86.87%） and soil loss （69.29%—94.47%） by regulating runoff distribution across different soil layers， while correspondingly increasing interflow at depths of 50 cm and 100 cm （107.14%—980.00% and 47.17%—225.00%， respectively）. ③ At slope gradients of 5° and 10°， compared with bare land， H. contortus + P. emblica showed the greatest increase in interflow at 100 cm depth （225.00% and 181.13%， respectively） and effectively reduced soil loss （70.06% and 92.27%， respectively）. This pattern simultaneously demonstrated the functions of soil stabilization and water retention. ④ Among all rainfall characteristics， rainfall amount was most closely related to surface runoff， with a correlation coefficient of r = 0.665 （p < 0.05）. Specifically， rainstorms significantly increased surface runoff， causing the annual average surface runoff on 5° and 10° slopes to increase by 339.45% and 148.30%， respectively， compared with relatively heavy rain. [Conclusion] Soil erosion in dry-hot valleys is mainly affected by the combined effects of rainfall amount and surface runoff. The three vegetation patterns at the slope gradients of 5° and 10°achieve the goal of soil stabilization and water retention by regulating runoff distribution across different soil layers. Among them， H. contortus + P. emblica not only effectively reduce surface runoff but also effectively direct rainfall into deeper soil layers and reduce the sediment content in runoff. It is identified as the dominant vegetation pattern for regional soil and water conservation.

Abstract:[Objective] The species composition characteristics of the typical urban-suburban transition zone in Chengdu ring ecological zone were analyzed， in order to reveal the differences in plant diversity among different community types， management models and functional forest lands， and provide a scientific basis for the evaluation of the effectiveness of land consolidation and ecological restoration projects as well as the optimization of vegetation management. [Methods] Quadrats were established using a stratified random sampling method， and the Shannon-Wiener diversity index， Simpson dominance index， species richness index， and Pielou evenness index were used as measurement indicators to evaluate diversity. [Results] ①The urban-suburban transition zone exhibited rich plant diversity， with a total of 231 plant species belonging to 177 genera and 92 families recorded. Among them， native species accounted for 41.1%， domestically introduced species for 33.3%， and exotic species for 25.5%. In addition， the survey found 31 alien invasive plant species， predominantly herbaceous， accounting for 80.6%. ②The phytogeographic composition of seed plant genera was relatively complex， with pantropical distribution （29.4%） and north temperate distribution （18.6%） being dominant. ③The species diversity of the tree layer in mixed forests was significantly higher than that in deciduous broad-leaved forests （p<0.05）. The tree layer diversity was significantly lower in park-managed forests compared to non-park-managed forests （p<0.05）， and the species richness of the tree layer in landscape forests was significantly lower than that in non-landscape forests （p<0.05）. [Conclusion] The urban-suburban transition zone maintains a relatively high level of plant diversity， but requires heightened vigilance against the risk of invasion by alien species. It is recommended to strengthen dynamic monitoring and prioritize the selection of native evergreen broad-leaved tree species in ecological restoration.

Abstract:[Objective] The application benefits of different restoration and management measures in degraded grasslands were comprehensively evaluated， and the technical and application conditions for the management of natural degraded grasslands in the Bashang area of northern Hebei Province were analyzed， in order to provide technical and application experience for the ecological management of grasslands in the Bashang area， and to support the coordinated development of the ecological environment and rural revitalization. [Methods] From 2022 to 2024， experimental plots were established in Xinhua village in Baituyao Township and Lvyuan Village in Jiuliancheng Town， Guyuan County， with five natural grasslands located in Weichang， Fengning， Zhangbei， Kangbao， and Shangyi counties as control plots. Several intervention measures were implemented， including enclosure + root cutting， enclosure + fertilization， enclosure + grass planting， and enclosure only. Indicators such as community characteristics， surface characteristics， grass yield， and palatability of each plot were systematically investigated and analyzed. [Results] ① Within two years， the quality of degraded grasslands was significantly improved by enclosure + grass planting measures， with greater effectiveness observed in degraded typical grasslands compared to degraded meadow grasslands. The annual dry weight of grass yield increased by 54.25% and 48.18% in the degraded typical grasslands and degraded meadow grasslands under this treatment， respectively， while the annual dry weight of palatable forage grass increased by 2.10% and 1.20%， respectively. ② Enclosure + fertilization measures effectively increased vegetation coverage and reduced the proportion of bare ground， with vegetation coverage increasing by 1.20% and 1.60% annually， and bare ground decreasing by 0.60% and 0.80% annually in degraded typical grasslands and degraded meadow grasslands under this treatment. ③ Enclosure + root cutting measures could improve the plant community diversity to some extent， but the effectiveness varied by location. ④ Enclosure only was the least effective among the four measures， but still performed better than the control plots. [Conclusion] Compared with natural restoration， human intervention can significantly improve the plant community characteristics and productivity in the short term， but the overall impact on community species diversity is not significant. For the slightly degraded typical grasslands in the Bashang area of northern Hebei with production demands， the recommended order of restoration measures is enclosure + grass planting， enclosure + fertilization， and enclosure + root cutting. For grasslands without production demands， the measure of enclosure only is recommended. For degraded meadow grasslands with tourism value， the enclosure + fertilization measure is recommended to improve the community characteristics and enhance the landscape aesthetics.

Abstract:[Objective] The influencing mechanisms of synergistic improvement by biochar and potassium polyacrylate on the water characteristics of coal gangue in alpine mining areas were investigated， in order to enhance its water-holding and moisture conservation capacity and inhibit water loss via evaporation. [Methods] A laboratory soil column simulation experiment was conducted with different mass fractions of biochar （1.1%， 4.3%） and potassium polyacrylate （0.12%， 0.22%， 0.32%） in combined application （six treatments in total）， along with a control （CK）. The one-dimensional constant-head vertical infiltration method， continuous weighing method， and cutting-ring method were employed to determine the infiltration characteristics， evaporation process， and key water-holding parameters （saturated water content， capillary water-holding capacity， and field capacity） of the coal gangue matrix. [Results] The saturated water content of all treatments increased by 7.88% to 33.35% compared with CK. The addition of potassium polyacrylate significantly inhibited the transport distance of the wetting front， initial infiltration rate， average infiltration rate， and cumulative infiltration volume （p<0.01）. The multi-level pore adsorption of biochar， combined with the swelling and resistance-enhancing effect of potassium polyacrylate， jointly formed a ‘slow infiltration-strong water retention’ mode. This mode effectively inhibited rapid water infiltration and enhanced the capture and storage efficiency of water （e.g.， freeze-thaw water） in the root zone. The Kostiakov model could accurately characterize the infiltration patterns of the amended matrix （R²>0.916， RMSE<0.159）. Treatments with high amendment rates （e.g.， B₄P₃） showed significant evaporation inhibition effectiveness， achieving a maximum reduction of 19.88% in cumulative evaporation loss rate compared to CK， while maintaining higher residual water content. Under a bulk density of 1.41 g/cm³， considering water-holding characteristics， infiltration characteristics， and evaporation inhibition performance， the optimal amendment ratio of the coal gangue matrix was achieved in the B₄P₃treatment group， with a biochar mass fraction of 4.3% and a potassium polyacrylate mass fraction of 0.32%. [Conclusion] The B₄P₃ treatment significantly enhances the water-holding capacity and evaporation inhibition ability of coal gangue in alpine mining areas. The Kostiakov model demonstrates the best fit for the water infiltration process across all treatment groups.

Abstract:[Objective] The effects of rainfall characteristics and land use types on slope runoff and sediment yield in a typical small watershed of the Jialing River were investigated， in order to provide technical support and a theoretical basis for soil and water conservation and erosion control in this region. [Methods] The Lizikou small watershed in Nanbu County within the Jialing River Basin was selected as the study area. Based on five consecutive years of observational data from 2019 to 2023， including rainfall， runoff depth， and soil loss， K-means clustering method was used to classify rainfall characteristics， enabling analysis of erosive rainfall characteristics and types. Pearson correlation analysis was applied to evaluate the strength of linear correlation between rainfall characteristics and runoff and sediment yield. Multiple linear regression analysis was used to construct predictive models for runoff depth and soil loss based on rainfall characteristics. Additionally， the geodetector method was employed to explore the explanatory power of single factors and their interactions on runoff and sediment yield， so as to reveal the effect ive patterns of rainfall characteristics on runoff and sediment yield under different land use types. [Results] ① Erosive rainfall in the small watershed was classified into three types： Type I （small rainfall amount， short duration， low intensity）， Type Ⅱ （moderate rainfall amount， long duration， moderate intensity）， and Type Ⅲ （large rainfall amount， medium duration， high intensity）. Compared with Types I and Ⅱ， Type Ⅲ rainfall occurred less frequently but exhibited higher erosivity. For the same land use type， Type Ⅲ rainfall resulted in significantly greater slope runoff depth and soil loss. ② Significant differences in runoff and sediment yield were observed among plots with different land use types. Runoff depth and soil loss decreased in the order： bare land > slope cropland > arbor forest land. ③ All rainfall characteristic indicators were positively correlated with slope runoff depth and soil loss under different land use types. Among them， rainfall amount and rainfall erosivity had more pronounced effects. ④ Within the small watershed， rainfall amount had the greatest single-factor explanatory power for slope runoff and sediment yield， followed by I₃₀ （maximum 30-minute rainfall intensity）. After interaction-factor detection， most interactions were characterized by double-factor enhancement or nonlinear enhancement. [Conclusion] In the low mountainous and hilly regions of northeastern Sichuan， rainfall amount， I₃₀， and rainfall erosivity are the most critical factors influencing slope runoff and sediment yield. Slope cropland is the primary cause of soil erosion in this region， while arbor forest land can reduce runoff by up to 88% and sediment yield by up to 99% compared to bare land through multiple hydrological regulation mechanisms. Therefore， returning cropland to forests and grasslands is an effective measure to reduce soil erosion.

Abstract:[Objective] The coupling relationship between the morphological characteristics of Nitraria tangutorum nebkhas and their windbreak efficiency was investigated in order to reveal the effects of different evolutionary stages on nebkhas morphology and airflow fields， and to clarify the mechanisms by which shrub structure affects windbreak and sand-stabilization efficiency， furthermore to provide a theoretical basis and data support for the ecological restoration of the desert-oasis ecotone. [Methods] This study focused on N. tangutorum nebkhas in the desert-oasis ecotone of the Yabulai Mountain aeolian pass. Field measurements were used to determine the morphology of the nebkhas， and numerical simulations were conducted to analyze wind speed distributions in the vertical and horizontal planes under three evolutionary stages （development， stabilization， and degradation） and three vegetation cover levels （20%， 50%， and 80%）. [Results] ① The morphology of the N. tangutorum nebkhas was primarily tadpole-like elliptical. All morphological parameters showed positive correlations. The correlation coefficients increased as the nebkhas evolved and vegetation cover increased. All morphological parameters were the smallest in the development stage. ② For nebkhas at different evolutionary stages， wind speed decreased significantly within the horizontal distance range of x=1—5 L （L represents the shrub canopy major axis） and the vertical height range of z=0—0.8 H （H represents the shrub height ）， forming a deceleration zone on the leeward slope with high windbreak efficiency （40%—95%）. Among all evolutionary stages， the stabilization stage exhibited the optimal windbreak performance （with windbreak efficiency of 50%—95%）. ③ Under the three vegetation cover conditions， the windbreak efficiency reached the highest level of up to 95% when vegetation cover reached 80%. [Conclusion] The Yabulai Mountain Aeolian Pass is a key area for wind erosion control. Wind erosion can be mitigated by optimizing the morphological structure of the nebkhas and increasing vegetation cover.

Abstract:[Objective] The effects of different amendment measures on soil water and salt content， organic matter， nutrients， and microbial communities in saline-alkali soil of the Qingtongxia irrigation area in Ningxia Hui Autonomous Region were analyzed， in order to provide scientific support for improving saline-alkali land in this area， thereby further to promote food security， improve land resource use efficiency， and facilitate sustainable agricultural development. [Methods] A field experiment on saline-alkali soil improvement was conducted in the Qingtongxia irrigation area， with nine treatments established. The main treatment types included the addition of organic and inorganic materials， microbial inoculants， and different tillage practices. [Results] ① Except for T₉ （where maize roots were 70 cm from the drip irrigation belt）， soil water content in the 0—40 cm soil layer significantly increased under the other treatments. Among these， T₅ （film mulching） showed the greatest increase， with its surface soil water content increasing by 35.59% compared with the control T₁ （no amendment application， no mulching， and no deep ploughing）. The pH value and total salt content in the 0—40 cm soil layer generally decreased across all treatments. The greatest reductions were observed in T₃ （phosphogypsum + natural humus + nitrohumic acid） and T₅， with pH value decreasing by 0.27—0.37 and salt content decreasing by 27.36%—41.82%. ② In the 0—20 cm soil layer， all treatments except T₉ significantly increased soil organic matter and nutrients compared to the control. The increases in organic matter， alkali-hydrolyzed nitrogen， available phosphorus， and available potassium were 3.13%—20.66%， 3.50%—127.50%， 5.05%—115.06%， and 5.06%—105.86%， respectively. T₃ showed the most significant increase. ③ The richness and diversity of the soil microbial communities significantly increased. T₃ and T₅ treatments notably increased the relative abundances of dominant bacterial genera Microbulbifer and Pseudomonas， as well as the dominant fungal genus Mycena. In all treatments， bacterial functional genes were mainly associated with amino acid metabolism， carbohydrate metabolism， and energy metabolism. The major fungal types were saprotrophic， symbiotic， and pathogenic. Soil under T₅ and T₇ （deep plowing + film mulching） had a higher abundance of beneficial symbiotic fungi. [Conclusion] The combination of film mulching with organic and inorganic amendments can significantly reduce soil pH value and total salt content， increase organic matter and nutrient content， and enhance microbial richness and diversity， demonstrating significant effectiveness in improving saline-alkali soil in the Qingtongxia irrigation area.

Abstract:[Objective] The spatiotemporal patterns of rainfall-induced landslides in Chongqing City and their correlation with rainfall were analyzed， in order to provide a scientific basis for regional early warning and prediction of such landslides， with the goal of reducing losses caused by geological disasters. [Methods] Using rainfall-induced landslides during the 2024 flood season in Chongqing City as the research subject， statistical and geospatial analysis methods were applied to examine the geological environmental characteristics of landslides and their association with rainfall. I-D， E-D， and E-I rainfall threshold models were established， and their accuracy was compared using a confusion matrix. The predictive capability of the models was evaluated using landslide data from June 2025. [Results] ① Landslides in the study area primarily occurred in low-elevation areas （500—1 000 m）， on north-facing slopes， with gradients of 10°—30°， in soft rock formations， and within 800 m of folds and river systems. ② The occurrence of landslides was closely related to rainfall， exhibiting clear critical threshold effects， hysteresis， and nonlinear characteristics. ③ Among the various rainfall threshold models established， the I-D model demonstrated superior comprehensive predictive performance compared to others， making it more suitable for landslide early warning in the region. ④ The established I-D threshold model for Chongqing’s flood season landslides was region-and period-specific， with values higher than global and annual thresholds for Chongqing but lower than thresholds for southeastern China and national extreme events. It can serve as a key criterion for early warning during the flood season in this area. [Conclusion] The geological environment controls the spatial distribution pattern of landslides， while rainfall is the key triggering factor. The established I-D threshold model provides a critical basis for regional early warning. Achieving precise early warning in the future will require moving beyond single rainfall criteria and developing dynamic comprehensive models that integrate multiple factors.

Abstract:[Objective] The development characteristics of the debris flow in Nangang gully， Fangshan District， Beijing City were analyzed to reveal the differences in material source composition and disaster-causing mechanisms of rainstorm-induced debris flow in the southwest mountainous areas of Beijing City， in order to provide theoretical support for debris flow prevention and control in the local area fand similar regions. [Methods] Taking the debris flow disaster that occurred in Nangang gully after the ‘23·7’ rainstorm in Beijing as the research object， topographic data were acquired using unmanned aerial vehicle （UAV）， and terrain， material source， and water source conditions were analyzed in combination with field investigations. The FLO-2D model was used to simulate the dynamic process of the debris flow， with a focus on quantifying movement parameters under the dendritic gully-high and steep slope topography. The results were then validated against field investigation data. [Results] Nangang gully featured large topographic relief and deeply incised valleys， with abundant and diverse material sources （including landslide deposits， slope erosion deposits， and channel deposits）. Atmospheric precipitation served as the main water source， and rainstorms were the primary triggering factor for debris flow. The FLO-2D simulations showed that the maximum sliding velocity of the debris flow was 6.75 m/s， and the maximum accumulation depth was 14.6 m. The error rate between the simulation and field investigation results was 3.995%， which was within a reasonable range. A comprehensive analysis confirmed that the susceptibility index of debris flow in Nangang gully was 2—3， classifying it as a debris flow-prone gully. [Conclusion] The Nangang gully debris flow is a typical rainstorm-induced gully-type dilute debris flow， with its formation following the process of ‘rainfall infiltration—runoff concentration—channel bed scouring—material convergence’， and the gully is classified as a debris flow-prone area. The FLO-2D simulation has been verified to be reliable.

Abstract:[Objective] The research status， progress， and evolutionary trends of research frontiers and hotspots in the field of global soil and water loss monitoring technology from 1993 to 2023 were analyzed， and its development trends were outlined， in order to provide references for promoting innovation and advancement in soil and water loss monitoring technology. [Methods] A total of 943 publications in the field of soil and water loss monitoring technology from 1993 to 2023 were selected from the Web of Science Core Collection and the China National Knowledge Infrastructure （CNKI） databases. CiteSpace bibliometric software was employed to conduct visual analysis of publication trends， country and institutional distribution， author collaboration networks， keyword clustering， and keyword bursts. [Results] ① The global publication volume exhibits continuous growth， and research had entered a stage of rapid development after 2010. China was the center of global publication volume， and both China and the United States exerted the greatest academic influence worldwide in this field. ② Institutions including the Chinese Academy of Sciences and Beijing Normal University had relatively broad research scopes and extensive collaboration networks. Scholars such as Liu Baoyuan and Poesen Jean were highly reputed authors with significant publication volume in this field. ③ Research hotspots in both databases were concentrated in the Loess Plateau and northeast China， two regions severely affected by soil and water loss. Gully erosion and slope erosion were the primary types of soil loss receiving significant attention. [Conclusion] Soil and water loss monitoring technology has transitioned from traditional to modern measurement. The integration of multiple technologies has become a key trend in this field， thereby enhancing monitoring effectiveness.

Abstract:[Objective] The environmental characteristics of wind and sand in Gansu Dunhuang Xihu National Nature Reserve were analyzed， in order to provide a basis for the scientific and effective implementation of wind and sand control and ecological protection in the reserve. [Methods] Taking this area as the research object， wind speed and direction data from the automatic weather station in the monitoring area in 2019， 2020， 2023， and 2024 were statistically processed through field observation. The wind conditions and wind-sand environment of the Dunhuang Xihu Reserve were analyzed and discussed. [Results] ① The four-year average sand-driving wind speed in the Dunhuang Xihu National Nature Reserve ranged from 6.28 m/s to 6.43 m/s. The annual maximum wind speed was approximately 14 m/s， and the annual average sand-driving wind frequency was 8.43%. Sand-driving winds were mostly concentrated in spring and summer， accounting for 73.29% of the whole year， with sand-driving wind frequencies ranging from 11% to 12% in these two seasons. The sand-driving wind directions in the reserve were mainly E and ENE. Among these， the single direction with the largest proportion was E， while that with the smallest proportion was SE. ② The annual average drift potential （DP） was 666.39 VU， classifying the area as a high wind-energy zone. Similar to sand-driving winds， DP was mainly concentrated in the E and ENE directions. The annual average resultant drift potential （RDP） was 141.09 VU， and the annual average directional variability index （RDP/DP） was 0.24， indicating low directional variability. The wind conditions were relatively complex， characterized as a compound or blunt bimodal pattern. ③ The seasonal differences in drift potential were significant， mainly concentrated in spring and summer， accounting for 80.8% of the whole year. The drift potential was highest in summer and lowest in winter. The directional variability of the drift potential for the four seasons was 0.29， 0.43， 0.34， and 0.39， respectively， indicating medium to low variability. The wind conditions in all four seasons were relatively complex. [Conclusion] The reserve is a high wind-energy zone， with prevailing east-west winds throughout the year. Sand-driving winds and drift potential are primarily concentrated in spring and summer. The annual and seasonal directional variability of the drift potential is medium to low， and the wind conditions are relatively complex. It is necessary to carry out wind prevention and sand control as well as ecological restoration work in a way that suits local conditions.

Abstract:[Objective] An image segmentation method for large wood based on the segment anything model （SAM） was introduced， in order to provide theoretical support for its application in investigating and assessing large wood disasters. [Methods] The Zebagou area in Gongjue County， Chamdo City， Xizang Autonomous Region was selected as the study area， based on SAM， a segmentation method for large wood images—large wood SAM （LWSAM）-was developed by introducing a lightweight adapter， simplifying the mask decoder， designing a multi-task loss function， and adding an auxiliary classifier. During training， the parameters of the original image encoder and the prompt encoder were frozen to improve large wood segmentation performance at a low training cost. The model was trained and tested on two datasets， LW_CAM_dataset and LW_UAV_dataset， and compared with current state-of-the-art image segmentation models. [Results] ① The proposed multi-task loss function could optimize segmentation quality from different perspectives， effectively address the issues of sparse foreground and class imbalance in large wood recognition， and enhance the model’s adaptability to various large wood morphologies. ② Compared with the SAM method， under point prompt conditions， LWSAM achieved improvements of 15.9%， 15.9%， and 10.0% in MDice， MIoU， and F1 score， respectively， on the LW_CAM_dataset， and improvements of 21.6%， 29.6%， and 16.7% on the LW_UAV_dataset， respectively. ③ The performance of large wood segmentation was influenced by dataset quality， with models trained on higher-quality datasets achieving better segmentation results. [Conclusion] Using LWSAM for large wood image segmentation is feasible， and it demonstrates high accuracy and strong robustness in practical applications， enabling accurate segmentation of large wood images. This approach can be applied to large wood disaster investigations in small watersheds.

Abstract:[Objective] A model will be established to address the issues existing in current soil moisture prediction models， such as insufficient spatial feature mining， limitations in temporal dynamic modeling， and weak adaptability to data distribution differences in the collaborative optimization of complex spatiotemporal dynamic representation and cross-scenario sample generalization. This will provide a scientific decision-making tool for dynamic early warning of drought and flood disasters， precision allocation of irrigation resources， and improved agricultural disaster resistance. [Methods] To address these issues， an attention-guided spatiotemporal feature dynamic fusion network （AGSMP-Net） was proposed. The model integrated a long short term spatiotemporal prediction network with a feature-time-space attention mechanism module， enabling focused processing of time-series information and the capture of spatial distribution variations. It identified the long-term variation trends of soil moisture and optimized the utilization of information across spatiotemporal dimensions. [Results] Experiments validated the feasibility of the AGSMP-Net model in predicting soil moisture using meteorological factors （precipitation and soil temperature）. In the soil moisture prediction task for Henan Province from 2015 to 2024， compared to ConvLSTM， AGSMP-Net model improved the accuracy （R²） from 0.758 to 0.806 and reduced the root mean square error （RMSE） from 0.069 to 0.057. Precipitation has a significant effect on the prediction accuracy of soil moisture model. [Conclusion] The proposed model dynamically allocates feature weights through the spatiotemporal attention mechanism， which can effectively capture both the abrupt responses and steady-state trends in soil moisture variations， thereby improving the accuracy of soil moisture prediction.

Abstract:[Objective] The trend of soil erosion in Qinghai Province from 2004 to 2023 and its driving factors were systematically analyzed， in order to provide a scientific basis for soil and water conservation in alpine regions. [Methods] By analyzing the soil erosion situation and conservation efforts in Qinghai Province from 2004 to 2023， and using correlation analysis， this study identified the changing trend of soil erosion area in Qinghai Province and its relationship with factors such as investment in soil and water conservation， supervision and management efforts， and the area treated by various control measures. [Results] The area of soil erosion in Qinghai Province decreased from 2.04×10⁵ km² in 2004 to 1.59×10⁵ km² in 2023. The proportion of moderately eroded area decreased from 22.5% to 11.4%， and the proportion of severely and above eroded area of the total eroded area decreased from 37.2% to 17.0%. Increasing investment in soil and water conservation funds and strengthening supervision and management were the main driving forces for the reduction of soil erosion area. [Conclusion] Overall， soil erosion control in Qinghai Province has shown a significant improving trend， with the soil erosion area decreasing year by year. However， there are still problems that need to be addressed. Soil and water conservation efforts have gradually shifted from generalized and extensive management across the entire region to targeted management in key areas. Future work will focus on regions affected by wind erosion and mild erosion. Additionally， the achievements of the control efforts will be consolidated， and the progression from mild erosion to severe erosion will be prevented. The establishment of a value realization mechanism of soil and water conservation ecological products should be accelerated， and the sustainable development of soil erosion control efforts should be established.

Abstract:[Objective] A landslide susceptibility evaluation framework that integrates the characteristics of Karst landforms was constructed， in order to reveal the dominant factors and their interaction mechanisms， and provide a theoretical basis for the precise control of landslide risks in Karst landform areas. [Methods] The study area was Guilin City， Guangxi Zhuang Autonomous Region. We innovatively integrated Karst characteristics to construct a geospatial database containing nine key factors. Five machine learning models-logistic regression （LR）， support vector machine （SVM）， random forest （RF）， gradient boosting machine （GBM）， and XGBoost-were used for landslide susceptibility modeling. Hyperparameters were optimized via a grid search， and the model performance was evaluated using accuracy and area under the receiver operating characteristic curve （AUC） metrics. The shapley additive explanations （SHAP） algorithm was applied to quantify the contributions of the various factors and their interactive effects. [Results] The ensemble models RF and XGBoost exhibited the best performance， achieving the highest accuracy （0.85 and 0.84， respectively） and AUC values （0.93 and 0.92， respectively）. All models showed a trend of a sharp increase in landslide density with decreasing land area. The RF model yielded the highest landslide density in the extremely high-risk zones （0.164 events/km²）. The SHAP analysis indicated that the groundwater content was the most influential Karst factor in most models. It also revealed the interactive effects of the normalized difference vegetation index， distance to rivers， and soil type. The ensemble models exhibited high consistency in terms of feature interpretation. [Conclusion] Integrating ensemble models such as RF with the SHAP framework significantly improves the accuracy and interpretability of landslide susceptibility mapping in Karst regions. The results of this study confirm the synergistic disaster-forming mechanism between the groundwater content and soil type.

Abstract:[Objective] A nature-based solutions （NbS） synergistic benefit assessment framework applicable to the Dongting Lake ecological economic zone was constructed，in order to seek differentiated NbS implementation schemes to enhance regional hydrological rhythm adaptation index，and to provide operable optimization pathways for the hydrological dynamic management in ecologically sensitive areas. [Methods] Taking the Dongting Lake ecological economic zone as the study area， this study constructed an NbS synergistic benefit assessment framework integrating the hydrological rhythm adaptation index （HRAI） and the InVEST model， comprehensively analyzing the effects of NbS on flood regulation， ecological water supplementation， and flow stability. [Results] ① The regional annual average HRAI increased from 0.317 in 2022 to 0.327 in 2024， indicating that NbS measures effectively improved flood regulation and eco-hydrological stability. ② Hilly wetlands and forests could synergistically enhance rhythm adaptation index and the supply capacity of ecosystem services such as water yield and soil conservation， while improvements in lakeside plains and built-up areas were limited. [Conclusion] It is recommended to prioritize the implementation of ecological ditches and vegetation restoration projects in hilly wetlands， promote the construction of ecological slow-release and time-based regulation systems in plain areas， and promote sponge measures such as rain gardens and permeable pavements in built-up areas. This will increase available water content， extend ecological water supplementation days， and optimize flood pulse thresholds， thereby achieving a steady improvement in the HRAI.

Abstract:[Objective] This study aims to establish a technical pathway of ‘factor selection-model evaluation-mechanism analysis’ to investigate evaluation models with high predictive accuracy for landslide susceptibility， reveal the key driving factors of landslide disasters， and explore the interaction mechanisms among landslide influencing factors under complex geological conditions. It can provide scientific support for disaster risk management and the formulation of ecological protection strategies in the Jiuzhaigou scenic area and similar post-seismic regions with highly concealed landslides. [Methods] The Jiuzhaigou scenic area was selected as the study area. Landslide susceptibility was evaluated using both traditional methods-analytic hierarchy process （AHP）， information value （IV）， and certainty factor （CF） and machine learning models （XGBoost， LightGBM， and CatBoost）. A systematic evaluation indicator system was constructed based on correlation analysis and collinearity tests. The shapley additive explanations（SHAP） explainable algorithm and the optimal parameter-based geodetector model （OPGD） were used to identify key controlling factors and investigate their interaction mechanisms. [Results] Among the landslide susceptibility evaluation models， the machine learning models overall outperformed the traditional methods， with the CatBoost model achieving the highest predictive accuracy （AUC=0.927）. High-susceptibility zones were concentrated in Panda Lake， Arrow Bamboo Lake， northwestern Danzugou， southwestern Grass Lake， and southeastern Long Lake. Both SHAP and OPGD identified distance to water systems， normalized difference vegetation index （NDVI）， slope aspect， and multi-year average annual rainfall as the primary controlling factors. OPGD interaction detection revealed that the interaction between distance to water systems and distance to faults was the strongest （q=0.33）， and the relationship between multi-year average annual rainfall and NDVI showed a nonlinear enhancement （q=0.16）. [Conclusion] There are multiple potential zones of high landslide susceptibility within the Jiuzhaigou scenic area. Based on high-accuracy evaluation models， the SHAP algorithm effectively identifies key driving factors. Moreover， the synergistic effects of multiple factors are the key mechanisms for landslide development in this region.

Abstract:[Objective] The spatiotemporal distribution characteristics and variation trends of rainfall erosivity in Yulin City of Shaanxi Province were explored ， in order to provide theoretical guidance for studying the regional soil erosion patterns and formulating soil and water conservation measures. [Methods] Based on daily rainfall data collected at 18 meteorological stations in and around Yulin City from 1991 to 2023， the rainfall erosivity values at each station were calculated using a daily rainfall erosivity model. The spatiotemporal distribution characteristics and variation trends of rainfall erosivity over the past 33 years in Yulin City were then explored and analyzed using statistical methods. [Results] The annual average rainfall erosivity in Yulin City was 952.88 MJ·mm/（hm²·h·a）， and the annual average erosive rainfall was 270.87 mm. The rainfall erosivity and erosive rainfall at each station in Yulin City were unevenly distributed throughout the year， mainly concentrated in summer and autumn. The spatial distribution patterns of rainfall erosivity and erosive rainfall were generally consistent， both showing an overall increasing trend from northwest to southeast. In the future， except for Wubao station which would continue its historical trend， the rainfall erosivity at all other stations was projected to show trends opposite to the past， with rainfall erosivity and erosive rainfall expected to gradually decrease. [Conclusion] The annual rainfall erosivity in Yulin City shows a fluctuating upward trend， with significant interannual fluctuations observed at various stations. The future trend of rainfall erosivity in this region is projected to decrease. However， significant uncertainties remain regarding its variation trend. Therefore， it is necessary to strengthen soil and water conservation management and soil erosion prevention， particularly at stations where rainfall erosivity shows an increasing trend.

Abstract:[Objective] The relationship between the carbon balance capacity of black soil areas and urbanization were analyzed in order to provide a empirical evidence for promoting the rational land use， enhancing carbon sequestration， reducing black soil areas， and achieving sustainable development and management of regional land. [Methods] Panel data from 22 prefecture-level cities covering black soil from 2007 to 2022 were analyzed using the Granger causality tests， land-use carbon emission intensity measurement models， and kernel density estimation methods. [Results] ① Regarding the spatial distribution of black land carbon emissions， a trend of higher emissions on ‘both sides and lower in the middle’ was observed， with a northward increase over time. ② The impact of urbanization level on carbon balance capacity can be categorized into four types： growth， feedback， protection， and neutrality. ③ In cities with better economic growth， there was a causal relationship between the black soil areas carbon balance capacity and population urbanization， economic urbanization， and ecological urbanization. In industrialized cities， a causal link exists between black soil areas carbon balance capacity and spatial urbanization， whereas in other cities， causal relationships exist between black soil areas carbon balance capacity and comprehensive urbanization indicators. [Conclusion] Based on these insights， it is recommended that the spatial pattern of urbanization be optimized according to specific influence types in different regions to balance regional ecology and urban development in black soil areas. Such tailored strategies will facilitate black soil areas conservation and support the achievement of the carbon neutrality goals.

Abstract:[Objective] The spatiotemporal evolution， driving mechanisms， and carbon economic value of terrestrial ecosystem carbon storage and habitat quality in Hubei Province were analyzed in order to provide a scientific basis for regional ecological protection and green low-carbon development. [Methods] Based on land use data from 2010 to 2023， this study utilized the PLUS model to simulate land use patterns under natural development， economic development， and comprehensive development scenarios in 2030. The InVEST model was employed to evaluate the spatiotemporal variations of carbon storage and habitat quality. The geodetector was employed to analyze the driving factors， and the present value method was used to estimate the economic value of carbon storage. [Results] ① Land use exhibited a pattern of ‘initial expansion followed by optimization’. After 2020， ecological policies effectively curbed the expansion of construction land and promoted the restoration of forestland and water bodies. ② Carbon storage showed a trend of ‘initial decline followed by rise’， with a spatial distribution of ‘high in the west and low in the east’. Slope， elevation， and NDVI were the primary drivers of the spatial differentiation， and the influence of socioeconomic factors strengthened gradually. ③ Habitat quality declined overall but showed local improvements. Low-quality habitats expanded. The western mountainous areas of Hubei Province maintained high quality， while the central plains were significantly affected by human activities. ④ Under the comprehensive development scenario， the economic value of carbon storage reached the highest value （2.69×10¹³ yuan） through ecological restoration and land use regulation. [Conclusion] Natural and anthropogenic factors jointly drive the evolution of carbon storage and habitat quality. Under the comprehensive development scenario， a win-win outcome of ‘carbon sink enhancement’ and ‘quality improvement’ can be achieved， thereby providing scientific support for ecological planning in Hubei Province.

Abstract:[Objective] The coupling coordination level and spatio-temporal differentiation between the resilience of resource-based cities and carbon emissions in the Yellow River basin were analyzed to provide a scientific basis for promoting high-quality development across the entire river basin. [Methods] Based on evaluation index system of urban resilience， the coupling coordination degree， spatio-temporal evolution， and spatial agglomeration between urban resilience and carbon emission were analyzed by the coupling coordination model and the spatial autocorrelation model. [Results] ①Urban resilience and carbon emissions of resource-based cities in the Yellow River basin showed increasing and decreasing trends， respectively. The change in urban resilience occurred faster than that in carbon emissions， and there were differences among different regions. ②The level of coupling coordination in resource-based cities was characterized by a ‘small increase followed by a rapid rise’， with the growth rate in the middle reaches being faster than that upstream and downstream. ③The level of coupling coordination improved significantly； however， there were substantial differences among the different regions. ④Some resource-based cities were gradually distributed in ‘high-low’ areas and characterized by a ‘block-like’ distribution. [Conclusion] Resource cities in the Yellow River basin need to integrate regional resources， factor advantages， and formulate personalized improvement paths to achieve the collaborative goal of ‘carbon sequestration and sink enhancement upstream， carbon reduction and efficiency improvement in the middle reaches， and low-carbon intensification downstream’， which will contribute to promoting coordination between resilience improvement and carbon reduction in basin.

Abstract:[Objective] The coupling coordination relationship between agricultural new quality productive forces and green technology innovation were analyzed， in order to provide scientific basis for ensuring food security and ecological security， and for promoting the transition of agriculture from ‘quantity increase’ to ‘dual improvement in quality and efficiency’. [Methods] Based on panel data from 30 provinces in China from 2012 to 2022， the spatiotemporal distribution characteristics were analyzed using a coupling coordination model and Moran’s index， and its carbon emission reduction effects were examined using the fixed effects model and spatial Durbin model. [Results] Temporally， the coupling coordination development of the 30 provinces in China and across the four major regions （eastern， central， western， and northeastern China） showed an overall upward trend but a slight decline in the past two years. Spatially， the coupling coordination development demonstrated a certain degree of spatial clustering. The number of provinces in the ‘high-high’ clustering zone increased slightly in the eastern region， while the improvement in the ‘low-low’ clustering zone in the western region remained insignificant. In terms of carbon emission reduction， empirical tests using measurement models confirmed that the coupling coordination development of agricultural new quality productive forces and green technology innovation could promote agricultural carbon emission reduction and had a significant spatial spillover effect. [Conclusion] It is recommended to develop agricultural new quality productive forces and green technologies tailored to local conditions， reduce inter-regional disparities， establish cross-regional coordination mechanisms to promote carbon emission reduction， and facilitate inter-regional exchange and collaboration.

Abstract:[Objective] The effects of different retrofitting measures on the growth and carbon stock of Cunninghamia lanceolata plantations were evaluated， in order to provide a theoretical basis for developing optimal forest retrofitting strategies for the region. [Methods] The research was conducted within C. lanceolata plantations at Taizishan Shilong Forestry Retrofitting Bureau， Hubei Province. Guided by near-natural forest retrofitting principles， three treatments were applied： thinning with replanting （T₁， 50% thinning intensity with interplanting of Schima superba）， thinning only （T₂， 50% thinning intensity）， and an unimproved control （CK）. Diameter at breast height （DBH）， tree height， individual tree volume， stand volume， and DBH class distribution were measured. Carbon stocks within the tree layer， shrub layer， herb layer， and total vegetation layer were also quantified and compared among treatments. [Results] After three years， DBH growth and individual tree volume increment were significantly higher in T₁ compared to CK （p<0.05）. Tree height growth showed no significant differences among treatments （p>0.05）. The T₁ and T₂ treatments significantly increased the proportion of trees in medium and large DBH classes （≥20 cm）， while CK still dominated with small-diameter trees. Specifically， in T₁， the proportion of trees with DBH increments of 2—4 cm over three years was 28.3%， representing a 23.7% increase over CK. Overall， the thinning measures， particularly T₁， shifted the stand DBH distribution towards larger diameter classes. Carbon stock allocation within the vegetation layer followed the order： tree layer > shrub layer > herb layer across all treatments. The three-year growth in total vegetation layer carbon stock and tree layer carbon stock within T₁ did not differ significantly from CK （p>0.05）. Although the total vegetation carbon stock in T₁ remained lower than CK （primarily due to tree removal during thinning）， its higher subsequent growth rate indicated greater long-term carbon sequestration potential. Carbon stock growth within the shrub and herb layers showed no significant differences among treatments （p>0.05）. However， T₁ significantly increased the mean annual increment （MAI） of carbon stock in the shrub layer， while T₂ significantly increased the MAI in the herb layer. [Conclusion] Thinning combined with replanting C. lanceolata demonstrated significant advantages over thinning alone in promoting the growth of dominant C. lanceolata trees， optimizing stand structure， and enhancing the carbon stock growth rate within the key carbon pool （tree layer）. Consequently， T₁ represents a more suitable approach for promoting near-natural retrofitting in similar Chinese fir plantations and enhancing forest carbon sink functionality in the Taizi Mountain region of Hubei Province.

Abstract:[Objective] A precise mesurement method for check dam carbon sinks at the small watershed scale was established and the vertical distribution patterns of soil organic carbon （SOC） in the dam land were elucidated to provide a scientific basis for carbon sink trading of check dams. [Methods] Taking the check dam system at Gaoxigou small watershed of Mizhi County， Shanxi Province as a case study， based on the 1：10 000 topographic map of 1978 and aerial survey data in 2024， the sediment deposition volume was calculated by fitting the dam height-area curve. A mechanical drilling rig was employed to conduct full-depth stratified sampling， obtaining 312 soil samples from five check dams in the study area for SOC content measurement. Combined with the sediment deposition data， the total carbon sink of Gaoxigou check dam system （including both erosion and emission reduction as well as vegetation and carbon sink increase） was calculated. [Results] The total sediment deposition of Gaoxigou check dam system was 1.39 × 10⁶ m³， with a carbon storage of 20 459.37 t （using carbon dioxide equivalent as the measurement unit）. The erosion and emission reduction was 7 160.78 t， and the vegetation and carbon sink increase was 489.75 t， resulting in a total carbon sink of 7 650.53 t. The vertical distribution of SOC in the dam land of Gaoxigou check dams exhibited a significant surface aggregation effect. However， an anomalous peak in SOC content was observed in the middle layer， potentially indicating the shaping effect of regional flood deposition history on the SOC vertical distribution patterns in the dam land. [Conclusion] The integration of aerial survey with early large-scale topographic maps can be directly applied to calculate the sediment deposition of check dam systems in small watersheds， providing important reference value for monitoring the carbon sink of check dams on the Loess Plateau.

Abstract:[Objective] The spatiotemporal evolution patterns and driving mechanisms of natural capital utilization in countries participating in the Silk Road Initiative were analyzed in order to provide scientific support for regional sustainable development. [Methods] Based on an improved three-dimensional ecological footprint model， this research integrates spatial autocorrelation analysis and Tobit regression to construct a multidimensional evaluation framework of ‘spatiotemporal evolution-spatial correlation-driving mechanisms’. [Results] ① The per capita ecological footprint breadth showed a gradient differentiation pattern， with Singapore consistently having the lowest， while Mongolia and Latvia having the highest values. ② The ecological footprint depth exhibited significant polarization， with Singapore maintaining an extremely high level over the long term， while countries such as Russia at the baseline value. ③ The three-dimensional ecological footprint displayed a differential pattern of ‘high in developed countries and low in developing countries’. However， owing to energy efficiency optimization， China’s growth rate had slowed， providing a transformation paradigm for developing countries. ④ The spatial correlation demonstrated dynamic strengthening characteristics， with Moran’s I index increasing from 0.142 to 0.298. Regions such as Russia showed ‘high-high aggregation’， while South Asian countries were primarily characterized by ‘low-low aggregation’. China’s spatial correlation had shifted from ‘low-high’ to ‘insignificant’. ⑤ Urbanization rate， trade openness， renewable energy share， and ecological carrying capacity had considerable positive driving effects on the three-dimensional footprint， whereas net primary productivity and foreign direct investment exhibit inhibitory effects. [Conclusion] The utilization of natural capital in countries participating in the Belt and Road Initiative shows significant spatial heterogeneity and path dependence. Differentiated governance strategies， such as coordinating the ecological boundaries of urbanization， optimizing the allocation of ecological costs in trade， and overcoming technological lock-ins in renewable energy are required to promote the sustainable use of natural capital.

Abstract:[Objective] The spatiotemporal evolution characteristics of agro-ecological resilience and the main obstacle factors were investigated， in order to provide scientific references for the realization of food security and high-quality agricultural development. [Methods] Based on panel data from 60 prefecture-level cities in the Yellow River basin from 2008 to 2022， a three-dimensional agro-ecological resilience evaluation system of “resistance and driving， adaptation and reconstruction， innovation and development” was developed. The entropy weight method， Dagum Gini coefficient， exploratory spatial data analysis （ESDA）， and obstacle degree model were employed to quantify and analyze the agro-ecological resilience. [Results] The agro-ecological resilience of the main grain-producing areas in the Yellow River basin showed the following characteristics： ① Overall， a fluctuating upward temporal trend was observed， along with an uneven spatial distribution characterized by ‘higher in the east and lower in the west， stronger in the north and weaker in the south’. ② In terms of regional differences， the overall spatial variability was small， and inter-regional differences were the main source of total variation. ③ In terms of spatial clustering， significant clustering characteristics were observed， dominated by H-H and L-L clustering patterns， and the local spatial correlation patterns remained relatively stable. ④ Regarding obstacle factors， the capacity for adaptation and reconstruction was the main dimension constraining the improvement of agro-ecological resilience. Specifically， the level of agricultural technology investment and rural residential electricity consumption were the main obstacle factors. [Conclusion] The main grain-producing areas in the Yellow River basin can improve agro-ecological resilience by implementing region-specific agro-ecological development， strengthening regional ecological collaborative governance， and establishing a low-carbon agricultural development mechanism.

Abstract:[Objective] The spatiotemporal variations of soil water erosion in the eastern region of the agro-pastoral ecotone in northern China were investigated， and the effects of multi-factor interactions on water erosion dynamics were quantified first time， in order to provide decision-making support and methodological references for soil erosion control and ecological environment restoration in this region. [Methods] Based on the RUSLE model， an attribution analysis was conducted on the spatiotemporal differentiation characteristics of soil water erosion in the eastern region of the agro-pastoral ecotone in northern China from 2000 to 2023， and a quantitative analysis was performed on the main contributing factors to dynamic changes in soil water erosion. [Results] ① The multi-year average soil water erosion modulus in the eastern region of the agro-pastoral ecotone was 777.94 t/（km²·a）， with most areas dominated by very slight and slight erosion， accounting for 69.3% and 22.9% of the total water erosion area， respectively. ② From 2000 to 2023， the soil water erosion intensity in the study area showed a slight increasing trend， with an increase rate of 0.90 t/（km²·a）. Soil water erosion alleviated in the southeastern and northwestern parts of the region， while it intensified in the western part. ③ Areas prone to soil water erosion in the eastern region of the agro-pastoral ecotone were mainly distributed in Chifeng City in the central part， and Zhangjiakou City and Xilinhot in the southwestern part of the study area. ④ The main contributing factor to dynamic changes in soil water erosion in the eastern region of the agro-pastoral ecotone from 2000 to 2023 was the vegetation cover management factor， with an average contribution rate of 64.18%. The combined effects of three factors （vegetation cover management factor， soil and water conservation measure factor， and rainfall erosivity factor） accounted for 23.12%. The average contribution rates of soil and water conservation measure factor and the rainfall erosivity factor were 10.57% and 2.13%， respectively. There were strong interactions among parameters of the RUSLE model， and the combined effects of multiple factors contributed significantly to the dynamic changes in water erosion in the study area. [Conclusion] From 2000 to 2023， soil water erosion in the eastern region of the agro-pastoral ecotone in northern China was generally stable. During the study period， with the increase in vegetation cover and the effective implementation of soil and water conservation measures， the aggravating effect of increased rainfall erosivity on water erosion intensity was alleviated to a certain extent. However， the soil water erosion situation in this region remains relatively severe. Areas with low vegetation cover and those without soil and water conservation measures are the key focus areas for soil erosion control in this region.

Abstract:[Objective] The differentiated ecological compensation of cultivated land in Chinese provinces were analyzed， in order to provide a reference for promoting the realization of the ecological product value of cultivated land and ensuring the sustainable utilization of cultivated land resources. [Methods] An improved equivalent factor method was adopted to comprehensively assess the ecological product values of dryland， paddy field， and irrigated land in China and each province. Based on the average non-market ecological product value of national cultivated land， the inter-provincial horizontal ecological compensation standard for cultivated land is determined. Based on the non-market ecological product values of dryland， paddy field， and irrigated land in each province， the government payment capacity index was introduced to determine the intra-provincial vertical ecological compensation standards for dryland， paddy field， and irrigated land within the provinces. [Results] The ecological product values of dryland，paddy field，and irrigated land in China were 11 386.40，11 045.66，and 11 216.03 yuan/hm²，respectively.The inter-provincial horizontal ecological compensation standard for cultivated land was 7 492.08 yuan/hm²； The ecological compensation standards for dry land in 28 provincial regions ranged from 3 293.35 yuan/hm² （Guizhou） to 15 741.81 yuan/hm² （Jiangsu）. The ecological compensation standards for paddy fields in 25 provincial regions ranged from 2 911.51 yuan/hm²（Guizhou） to 19 557.56 yuan/hm²（Shanghai）.The ecological compensation standards for irrigated land in 20 provincial regions ranged from 3 126.82 yuan/hm² （Gansu） to 16 717.06 yuan/hm² （Beijing）. [Conclusion] Cultivated land holds significant ecological product value， and ecological compensation serves as an important means to realize this value. This study proposes a dual-level ecological compensation framework of “inter-provincial horizontal + intra-provincial vertical”， which considers both responsibility sharing for cultivated land ecological protection across provinces and differentiated measures for different types of cultivated land within provinces. The findings can provide a quantitative basis for the government to formulate differentiated ecological compensation policies for cultivated land.

Abstract:[Objective] The spatio-temporal pattern and driving factors of rural resilience in counties within the Yimeng Mountain region were anlyzed in order to provide scientific reference for formulating differentiated resilience enhancement strategies and advancing the comprehensive revitalization of mountainous rural areas. [Methods] Using the Yimeng Mountain District as a case study， this study constructed a rural resilience evaluation index system based on the three sustainability dimensions of society， economy， and ecology， and adopted the entropy weighting method， optimal parameter geodetector， and other methodological models to systematically analyze the spatio-temporal pattern and driving factors. [Results] ① From 2000 to 2023， the resilience level of rural county areas in the Yimeng mountainous area showed a fluctuating trend of first decreasing and then increasing， which was generally at a medium level. The spatial pattern was high in the east and west， and low in the middle. The high-toughness areas shrank to the west， while the low-toughness areas expanded from the center to the periphery. ② From 2000 to 2023， the social resilience of the area first decreased and then increased. Economic resilience exhibited a distribution pattern that first decreased and then increased， with higher values in the west and lower values in the east. Ecological resilience exhibited a continuous attenuation trend， with a significantly accelerated attenuation rate over time. ③ The spatial and temporal differentiation of rural resilience in the Yimeng mountainous area was influenced by the natural environment， social economy， regional policy， and other factors. Average fixed asset investment and average fiscal revenue had the highest degree of influence. The influence of road network density， proportion of construction land， and per capita cultivated land area continued to increase. The interactions of various driving factors showed a nonlinear enhancement or two-factor enhancement effect. [Conclusion] Enhancing rural resilience requires moving beyond single-dimensional optimization. A coordinated enhancement mechanism should be established， with ecological resilience as the foundation， economic resilience as the core， and social resilience as the cornerstone， to holistically strengthen the sustainability of mountainous villages in coping with both internal and external disturbances.

Abstract:[Objective] Thespatial characteristics and influencing factors of human settlement suitability in traditional villages of Baoshan City， Yunnan Province were analyze， in order to provide decision-making references and theoretical support for the construction and improvement of human settlements， and to promote the protection， utilization， and sustainable development of mountainous traditional villages. [Methods] Taking 142 national-level traditional villages in Baoshan City as research objects， this study constructed an evaluation system covering 18 indicators across eight dimensions-including topography， climate， and economy-from the perspectives of both natural and human environments. The subjective and objective combination weighting and spatial visualization were employed to evaluate the suitability level and spatial characteristics of human settlements. Furthermore， geodetector and geographically weighted regression models were comprehensively utilized to analyze the dominant factors affecting the human settlement suitability in traditional villages. [Results] ① The comprehensive index of human settlement suitability for traditional villages in Baoshan City approximated a normal distribution and exhibited a relatively pronounced spatial clustering phenomenon. ② Significant interaction was observed among the influencing factors of human settlement suitability in traditional villages of Baoshan City. The synergy between commercial facility density and other factors was the dominant force driving the spatial differentiation characteristics. ③ The influence degree of influencing factors on the human settlement suitability of traditional villages in Baoshan City showed regional differences. [Conclusion] The spatial differentiation characteristics of human settlement suitability in traditional villages of Baoshan City are the results of the combined effects of multiple influencing factors. The influence degree of each factor exhibits regional differences. Therefore， differentiated improvement plans for human settlements should be formulated based on the specific conditions of each traditional village.

Abstract:[Objective] The vegetation carrying capacity of Xi’an-Yan’an high-speed railway（abbreviated as ‘XiYan HSR’） corridor was accurately evaluated， in order to provide a theoretical basis and data support for overall ecological restoration and slope protection along the construction route of this railway. [Methods] The loess regions along the XiYan HSR corridor were taken as study areas. The current vegetation carrying capacity were quantified by integrating the effects of climate， soil texture， vegetation type， slope gradient， and aspect， with particular emphasis on the relationship between vegetation growth and soil water content. [Results] ① Although regional vegetation coverage showed an overall improving trend （with 73.6% of the area experiencing significant increases）， the area in the vicinity of the XiYan HSR was found to be dominated by stable or substantially degraded zones， thereby highlighting the potential ecological pressure induced by railway construction. ② The upper and lower bounds of vegetation carrying capacity across the region range from 18.60% to 100.00% and 4.40% to 100.00%， respectively. Moreover， approximately 77% of the area was found to exceed the carrying-capacity threshold. Specifically， the loess ridge-gully region in the central-west and the Ziwuling low-mid-mountain areas in the north were generally overloaded， necessitating low-intervention strategies focused on soil conservation and maintenance of the current state. In contrast， the southern Weihe Plain， parts of the northern loess tableland， and some northern areas remain below the lower bound， for which measures such as engineering avoidance and supplemental planting are recommended. [Conclusion] To rationally regulate vegetation density， the planting of vegetation on slopes along the XiYan HSR should be constrained by the local carrying capacity.

Abstract:[Objective] The evolutionary trends and regional differences of agricultural green development level in Gansu Province were analyzed， aiming to provide crucial theoretical support for promoting regional agricultural green development and achieving rural revitalization. [Methods] An evaluation indicator system for agricultural green development level was constructed. The entropy weight method was used to measure the agricultural green development level in Gansu Province and its 14 prefectures and cities. Furthermore， kernel density analysis and Dagum Gini coefficient were employed to thoroughly investigate the dynamic evolution and regional differences of agricultural green development level among the prefectures and cities. [Results] ① From 2014 to 2023， the overall agricultural green development level in Gansu Province showed an upward trend， with an increase of 17.65%. Additionally， significant spatial differences were observed in regional agricultural green development level， generally showing gradient distribution characteristics of Hexi region > Longdong region > Longzhong region. ② The period from 2014 to 2016 was the initial stage of agricultural green development in Gansu Province. From 2017 to 2019， the agricultural green development level increased significantly across the province. From 2020 to 2023， it entered a stage of fluctuating adjustment. ③ From 2014 to 2023， the regional differences in agricultural green development level in Gansu Province exhibited a trend of initial rise followed by fluctuating decline， maintaining within a reasonable range （<0.40） overall. The contribution of inter-regional differences was the largest （with an overall contribution rate of approximately 52.33%）， especially between Hexi region and Longzhong region. The disparity between the Hexi region and Longdong region was the primary cause of the imbalance in agricultural green development. [Conclusion] From 2014 to 2023， the agricultural green development level in Gansu Province steadily increased， forming a spatial distribution pattern of ‘Hexi > Longdong > Longzhong’， and went through an evolutionary process of ‘initial development—rapid improvement—fluctuating adjustment’. Currently， the agricultural green development level in the Hexi region is substantially higher than that in the Longzhong and Longdong regions.

Abstract:[Objective] The production-living-ecological functions （PLEF） in western Jilin Province were evaluated， and the evolution characteristics of the coupling coordination degree （CCD） among these functions were revealed， in order to provide a reference for the rational development of the PLEF in this region. [Methods] Using the multi-indicator comprehensive method and CCD model， this study evaluated the PLEF and their spatiotemporal evolution characteristics in western Jilin Province from 2000 to 2023， and analyzed the spatiotemporal variations of the CCD among the PLEF， production—living functions （PLF）， production—ecological functions （PEF）， and living—ecological functions （LEF） from 2000 to 2023. [Results] ① From 2000 to 2023， the PLEF in western Jilin Province showed a significant upward trend， increasing from 20.34 to 44.19 with a growth rate of 66.22%. Specifically， the production function increased with fluctuations by 105.90%， the living function increased by 139.07%， and the ecological function grew by 14.63%. ② From 2000 to 2023， the PLEF and the growth of each function in western Jilin showed significant spatial differences. The comprehensive scores were dominated by increases in the southeastern and central regions. The production function exhibited an evolution pattern of high values in the east and low values in the west， followed by polarization. The living function initially led in the eastern and northern regions and later in the eastern and central parts. The ecological function transitioned from a pattern of increase in the south and decrease in the north to a progressive increase in the southwestern region. ③ The overall CCD showed an upward trend， increasing by 0.16 from 2000 to 2023， rising from a basically coordinated level to a moderately coordinated level. ④ Spatially， the coupling coordination level of the PLEF exhibited a pattern centered on Ningjiang District and Taobei District， gradually decreasing towards the surrounding areas. The coupling coordination level of the PLF showed a pattern of high in the east and low in the west with clustered aggregation. The coupling coordination level of the PEF generally showed an improvement from the surrounding areas towards the urban districts. The coupling coordination level of the LEF showed a fluctuating upward trend， overall showing a gradual improvement from the northeast to the southwest. [Conclusion] The western Jilin region should enhance the economic radiation and driving effect of Ningjiang District and Taobei District， improve the production and living functions of surrounding areas， while continuing to maintain a strong emphasis on ecological functions.

Abstract:[Objective] The spatiotemporal changes and driving mechanisms of net primary productivity （NPP） in the Nanpan River basin of Southwest China were analyzed， in order to provide scientific basis and technical support for ecosystem restoration， water resource management， and optimization of ecological security patterns in the Nanpan River basin and similar mountain-karst ecological regions. [Methods] Based on the improved CASA model， optimal parameters-based geodetector （OPGD）， and geographically and temporally weighted regression （GTWR） model， this study employed Theil-Sen trend analysis， Mann-Kendall trend test， coefficient of variation， and Hurst index to analyze the spatiotemporal distribution characteristics， fluctuation degree， future change trends， interactive effects and driving mechanisms of multiple factors on vegetation NPP in the Nanpan River basin from 2001 to 2023. [Results] ① The vegetation NPP in the Nanpan River basin was predominantly characterized by high-value NPP areas 〔>800 g/（m²·a） （calculated by carbon）〕， accounting for 82.46% of the total river basin area， among which 85.52% of this region showed a continuous increasing trend. Analysis of the coefficient of variation （mean 0.11） indicated that the spatial distribution pattern remained relatively stable， and the persistence analysis of the Hurst index （mean 0.64） further confirmed that NPP changes in this region exhibited significant temporal persistence characteristics. ② OPGD model analysis revealed that the kernel normalized difference vegetation index （KNDVI） （q=0.464 8） and land use type （q=0.382 4） were the primary drivers of vegetation NPP in the Nanpan River basin， among which the interaction between KNDVI and other driving factors had greater explanatory power for NPP changes. ③ The results of GTWR model analysis revealed that the persistent positive driving effect of KNDVI on vegetation NPP across the entire region coexisted with the regional differentiation characteristics of human activities， while the influence of climatic factors such as solar radiation and precipitation on vegetation NPP continued to enhance. [Conclusion] Vegetation NPP in the Nanpan River basin exhibits an overall stable upward trend， driven by vegetation status， land use structure， and climatic conditions. KNDVI plays a central role in multifactor interactions and has become a key indicator affecting regional ecosystem productivity.

Abstract:[Objective] The spatial differentiation patterns of ecological and economic losses in degraded grasslands of West Ujimqin Banner， Inner Monglia Autonomous Region were studied and identify the primary driving factors were identified， in order to provide a scientific basis for decision-making in grassland ecological protection and restoration. [Methods] Taking West Ujimqin Banner as the study area， and based on grassland monitoring data from 2021 to 2023， Landsat 8 OLI， and Sentinel-2 remote sensing images， this study employed a “remote sensing identification + ground verification” technical approach to identify the spatial distribution of grasslands under different degradation levels. An economic loss assessment model incorporating productivity loss and ecosystem service function loss was constructed. Subsequently， methods including principal component analysis and spatial autocorrelation analysis were employed to systematically calculate the scale of economic loss caused by grassland degradation and its spatial heterogeneity. [Results] As of 2023， the degraded grassland area in West Ujimqin Banner reached 8.28×10⁵ hm²， including lightly degraded grassland of 4.28×10⁵ hm² （28.3%）， moderately degraded grassland of 2.66×10⁵hm² （17.6%）， and severely degraded grassland of 1.34×10⁵ hm² （8.8%）， which had not exceeded the critical threshold of irreversible degradation. The total ecological and economic loss caused by grassland degradation reached 2.62×10⁹ yuan， including ecosystem service function loss of 1.50×10⁹ yuan and direct loss from forage yield reduction of 1.12×10⁹ yuan. The loss per unit area was highest in severely degraded grasslands （6，433 yuan/hm²）， while moderately degraded areas contributed the most to the total loss （40.4%）. Principal component analysis revealed that forage yield per unit area， degradation area， and market prices were the dominant driving factors， with a cumulative contribution rate of 89.6%. Economic loss exhibited significant spatial clustering characteristics （Moran’s I=0.426）， with high-loss areas mainly distributed in the northeastern， central-western， and southern regions characterized by high intensity of human activities. [Conclusion] Grassland degradation in West Ujimqin Banner exhibits distinct spatial differentiation characteristics. Moderately degraded grasslands are the primary contributors to economic loss， and human activity intensity is the dominant driving factor. Differentiated protection and governance strategies should be adopted to optimize the regional ecological governance system and achieve sustainable management of grassland ecosystems.