Abstract:[Objective] The effects of sand cover thickness， rainfall intensity， and slope on the formation of water flow， sediment yield， moisture change， and slip in a binary sand and soil structure on loess slopes were analyzed to inform the control and prevention of soil erosion in the wind-water complex erosion area. [Methods] Quantitative analysis was conducted based on laboratory rainfall simulation experiments， through which the processes of runoff， sediment production， erosion， and sliding， as well as spatiotemporal variations in water content on sand-covered loess slopes， were investigated. [Results] ① Sliding phenomena on sand-covered loess slopes were more likely to occur under prolonged rainfall. Moreover， the time of sliding occurrence was delayed on slopes with thicker sand cover， whereas increased rainfall intensity and steeper slopes accelerated sliding. Sediment yield from sliding increased with higher rainfall intensity and steeper slope. ② The variation rate of soil water storage was collectively influenced by sand thickness， rainfall intensity， and slope gradient， and increases significantly with an increase in these three factors. ③ The variation in sand saturation could be divided into three stages： rapid increase， stable state， and renewed growth. ④ Variations in soil saturation indicated that the critical conditions for sliding were influenced by sand thickness， rainfall intensity， and slope gradient. [Conclusion] Sliding on sand-covered loess slopes is substantially influenced by soil saturation， which is controlled by sand thickness， rainfall intensity， and slope gradient.

Abstract:[Objective] The response mechanism of runoff surface sediment and nitrogen and phosphorus loss to rainfall patterns under different holding measure was studied to optimize the scientific configuration of soil and water conservation measures on southern China’s red soil slopes， and provide a theoretical basis for soil and water erosion management in the region. [Methods] Taking the southern red loam area as the study area， based on natural rainfall data from 2019 to 2022， field runoff plot observations were employed to systematically evaluate differently configured soil and water conservation measures， such as orchard clear-tillage control， planting measures （M₁）， cross-slope intercropping （M₂）， down-slope intercropping （M₃）， terracing plus planting （M₄）， and terracing engineering （M₅）. Soil and water conservation measures were configured to systematically analyze runoff sediment characteristics and nitrogen and phosphorus loss in response to rainfall patterns. [Results] The composition of rainfall patterns in the study area was dominated by an advanced pattern comprising short-duration， high-intensity rainfall （41.18%） and an intermediate pattern comprising medium-duration， medium-intensity rainfall （47.06%）， while the delayed pattern of long-duration， low-intensity rainfall accounted for the smallest proportion. Both plant measures （M₁） and terracing plus plant measures （M₅） significantly reduced runoff sediment and losses of nitrogen and phosphorus. Under the advanced pattern， runoff depth and sediment loss were reduced by 61.2% and 91.3% for M₁， and by 58% and 94% for M₅； under the intermediate pattern， runoff depth was reduced by 70.6% and 54.2%， and the amount of sediment was reduced by 80.8% and 82.6%； under the delayed pattern， runoff depth was still reduced by 60.5% and the amount of sediment was reduced by 74.7% for M₁. In terms of controlling nitrogen and phosphorus loss， M₁ and M₅ significantly reduced total phosphorus concentration under all rainfall patterns， with 32.5% and 36.1% reductions in the advanced pattern， and M₅ reduced total nitrogen by 16.3%—21.3%. Downslope intercropping （M₃） increased the amount of sediment （0.424 kg） and total phosphorus concentration （0.127 mg/L） by 42.3% and 53.0%， respectively， under the advanced pattern when compared to CK， because the erosion risk was exacerbated by the matching ridge and slope orientations. [Conclusion] Among different soil and water conservation measures for southern China’s red soil slopes， plant measures and also terraced field projects combined with plant measures， can effectively prevent and control soil erosion under rainy conditions through engineering and the interception and storage of vegetation. Therefore， these measures should be given due attention in soil erosion control on these slopes.

Abstract:[Objective] The water use efficiency of typical woody plants at different slope positions in karst slope habitats were analyzed in order to provide guidance for formulating effective soil and water conservation and ecological restoration measures for karst slopes. [Methods] Using meteorological data， soil mass moisture content， and stable isotope （δ²H， δ ¹⁸O， δ¹³C） data， the water sources and water use efficiency of typical woody plants in three different slope plots in the karst trough valley of Mingyue Mountain， Chongqing were studied. [Results] ① Soil moisture content was higher during the rainy season than during the dry season. In terms of slope position， the average soil moisture content on the upper slope was lower than that on the middle slope， with a difference ranging from 5.07% to 28.41%， and approximately 16.36% to 30.49% lower than that on the lower slope. ② Water from the surface karst zone serves as a critical water source for woody plants at different slope locations. The utilization rates were 34.65%， 25.58% and 20.82% for the upper， middle and lower slopes respectively， during the rainy season， and increased to 54.44%， 53.60% and 43.47% respectively， during the dry season. During the rainy season， the utilization ratio of soil moisture by plants in the 20—40 cm soil layer on the middle and lower slopes was higher than that on the upper slopes. During the dry season， the proportion of soil moisture utilized by plants in the 20—40 cm soil layer on the lower slopes was higher than that on the upper slopes.③ The δ¹³C values and intrinsic water use efficiency （WUE_i） of trees and shrubs were lower during the rainy season than during the dry season. Across different slope positions， the WUE_i of trees was higher than that of shrubs， with the mean WUE_i following the order： upper slope > middle slope > lower slope. [Conclusion] Owing to differences in slope position， the soil moisture content in the karst trough valley increases from the top to the bottom of the slope. When plants on slopes are exposed to water stress， they make greater use of the water in the surface karst zone and exhibit higher water use efficiency.

Abstract:[Objective] The effects of different grass coverage on the stability of soil aggregates in economic fruit forests were explored to reveal the responses of soil properties and aggregates to grass cover in these forest forests and their coordinated regulation mechanisms. [Methods] Soils of economic fruit forests with Vicia villosa （T₁）， Raphanus sativus （T₂）， R. sativus （T₃）， and mixed sowing of V. villosa， R. sativus， and Paspalum wettsteinii （T₄）， were analyzed using the wet sieving and Le Bissonnais methods to assess the effects of grass mulching on the stability of soil aggregates. [Results] ① Under the wet sieving treatment， grass mulching significantly increased the content of water-stable macroaggregates （>0.25 mm）， with T₃ （83.47%）>T₁ （82.20%）>T₄ （79.98%）>T₂ （76.75%）>control （CK； 74.30%）， showing notable increases. Additionally， both the mean weight and geometric mean diameters were significantly higher in the grass-mulched treatments compared to those with clearing tillage. ② Under the Le Bissonnais method， fast wetting （FW） caused the greatest disintegration of aggregates larger than 2 mm， whereas slow wetting （SW） had the least destructive effect， with the percentage of aggregates smaller than 0.25 mm ranging from 15.02% to 23.81%. The highest increase in stability indices was observed with pre-wetting followed by disturbance （WS）. The aggregate stability followed the order： SW>WS>FW. Significant differences were observed between relative slaking index （RSI） and relative mechanical index （RMI）， with RSI being greater than RMI. Among the treatments， the T₂ treatment had the smallest RSI value， whereas the T₃ treatment had the smallest RMI value. ③ The mean soil fractal dimension values under dry and wet sieving treatments were 1.89 and 2.46， respectively. Significant differences were observed in fractal dimension （D）， structural damage rate （PAD）， and unstable aggregates index （E_LT） across different raw herbaceous treatments. The PAD value of the T₁ treatment was reduced by 16.25% compared with that of the CK， and all the treatments of T₁—T₄ significantly reduced the E_LT value. Correlation and pathway analyses indicated that the stability of soil aggregates was affected by total porosity， capillary porosity， bulk weight， soil organic carbon， and mechanical composition， among which soil organic carbon was the key factor. [Conclusion] Grass mulching significantly enhanced the stability of soil aggregates and optimized soil structure in an economic fruit forest by attenuating the dissipative damage caused by heavy rainfall or irrigation on aggregates. Among these， two grass mulching treatments， R. sativus and R. sativus， showed significant advantages in practice.

Abstract:[Objective] Soil moisture characteristics under four vegetation restoration treatments were investigated at different locations of the Hangjinqi photovoltaic power station in the Kubuqi Desert， Inner Mongolia， China， to provide a scientific basis for the rational configuration and management of sand-fixing vegetation in areas with photovoltaic power stations. [Methods] The cutting-ring method was used to determine soil water content at 0—100 cm depth under four vegetation types between and under the panels at different locations （windward side， array belly and leeward side） in the study area and to analyze soil moisture vertical distribution， soil moisture variability， soil water storage and soil water storage deficit. [Results] ① All four vegetation restoration measures increased soil water content， with the average water content in the order of Artemisia ordosica （2.09%） > Leymus chinensis （2.08%） > Glycyrrhiza uralensis （2.06%） > Hedysarum scoparium （1.98%） > bare sand （1.34%）. Spatial distribution was in the order of windward side < leeward side < array belly and interpanel < subplate. Soil moisture was higher under G. uralensis and L. chinensis vegetation restoration than under A. ordosica and H. scoparium vegetation restoration. ② The range of change in soil water storage at 0—100 cm depth under different vegetation restoration measures was 16.72—51.55 mm， and the soil water storage trend was consistent with the soil water content trend. ③ Soil water storage deficit under the different vegetation restoration measures in the photovoltaic power station was in the following order： bare sand （78.81%） > H. scoparium （69.00%） > L. chinensis （68.95%） > A. ordosica （67.23%） > G. uralensis （63.11%）， and decreased with an increase in soil depth， and the spatial distribution was in the order of inter-slab > sub-slab， windward side > leeward side > array belly. [Conclusion] The vegetation restoration measures in the present study increased soil water content in all parts of the soil， and A. ordosica and H. scopariumk had greater effects than the other measures in the 0—30 cm depth range， with lower coefficients of variation. Soil water content， water storage， and water storage deficit under L. chinensis and G. uralensis were superior to those under the other species treatments at depths < 30 cm. Therefore， during the operation and maintenance period， planting A. ordosica and H. scoparium on the windward side， with severe wind erosion， could effectively alleviate wind erosion， and L. chinensis， G. uralensis and other cash crops should be planted in the hinterland and other areas of the array that are less severely affected by wind erosion to address the problem of severe secondary extinction and achieve sustainable development.

Abstract:[Objective] The effects of different soil amendments on improving soil quality in newly cultivated land in Qinba Mountain area were investigated to provide theoretical foundations and technical support for the rapid enhancement of soil quality and restoration of agricultural productivity. [Methods] A two-year field experiment was conducted using five treatments： control （CK）， ferrous sulfate （T₁）， biochar （T₂）， microbial inoculant （T₃） and composite amendment （T₄）. The effects of these treatments on soil quality and maize yield were evaluated in terms of four dimensions： maize yield， soil physical structure， chemical properties and soil enzyme activity. [Results] Compared with CK， maize yields increased by 17.31%， 30.57% and 25.89% in the T₂， T₃， and T₄ treatments， respectively. The ranking of the soil quality indices for each treatment was as follows： T₄ > T₂ > T₃ > T₁ > CK. The soil pH value， bulk density， organic matter， total nitrogen and alkali-hydrolyzed nitrogen levels of the T₂ and T₄ treatments were very close to the corresponding soil indices of high-quality cultivated land in Qinba Mountain area. T₁ treatment improved soil bulk density and T₃ treatment enhanced soil pH value and bulk density to near-optimal levels. Soil organic matter was the key factor influencing soil physical properties， nutrient content， and enzyme activity， whereas low microbial activity was identified as the primary constraint on yield improvement in the newly created farmland. [Conclusion] For comprehensive enhancement of soil quality， biochar （T₂） and composite amendment （T₄） are recommended as key technologies for improving newly created farmlands. However， when considering cost-effectiveness and yield improvement， the microbial inoculant （T₃） is a practical and efficient measure for newly created farmlands in the region.

Abstract:[Objective] The effects of runoff scouring under different slope gradients and land use types on slope runoff， sediment yield， and nitrogen （N） and phosphorus （P） losses were analyzed， in order to provide theoretical support for soil and water conservation in Dabie Mountain region of western Anhui Province， China.[Methods] Field in situ scouring experiments were conducted on 15o and 20o slopes undergoing typical land-use types （bare land， grassland， tea garden， forest land and bamboo forest） in the Jiangzihe small watershed， Huoshan County， Anhui Province. Considering the frequent heavy rainfall in the region， a scouring flow rate of 9 L/min was applied to analyze the responses of runoff， sediment yield and nutrient losses to land-use types and slope gradients. [Results] ① During the scouring process， the stabilized average runoff rate on the 15o slopes was in the following order： bare land > tea garden > grassland > forest land > bamboo forest， whereas the sediment yield rate on the 20o slopes were ranked as follows： bare land > grassland > tea garden > forest land > bamboo forest. Compared to the 15o slopes， the runoff rate on the 20o slopes increased significantly only for bare land， with negligible changes in other land-use types. At a stabilized sediment yield， the sediment yield rate of the 20o slopes was slightly higher than that of the 15o slopes， with both exhibiting the following order： bare land > tea garden > grassland > bamboo forest > forest land. ② Total N （TN） and total P （TP） losses on the 20o slopes were marginally higher than those on the 15o slopes. Under the same slope gradient， TN and TP losses showed the following pattern： tea garden > bare land > bamboo forest > grassland > forest land. ③ Throughout the scouring process， runoff predominantly contributed to TN loss， whereas sediment played a more significant role in TP loss. [Conclusion] Expanding area of bamboo forest cover in the Dabie Mountains of western Anhui Province can effectively enhance water conservation and soil retention. Additionally， tea gardens should be prioritized for non-point source pollution management to mitigate the losses of nutrients， such as N and P.

Abstract:[Objective] Effects of grazing intensity on soil quality and plant diversity in saline marsh wetlands in arid northwest China were investigated to provide a reference for rational grazing and ecological restoration of arid desert wetlands. [Methods] Taking Baidunzi saline marsh wetland in Jingtai County， Gansu Province， China， as the study area， fenced exclusion， light grazing， and heavy grazing zones were established. Plant diversity and biomass were surveyed using the quadrat method， and soil samples were collected from different soil layers to determine aggregate composition， compaction， nutrient content， and physical properties. Principal component analysis （PCA） was used to construct a soil quality index （SQI） to assess the impact of grazing intensity on soil quality， and the structural equation modeling （SEM） was used to analyze the key influencing factors. [Results] ① Fenced exclusion increased plant biomass. β-diversity indices showed significant differences in species composition among different grazing intensities. The proportions of soil water-stable aggregates with particle size >0.25 mm， average mass diameter and geometric mean diameter of surface soil water-stable aggregates in the different grazing treatments were in the following order： no grazing > light grazing > heavy grazing. Soil fertility potential， soil fertility intensity and comprehensive soil quality in the no grazing zone were significantly higher than those in the heavy grazing zone， and there was no significant difference with those in the light grazing zone. SEM results revealed that soil dry sieve geometric mean diameter， soil nutrients （especially nitrogen and potassium）， and capillary water-holding capacity were the main factors affecting soil quality. [Conclusion] Fenced exclusion improved vegetation growth and soil quality significantly. Moderate grazing （light grazing） positively feedbacks to the ecosystem by promoting aggregate stability and nutrient input， whereas heavy grazing leads to soil structure degradation and nutrient loss. A ‘fencing+moderate grazing’ management mode is recommended for prioritizing protection of surface soil physical structure and available nutrients to achieve sustainable restoration of saline marsh wetlands in arid regions.

Abstract:[Objective] This study aimed to predict and evaluate debris flow disasters accompanied by material composition in construction waste sites to diverse mixed ratios of different spoils under heavy rainfall conditions and reveal the chain evolution mechanism and spatiotemporal distribution of the disaster chain in construction waste sites in mountainous areas under extreme rainfall conditions. These results provide a scientific basis for the prevention and control of soil erosion in mountainous regions. [Methods] Five cases （denoted as cases 1—5） comprising five different spoil compositions of miscellaneous fill， silt， and ceramic waste were designed to analyze and simulate debris flows accompanied by typical construction waste sites. Cases 1—5 involved single-material stacking or mixed stacking with different spoil composition proportions. The stability of the dam and slopes formed by the spoil， together with the characteristics of the debris flow after a dam break in the spoil ground， were systematically analyzed. A coupling dynamic model for landslides and debris flows was established using Massflow software. A hazard zonation evaluation of debris flows was performed based on the simulation results provided by the model. The sensitivity of the debris flow characteristics to the key model parameters impacted by the mixing ratios was investigated. [Results] ①The safety factors for the dam were 1.049， 1.002， and 1.034 when extreme rainfall occurred and building spoil ground was fully filled. The values for the filled materials were 1.172， 0.826， and 0.959， respectively. This indicates that extreme rainfall events triggers dam breaks， inducing instability in the filled material behind the dam， leading to debris flow along the downstream channel. ② The numerical simulation results showed that the maximum velocities of the debris flow in cases 1—3 were 21.04， 25.36， and 18.73 m/s，respectively. The maximum mud depths of the debris flows were 19.2， 8.2 and 12.7 m respectively. The farthest accumulation distances of the debris flows in cases 1—3 were 356.0， 674.8， and 545.4 m respectively. The areas of the high-hazard zones of debris flows in cases 1—3 were 36 068.1， 77 254.9， and 82 887.0 m² respectively. ③ A joint analysis of the simulation results of cases 1—5 and ranking of factors （i.e.， internal friction angle > excess pore water pressure coefficient > unit weight） revealed that the internal friction angle and excess pore water pressure coefficient， which were affected by the mixing ratio， were the main controlling parameters for the debris flow characteristics. [Conclusion] Under the conditions of a full reservoir and extreme rainfall， construction waste sites in mountainous areas are associated with a high probability of causing a disaster chain of dam breaks， construction waste site destabilization， and debris flows， posing a serious threat to the safety of downstream residential areas and industrial facilities. The use of a reasonable proportion of materials in a mixed landfill scheme can effectively enhance the overall stability of construction waste sites and significantly reduce the area of high-hazard debris flow zones. A scientifically mixed landfill scheme can effectively control the influence of debris flow.

Abstract:[Objective] The impacts of Yellow River irrigation on physicochemical properties and microbial diversity of saline-alkali soils at Pingluo County， Ningxia Hui Autonomous Region were investigated， in order to provide scientific support for ecological remediation of saline-alkali soils in the region. [Methods] Soil samples from paddy fields at Pingluo County， with different rice planting years （1， 5， 10， and 16 years） during the flooding period （July） and the draining period （October） were analyzed to characterize soil physicochemical properties and bacterial diversity in the salinization of different rice planting years in the two periods by using Illumina Hiseq high throughput sequencing technology. [Results] Soil moisture content， electrical conductivity， soil organic carbon content and total nitrogen content increased significantly with increasing years of rice cultivation. Electrical conductivity， soil organic carbon and total nitrogen increased significantly after 5 years of rice cultivation. The pH value， nitrate nitrogen content and soluble organic nitrogen content decreased significantly with an increasing number of rice cultivation years. The lowest soil pH value after 16 years of rice cultivation in the drainage was 2.66% lower than that in the soil after one year of rice cultivation. The microbial biomass carbon and nitrogen were significantly higher in the soil with rice cultivation for the 16-years paddy soil in the drainage than in the 1-year paddy soil with rice cultivation by 36.28% and 36.59% respectively. Years of rice cultivation had a significant effect on bacterial community diversity and structure. The Chao1 index was 43.99% higher in the soil with rice planted for 16 years during the submerged period than in the soil with rice cultivation for one year. During the submerged period， the relative abundance of Gemmatimonadetes and Spirochaetes increased by 27.46% and 150.00% respectively， in the 10-year paddy soil. The relative abundances of Actinobacteria， Firmicutes and Cyanobacteria significantly decreased by 44.50%， 66.23% and 87.50% respectively， in the 5-year paddy soil. During the drainage period， the relative abundances of Fibrobacteres and Spirochaetes increased by 287.50% and 314.29% respectively， in the 5-year paddy soil. The relative abundances of Chloroflexi and Chlorobi increased by 46.35% and 370.97% respectively， in the 10-year paddy soil. The relative abundances of Actinobacteria， Nitrospirae and Armatimonadetes significantly decreased by 48.10%， 55.34% and 65.85% respectively， in the 5-year paddy soil. At the genus level， the relative abundances of Pseudanabaenaceae and Comamonadaceae decreased significantly by 96.89% and 56.60% respectively， in the 5-year cultivated soil during the submerged period. The relative abundances of Caldilineaceae and Desulfobulbaceae significantly increased by 64.86% and 305.26% respectively， in the 10-year cultivation soil during the submerged period. Redundancy and Pearson correlation analyses showed that soil conductivity， total nitrogen， nitrate nitrogen， ammonium nitrogen， dissolved organic carbon and dissolved organic nitrogen were the key environmental factors affecting bacterial community structure in saline paddy soil. [Conclusion] Significant changes in the soil bacterial communities and physicochemical properties were observed with an increase in the number of rice cultivation years， and the soil habitat showed an improving trend.

Abstract:[Objective] Soil moisture characteristics， nutrient changes beneath photovoltaic （PV） panels in rocky desertification areas， and their key influencing factors were analyzed. The effects of PV panel height and terrain slope on soil physicochemical properties during the dry season were evaluated to provide a scientific basis and theoretical support for ecological restoration and green industry development in this region. [Methods] A PV demonstration base in Shilin Yi Autonomous County， Yunnan Province， which had been under construction for 8 years， was selected as the study area， and soil samples were taken from beneath PV panels of differing heights （high panel： front eave height 2.4 m， rear eave 3.1 m； low panel： front eave height 0.5 m， rear eave 1.2 m； tilt angle of 24°） on both flat slopes and steep slopes during drought period. The responses of soil moisture and nutrients to PV panel heights in association with different slope gradients were analyzed using analysis of variance （ANOVA） and redundancy analysis （RDA）. [Results] ① In karst rocky desertification areas during the dry season， PV panel height significantly influenced soil moisture and nutrient content （p<0.05）. Compared with non-shaded areas， PV panel shading was associated with significantly increased soil volumetric water content， saturated water-holding capacity， capillary water-holding capacity， and field capacity. Notably， soil moisture levels beneath low PV panels on shallow terrain gradients were consistently higher than those at the other sampling sites. ② Soil total nitrogen （TN） and total phosphorus （TP） contents exhibited significant decreases with increasing PV panel height throughout the dry season， and displayed maximum values beneath low PV panels on flat slopes. However， soil organic carbon （SOC） content in shaded areas decreased by 35% compared with control regions by the end of the drought period. ③ Correlation analysis revealed that PV panel installation primarily altered soil bulk density， porosity， pH value， and enzyme activities， thereby driving changes in soil moisture and nutrient characteristics. [Conclusion] The construction of low-PV panels in rocky desertification areas during the dry season was more conducive to reducing water evaporation and fixing nutrients compared to high-PV panels， especially in flat slope areas.

Abstract:[Objective] The spatiotemporal variation patterns of vegetation during the dry season and their response to drought resistance under different ecological restoration patterns were explored to provide fundamental data and theoretical support for vegetation ecological restoration in Honghe dry-hot valley. [Methods] Three types of restoration patterns were taken as study cases： an artificially constructed arbor-shrub-grass stereoscopic restoration terrace （ASH） that had been restored for three years， naturally restored land post artificial terrace development （NET）， and naturally restored shrub-grassland （SG）， with degraded land （DG） as the control. Fixed sample plots were established， and a combination of vegetation community surveys， drone monitoring and microclimate recording was used to compare species composition， species diversity， vegetation coverage and microclimate characteristics between different plots at the beginning and end of the dry season. [Results] ① Species diversity： During the dry season， ASH exhibited minimal changes in species composition， with high species diversity and no clear dominant species. NET exhibited high species evenness but relatively low species richness. SG experienced significant changes in species composition， with both species richness and evenness showing significant declines by the end of the season. ② Vegetation coverage： At the beginning of the dry season， the total fractional vegetation cover （FVC） ranked as ASH > NET > SG > DG， and this pattern remained consistent at the end of the dry season. The degree of change in FVC between the beginning and end of the dry season was greatest in NET， followed by ASH， with DG showing the least change. ASH had significantly higher coverage across all vegetation layers compared to other plots. ③ Microclimate regulation： During the early and late dry seasons， the ASH vegetation exhibits lower temperatures and higher humidity characteristics compared to other vegetation types. [Conclusion] The arbor-shrub-grass stereoscopic vegetation structure demonstrates significant advantages in regulating microclimate and maintaining ecological stability， and therefore making it suitable for promotion in regions with extreme climatic conditions， such as dry-hot valleys.

Abstract:[Objective] Soil quality of plantation forests in the north China Plain was quantitatively evaluated， in order to provide a scientific basis and references for the related soil quality improvement and limiting factor diagnosis in the region. [Methods] Populus spp. plantations with different densities （i.e.， 1 111， 833， 625， 555， and 416 trees/hm²） were taken as cases. Soil samples were collected from the 0—20 cm depth layer of the soil in poplar forests in late October， 2024. The main physicochemical soil properties and related enzymatic activities were analyzed. The minimum dataset was selected based on principal component analysis. Soil quality was evaluated using the soil quality index and limiting factor diagnosis. [Results] ① Based on the principal component analysis of the total dataset， a minimum dataset was established， consisting of soil total carbon， sucrase activity， electrical conductivity， silt content and available phosphorus. ② The soil quality indices of poplar plantations with different densities were ranked as follows （trees/hm² ， followed by values in brackets）： 416 （0.55） > 555 （0.51） > 625 （0.49） > 1 111 （0.48） > 833 （0.44）. Stand density significantly affected the soil water content， pH value， organic carbon， total carbon and available nutrient values. ③ Soil quality limitations in the study area were primarily moderate and mild. Soil organic carbon （15%） and water contents （13%） were the most significant soil quality-affecting limiting factors. All poplar plantations faced limitations related to soil nutrient and water availabilities. [Conclusion] Soil quality was optimal in poplar plantations at a density of 416 trees/ hm². All poplar plantations in the north China Plain face challenges of insufficient soil nutrients and water scarcity. Therefore， developing scientific fertilization and irrigation management practices and determining appropriate afforestation densities in plantation practices would be essential to achieve sustainable soil utilization.

Abstract:[Objective] Wind tunnel simulation tests of high-density polyethylene（HDPE） board fences with the same hole diameter but different opening directions were conducted in order to provide a theoretical basis for the better application and better effect of HDPE board sand-blocking fences. [Methods] Wind tunnel simulations compared wind speed profiles， aerodynamic parameters， flow field characteristics and windbreak efficiency between fences featuring holes oriented horizontally versus vertically. The analysis focused on the impact of hole orientation （horizontal vs. vertical） on windproof performance. [Results] Both fence types exhibited logarithmic wind speed distributions at -1 H （H = fence height of 23 cm） upwind and 9 H downwind （p<0.05）. The vertical hole configuration demonstrated superior profile stability， with higher aerodynamic roughness and greater friction speed than its horizontal counterpart. Flow field analysis revealed that the horizontal fence exhibited notable near-surface acceleration zones （from -1 H to 2 H）， and its deceleration zone split into two parts （1—5 H and 8—15 H） in response to increased wind speed. However， the vertical fence effectively regulated sand transport through controlled speed gradient attenuation， and its deceleration zone changed little with the increase in wind speed. In particular， the vertical fence’s deceleration zone maintained stable aerodynamic characteristics across the wind speed regimes. Windbreak efficiency progression showed three phases： a moderate improvement of 5.1%—8.4% （from -7 H to -1 H）， abrupt decline of 43.3%~55.6% （from -1 H to 1 H）， and a gradual increase in stability （43.3%—55.6%） post -1 H. At higher wind speeds， the windbreak efficiency of the vertical fence was 50.4% higher than that of the horizontal fence （p<0.05）. Notably， the efficiency of the horizontal fence decreased by 45.6% with increasing wind speed （p<0.05）， whereas the vertical fence maintained consistent performance （p>0.05）. [Conclusion] HDPE fence with vertically oriented holes demonstrated superior comprehensive wind speed reduction capacity， remarkable flow field stability， and maintained performance across variable wind conditions， indicating significant potential for large-scale application in sand control and desertification prevention engineering.

Abstract:[Objective] The disaster reduction effects of the debris-flow check dam on downstream structures under varying rainfall frequencies were investigated to offer guidance for disaster prevention and mitigation in villages and towns. [Methods] First， a field investigation of the ‘7 · 12’ Heishui gully debris-flow event in Pingwu County， Sichuan Province， China， was conducted. Second， based on the ultimate bearing capacity of masonry walls under debris flow impact， critical velocity formulas for bending failure and shear failure of brick masonry walls were proposed using static equilibrium methods. Finally， the debris-flow movement process and deposition extent in Heishui gully， both with and without the check dam and under varying rainfall frequencies， were simulated using FLO-2 D. [Results] ① The scale of debris-flow discharge， sediment deposition depth and flow velocity were intricately linked to the frequency of rainfall， with a simulation accuracy of 85% in comparison to the field investigation data. ② The wall suffered bending damage due to the overall pressure of debris-flow slurry and shear damage from the impact of large boulders. ③ In the absence of a check dam and at a rainfall frequency of 1%， the debris-flow deposition area was 9.36×10⁴ m²， the maximum flow velocity in the construction zone reached 7.19 m/s， and the maximum debris-flow depth in the construction zone was 5.25 m. At a rainfall frequency of 2%， the debris-flow deposition area was 5.63×10⁴ m²， the maximum flow velocity in the construction zone reached 5.63 m/s， and the maximum mud depth in the construction zone was 4.46 m. ④ After the check dam was constructed， the debris flow did not reach the outlet under the 2% rainfall frequency， resulting in an 82.6% reduction in the deposition area. Under the 1% rainfall frequency， the debris-flow deposition area and maximum flow velocity in the construction zone were diminished by 38.4% and 60.6%， respectively. [Conclusion] Prevention and control measures can significantly reduce the magnitude of disasters and prevent buildings from being damaged. However， monitoring and early warning systems require enhancement throughout the rainy season.

Abstract:[Objective] The effects of microbial inoculants on soil water-retention capacity and plant growth-promotion mechanism in desertified soil were explored in order to provide references for water-retention capacity improvement and sustainable agricultural development. [Methods] Three Bacillus spp. were used. By combining indoor infiltration evaporation experiments with field experiments， the effects of different microbial inoculants on desertified soil were comprehensively evaluated using indicators such as soil water retention performance， aggregate composition， enzyme activity， and plant physiology. [Results] Compared with the control group， the triple and dual bacterial inoculant treatments increased the proportion of large aggregates （0.25 mm） by 23.09% and 32.51%， respectively. The triple bacterial inoculant treatment increased the organic carbon content by 2.96 g/kg， and the total and alkali-hydrolyzed nitrogen， and available phosphorus and potassium contents by 21.54%， 61.50%， 312.16% and 30.17%， respectively. The effects of different bacterial inoculants on soil enzyme activity vary. The triple bacterial inoculant treatment significantly increased peroxidase and sucrase activity and significantly promoted plant growth， which manifested as a significant increase in plant height， root length， proportion of underground biomass， and the root cap increased by 5.0% compared with the control treatment. [Conclusion] Bacillus inoculants can effectively improve desertified soil and achieve growth-promotion effects by improving the soil structure， reducing water evaporation and increasing nutrient content. Among them， the triple bacterial inoculant treatment showed a significantly improved synergistic effect than a single bacterial inoculant treatment in promoting plant growth.

Abstract:[Objective] The comprehensive effects of different intercropping methods of four perennial forage grasses on growth， photosynthesis， and soil moisture in the Loess Plateau were analyzed. Screening of the optimal intercropping method was also done to provide theoretical support for establishing high-yield， efficient， and sustainable artificial grasslands in the Loess Plateau. [Methods] Four perennial forage grasses （Medicago sativa， Bromus inermis， Elymus dahuricus， and Astragalus adsurgens）， with intercropping of one （n=4）， two （n=4）， three （n=2）， and four （n=1） species were established to analyze the growth， photosynthetic， and water use characteristics of the forages under the different mixture patterns. [Results] The total relative yield of all intercropping treatments exceeded one. The intercropping treatment of M. sativa and B. inermis achieved a total relative yield of 2.08. This treatment increased the biomass of B. inermis and M. sativa to 279.1% and 132.4%， respectively， compared to their monoculture. Intercropping of M. sativa and B. inermis significantly increased the net photosynthetic rate and transpiration rate of M. sativa （p<0.05）. There was no significant effect on the net photosynthetic rate of B. inermis， but leaf water use efficiency increased significantly （p<0.05）. This intercropping also increased the water content of the deep soil. Entropy-weighted TOPSIS evaluation revealed that the M. sativa and B. inermis intercropping produced the best comprehensive effects in terms of forage yield， growth physiological characteristics， water and soil resource utilization efficiency， and soil water storage capacity. The comprehensive effect of gramineous monoculture was the worst. [Conclusion] Reasonable intercropping configurations can optimize vertical soil moisture distribution and enhance forage net photosynthetic rate， thereby improving system productivity and water utilization. Intercropping of M. sativa and B. inermis could effectively enhance production capacity and water use efficiency， providing valuable practical guidance for optimizing forage intercropping systems in semi-arid regions of the Loess Plateau.

Abstract:[Objective] The contribution rates and composition of each factor in runoff depth were quantified to analyze the contribution rates of underlying surface， climate， and industrial and agricultural water use change to runoff change in the source region of the Yellow River， in order to provide references for ecological environment protection and water resource development in the Yellow River basin. [Methods] Based on the meteorological and hydrological data of the source region of the Yellow River from 1970 to 2021， the distributed water-heat coupled model WEP-ISF was used to analyze the dynamic changes in monthly average flow， actual evapotranspiration， soil temperature， soil moisture content and runoff components in different periods in the source region of the Yellow River， and the multi-factor attribution analysis method was used to quantitatively analyze the contribution of each influencing factor to the variation in runoff volume. [Results] ① Simulation and verification of the hydrological and water-heat change process in the source region of the Yellow River from 1970 to 2021 by using the WEP-ISF model showed that the average absolute percentage error between the simulated soil temperature and remote sensing interpreted value was between 69.78% and 171.55%， and the Nash efficiency coefficient was more than 0.70； the average absolute percentage error between the simulated surface soil moisture content and remote sensing interpreted value was between 13.94% and 20.97%， and the Nash efficiency coefficient was more than 0.5； the Nash efficiency coefficient and average absolute percentage error between the simulated monthly average flow and measured value were 0.80 and 25.85%， respectively； and the Nash efficiency coefficient and average absolute percentage error between the simulated actual evapotranspiration and remote sensing interpreted value were 0.80 and 53.39%， respectively. ② The multi-year average runoff from glaciers， snowmelt， and precipitation in the source region of the Yellow River was 0.9， 14.9， and 70.5 mm， accounting for 1.0%， 17.3%， and 81.7%， respectively， of the runoff depth in the source region of the Yellow River. Compared with the baseline period of 1970—1990， the change in runoff from glaciers， snowmelt and precipitation during the change period of 1991—2021 was 1.48， -3.8， and -13.2 mm， respectively， accounting for 9.53%， -24.48%， and -85.05%， respectively， of the change in the runoff depth of the source region of the Yellow River. ③ The multi-year average runoff at Tangnaihai decreased by 6.77×10⁹ m³， among which the contribution rates of climate， underlying surface， and industrial and agricultural water use changes were 96.46%， 2.49%， and 1.05%， respectively. [Conclusion] Among the many factors affecting runoff change in the source region of the Yellow River， climate is the main driving factor leading to runoff attenuation， which is manifested in the trend of increasing glacier melt water flow and decreasing trend of snowmelt runoff and runoff.

Abstract:[Objective] To address the inefficiencies of traditional approaches for monitoring the soil moisture content （SMC） and soil organic matter content （SOMC） in saline-alkaline farmlands， an estimation method that integrates hyperspectral data with interpretable machine learning was investigated. The goal was to establish a theoretical foundation for the rapid acquisition of soil information and quality assessments of the Hetao Plain， China. [Methods] Ground-based hyperspectral reflectance data and field-measured SMC and SOMC were used as the primary data sources. Spectral data were processed using a fractional-order differential （FOD） transformation， and various spectral indices were constructed. The models were developed using partial least squares regression （PLSR）， support vector machines （SVM） and random forest （RF）. To enhance interpretability， the Shapley additive explanations （SHAP） method was employed to evaluate the relative contribution of each variable to model predictions. [Results] ① The spectral indices derived from the 1.25-order differential transformation showed the highest correlation with the SMC and SOMC. In particular， the generalized difference index （GDI） and optimal spectral index （OSI） exhibited the strongest correlations， with coefficients of 0.505 4 and 0.682 5， respectively. ② The RF model significantly outperformed the PLSR and SVM models in estimating both the SMC and SOMC. For the validation datasets， the RF models achieved R² values of 0.734 and 0.870， root mean square errors of 3.28 and 1.53， and recognition-primed decisions of 2.07 and 2.43 for SMC and SOMC， respectively. ③ The SHAP analysis indicated that the normalized plane domain index （NPDI） and ratio index （RI） were the most influential variables for estimating the SMC and SOMC， respectively. The combined contributions of the NPDI， OSI and difference index （DI） to SMC modeling reached 68.58%， whereas RI， GDI and NPDI collectively contributed 61.86% to SOMC modeling. [Conclusion] The integration of FOD and spectral indices enhanced the utility of hyperspectral data. The RF model demonstrated superior accuracy and robustness in estimating soil properties， whereas the SHAP analysis effectively elucidated the contribution of individual variables. Spectral indices （such as NPDI， RI， OSI and DI） played significant roles in modeling SMC and SOMC in saline-alkaline farmland.

Abstract:[Objective] The ecological security pattern （ESP） of the Keriya River basin was constructed to provide a scientific basis for optimizing ecological security， restoring ecosystems， and establishing ecological protection systems in the region. [Methods] Taking the Keriya River basin as a study area， the InVEST model was employed to quantitatively evaluate the importance of key ecosystem services， including water conservation， soil retention， habitat quality， and carbon storage. An ecological sensitivity evaluation system was developed to assess regional ecological sensitivity and identify ecological sources. A minimum cumulative resistance model was used to construct an ecological resistance surface， and ArcGIS software was applied to delineate ecological corridors， ultimately forming the ESP of the basin. [Results] The Keriya River basin contains two ecological sources， with a total area of 4 610.47 hm²， located in the forested and grassland regions in the central and southern parts of the basin. Three ecological corridors， with lengths of 582.75， 113.43， and 65.11 km， were identified. These corridors are crucial for facilitating species movement， conserving soil and water， and enhancing biodiversity. [Conclusion] Desertification control and sustainable forest management are paramount for the ecological environment of the Keriya River basin. Rational water resource allocation， the selection of vegetation suited for sand fixation， and development of economically valuable desert oases are essential to support ecological restoration and provide financial sustainability for the region.

Abstract:[Objective] The changing patterns of plant diversity in the Daqing Mountain Nature Reserve in Inner Mongolia under different environmental factors were analyzed. And the relationship between plant diversity in mountainous areas and the environment was clarified， in order to provide a scientific basis for the research， evaluation， protection and comprehensive management of the diversity in mountain ecosystems. [Methods] The deep learning algorithm were employed to construct a plant diversity index model， and the model accuracy was validated. Subsequently， the spatial distribution of plant diversity in Daqing Mountain was predicted， and the various patterns of plant diversity under different environmental factors were analyzed. [Results] ① There were a total of 108 plant species in the study area， belonging to 77 genera and 31 families. The plant diversity on the shady slopes was greater than that on the sunny slopes. ② The slope had the greatest relative contribution （42%） to the Shannon-Wiener index （H’）， Simpson dominance index （D） and Pielou evenness index （J）， followed by temperature vegetation dryness index （TVDI， 25%）， temperature （17%）， NDVI （8%） and solar radiation （8%）. Temperature and solar radiation had the largest relative contribution to the Margalef richness index （R） （38%）， slope （9%）， aspect （8%）， and NDVI （7%）. ③ The predicted results of H’， D， J， and R all showed strong agreement with measured values， with mean absoute error （MAE） values of 0.08， 0.03， 0.03， and 0.05， and mean square error （MSE） values of 0.020， 0.003， 0.002， and 0.004， respectively. Further linear regression analysis between simulated and observed values in the training set revealed that the R² values for each diversity index reached 0.86， 0.93， 0.92， and 0.99， respectively. ④ The value range of H’， D， J and R in the Daqing Mountain were 3.87， 0.83， 0.95 and 4.12， respectwely. ⑤ H’， D， and J were linearly negatively correlated with slope， TVDI， land surface temperature （LST） and solar radiation， and linearly positively correlated with NDVI. R was linearly negatively correlated with LST， solar radiation and slope， and linearly positively correlated with aspect and NDVI. Overall， plant diversity was linearly negatively correlated with LST， solar radiation and slope， and linearly positively correlated with NDVI. [Conclusion] Deep learning methods can be feasibly used to predict the spatial distribution of plant diversity in mountainous landforms. This method can deepen our understanding of the complex relationship between plant diversity and environment.

Abstract:[Objective] The research progress of soil conditioners in preventing and controlling soil erosion in the red soil area of southern China was analyzed， in order to provide theoretical references for the control and management of soil erosion in the red soil area of southern China. [Methods] Based on RStudio and ArcGIS visualization tools， Keyword combinations centered on ‘soil amendments’ ‘soil erosion’ and ‘red soil regions of southern China’ were constructed to retrieve relevant literature published between 1999 and 2024 from the China National Knowledge Infrastructure and Web of Science databases. A quantitative analysis was conducted， focusing on the number of publications， research institutions， journals， application frequency of amendments， experimental methods and application durations， study locations， and evolution of keywords. [Results] ① From 1999 to 2024， there was a rapid increase in the number of publications related to soil amendments for erosion control， reflecting the growing interest among researchers in this field. ② Straw， organic fertilizers and biochar emerged as the most frequently used materials because of their effectiveness in improving soil organic matter content， enhancing aggregate stability， and increasing water retention capacity. ③ Related studies were primarily focused on regions with severe soil erosion， such as Jiangxi and Hunan provinces. ④ Soil amendments could be categorized into four major types： natural， synthetic， natural-synthetic copolymer， and biological amendments. The practical effects of soil amendments in enhancing soil aggregate stability， erosion resistance， water retention capacity and ecological restoration were obvious. [Conclusion] In the red soil regions of southern China， future studies should focus on the interaction between improvers and environmental factors （such as climate and soil type）， to develop new types of compound soil amendments， and comprehensively evaluate their long-term ecological effects to promote the sustainable management of agricultural ecosystems.

Abstract:[Objective] The spatiotemporal change characteristics of land use in China and each province under different carbon emission scenarios were systematically analyzed， in order to provide data support and theoretical basis for formulating regional land use planning and policies to cope with climate change， as well as future land use planning and sustainable development in China. [Methods] Based on land use data from 2015 to 2100， combined with land use transfer matrix and dynamic attitude index， this paper analyzed the temporal and spatial characteristics of land use change in China. [Results] ① Under SSP126 （low carbon emission） and SSP245 （medium carbon emission） scenarios， cultivated land， construction land and unused land showed an overall increase trend， while grassland and forest land decreased， and grassland decreased most significantly. Under the SSP585 （high carbon emission） scenario， cultivated land， grassland and construction land increase， while forest land and unused land decrease significantly. In terms of land use transfer， forest land was converted into cultivated land and grassland， and unused land and grassland were converted most frequently. ② From 2015 to 2030， the land use change is the most drastic， and the dynamic attitude under the SSP585 scenario is the highest， which is mainly manifested as the conversion of grassland and unused land into cultivated land and construction land. ③ From 2030 to 2060， the change amplitude decreases， and the change in the western region is relatively stable， and the change in Sichuan， Gansu and Heilongjiang provinces tends to be stable under the SSP245 scenario. ④ From 2060 to 2100， the impact of climate change will weaken， and the total change area will decrease significantly. Especially under the SSP585 scenario， the change of western provinces is still more obvious， while the change of eastern regions will slow down. [Conclusion] China’s land use change would be affected by carbon emission scenario， regional economic development and urbanization process， showing significant spatiotemporal heterogeneity and regional differences.

Abstract:[Objective] The spatiotemporal variation of agricultural carbon emissions and its main influencing factors in the Yellow River basin were scientifically evaluated to predict the future emission trend， and provide data support and decision-making reference for formulating agricultural carbon emission reduction policies and regional collaborative governance plans. [Methods] The agricultural carbon emissions from 2001 to 2021 were selected from nine provinces of the Yellow River basin， the STIRPATextended model（stochastic impacts by regression on population， affluence and technology） was used to analyze the driving factors， and the GM （1，1） model was used for forecasting. [Results] ① Significant differences were observed in agricultural carbon emissions among provinces and regions in the Yellow River basin， and the agricultural carbon emissions in major grain-producing areas were significantly higher than those in other provinces. ② Agricultural carbon emissions in the Yellow River basin first increased and then decreased over time， showing an overall ‘inverted U-shape’. The quarter-on-quarter growth rate showed a fluctuating rise in the early stage and then began to decline slowly after 2012 until a negative growth in 2017， indicating that policy intervention played an important role in agricultural carbon emission reduction. ③ Among the driving factors of agricultural carbon emissions in the Yellow River basin， agricultural production efficiency， economic development level， urbanization level， agricultural land management scale and agricultural mechanization level were the main factors leading to the increase of agricultural carbon emissions. The energy intensity of agricultural machinery had a restraining effect on carbon emissions， and the technological progress may offset part of the carbon emission reduction effect due to the ‘rebound effect’. ④ From 2022 to 2035， agricultural carbon emissions in the Yellow River basin may exhibit a downward trend， while maintaining a high level， and agricultural carbon emission reduction pressure would remain large. [Conclusion] The potential of agricultural carbon emission reduction in the Yellow River basin has not been fully realized， and agricultural carbon emission reduction should be further achieved by accelerating the application of new energy technologies， popularizing green and low-carbon production technologies， building a whole-chain management system of agricultural waste， promoting the optimization of agricultural structure and the innovation of the coupling model of planting and breeding， and building a collaborative development system of ecological and organic agriculture based on local conditions. At the same time， it is necessary to establish a dynamic balance mechanism between economic growth and emission reduction targets to avoid the risk of carbon emissions rebound caused by extensive development.

Abstract:[Objective] The spatiotemporal evolution dynamics of carbon emissions from energy consumption in the development and utilization of agricultural water and land resources in central China were studied to identify the key drving factors and provide theoretical and data reference for promoting low-carbon green transformation and agriculture development in central China， and to achieve the ‘dual carbon’ goal. [Methods] Carbon emissions from energy consumption during utilization of agricultural water and land resources were investigated based on social and economic data from six provinces in central China from 2010 to 2022. The IPCC carbon emission coefficient method was used to measure agricultural carbon emissions in central China from 2010 to 2022. The drivers and contributions of agricultural carbon emissions were discussed based on the Kaya identity and logarithmic mean divisia index. ArcGIS visualization was used to analyze the evolutionary trend of agricultural carbon emissions in central China in the spatiotemporal dimensions， and the relationship between matching degree of water and land resources and agricultural carbon emissions was explored. [Results] ①During 2010—2022， the total agricultural carbon emissions in central China increased rapidly and then fluctuated downward. The growth rate of agricultural carbon emissions experienced a gradual decline during the evolutionary process. ② Agricultural carbon emission intensity was the key factor promoting agricultural carbon emission reduction in central China， and the economic output of agricultural water resources was the primary factor driving growth of agricultural carbon emissions. The cumulative contribution of agricultural carbon emissions during 2010—2022 reached 5.62×10⁶ t. The contributions of economic output factors of agricultural water resources and water consumption per unit sown area to agricultural carbon emissions in central China varied in both positive and negative directions. ③ Improving the matching degree of agricultural water and land resources could facilitate curbing of agricultural carbon emissions； however， the impacts on agricultural carbon emissions in different provinces varied. [Conclusion] In future， attention should be paid to spatiotemporal matching of water and land resources and their eco-environmental effects， adopting different farming modes according to local conditions， optimizing allocation， which would enhance sustainable development and utilization of agricultural water and land resources and promote low-carbon transformation in agriculture.

Abstract:[Objective] The effects of 12 different exogenous organic materials， including tobacco stalk biochar， fruit tree branch biochar， wheat straw， rapeseed straw， chicken manure， cow manure， glucose， cellulose， LB medium， polyacrylamide （PAM）， humic acid fertilizer and chitosan， on the physicochemical properties and soil organic carbon fractions of typical loess （black loessial and loessial soils） were studied to provide a theoretical basis for selecting and applying organic soil conditioners to improve the quality of cultivated soil. [Methods] Organic materials were mixed with air-dried soil at a mass ratio of 3%， and a 100-day indoor incubation experiment was conducted using a control group （CK） without organic material addition. Density flotation combined with wet sieving was used to separate and quantify four organic carbon fractions： free particulate organic carbon （FPOC）， occluded particulate organic carbon （OPOC）， particulate organic carbon （POC）， and mineral-associated organic carbon （MOC）. Redundancy analysis was performed to analyze the relationships between soil physicochemical properties and organic carbon fractions. [Results] ① Compared with CK， the addition of organic materials effectively reduced the calcium carbonate content of the two typical loess soils and increased the soil electrical conductivity， TOC and total nitrogen （except for cellulose addition）. ② Compared with CK， the contents of FPOC， OPOC， POC， and MOC in the soil increased， with the largest increments in FPOC observed under treatments with fruit tree branch biochar， tobacco stalk biochar and wheat straw. In black loessial soil， the corresponding indicators increased by 2 158.5%， 1 545.3%， and 907.5%， respectively， whereas in loessial soil， the increases were 2 971.8%， 1 717.9% and 1 730.8%， respectively. ③ A highly significant positive correlation was noted between FPOC， OPOC， POC， MOC contents and TOC （p0.01）. The C/N ratio and total nitrogen content were the primary factors influencing the organic carbon content of the soil components， with explanation rates reaching 76.1% and 76.3% in black loessial and loessial soils， respectively. [Conclusion] The addition of organic materials increased TOC content， and effectively improved soil physicochemical properties. Compared with CK， the contents of FPOC， OPOC， POC， and MOC in the soil increased. The C/N ratio and total nitrogen content were the dominant factors influencing the organic carbon content of the soil components.

Abstract:[Objective] The effects and mechanisms of soil carbon and nitrogen sequestration during vegetation restoration in desertification reversal was revealed in order to provide a scientific basis for evaluating the restoration effects of sand fixation afforestation on desertified soil quality. [Methods] Sand fixation forests of shrubs and trees in the Mu Us sandy land of Yulin City， Shaanxi Province， including changing sandy land， semi-fixed sandy land and those restored for 20—50 years were selected. Using the centrifugal group method， the characteristics of content evolution， density growth rate and contribution ratio of carbon and nitrogen in the soil and the combined state of sand， silt， and clay mineral particles in the 0—10 cm and 10—20 cm soil layers were explored. [Results] With prolonged restoration， sand-fixing forests substantially enhanced the densities of total organic carbon （TOC）， total nitrogen （TN）， and mineral particle-bound carbon/nitrogen， exhibiting linearly increasing trends. Sand fraction showed the highest carbon accumulation rate 〔0.14 Mg/（hm² · a）〕， followed by silt， whereas clay exhibited the lowest rate. After 50 years of restoration， arbor forests displayed 26.9% and 18.5% higher TOC and TN contents， respectively， than shrublands. In surface soils （0—10 cm）， the carbon content in sand， silt， and clay particles increased by 13.75， 11.37， and 5.24 times in shrublands relative to that in mobile dunes， respectively， reaching 13.73， 24.78， and 5.82 times increments in arbor forests. The surface layers of arboreal forests demonstrated significantly stronger carbon and nitrogen sequestration capacity in sand and silt particles than those of shrublands， whereas no significant differences were observed in clay particles and subsurface layers. Although sand particles contributed 42.36%—48.70% of total carbon-nitrogen increments， the combined silt and clay fractions （representing only 8.1% of total soil mass） accounted for 56.12% of organic carbon and 57.13% of TN sequestration， showing the characteristics of ‘low quantity and high efficiency’. The soil C/N ratios exhibited a unimodal pattern with the restoration chronology peaking in 20—30 years. Silt particles maintained the highest C/N ratios （26.6—39.9）， contrasting with the lowest values in clay fractions （10.7—18.4）， indicating substantial compositional differences in mineral-associated organic matter. [Conclusion] These findings highlight the critical role of vegetation restoration in enhancing soil carbon and nitrogen sequestration via accelerated sand particle accumulation and effective silt-clay adsorption mechanisms in desertification-controlled ecosystems.

Abstract:[Objective] The effects of different preparation temperatures for hydrochars from sunflower straw on soil organic carbon （SOC） and its components were investigated to provide a theoretical basis for sunflower straw resource utilization and soil carbon sequestration. [Methods] Hydrochars （SB180 and SB220） were prepared from sunflower straw at 180 ℃ and 220 ℃， respectively， and indoor incubation tests were conducted to analyze the differential regulation of SOC and its fractions by varying preparation temperatures and additive amounts of hydrochar input. [Results] ① The carbon content， aromaticity， specific surface area， and pore volume of the hydrochars gradually increased with increasing preparation temperature. ② The contents of SOC， mineral-associated organic carbon （MAOC）， and particulate organic carbon （POC） significantly increased with increasing preparation temperature and addition amount. SOC， POC and MAOC reached their highest levels in the 2% SB220 treatment， increasing by 75.34%， 23.34% and 105.75%， respectively， compared with CK. ③ As the preparation temperature increased， the soil organic carbon mineralization rate， cumulative mineralization amount， potentially mineralizable carbon （C_p） and priming effect （P_E） decreased， whereas these values increased with higher addition amounts cumulative mineralization， C_p and P_E were elevated by 50.88%， 57.61% and 79.51%， respectively， in 2%SB220 treatment compared to 1%SB220 . [Conclusion] SB220 can significantly enhance the contents of SOC， MAOC and POC， and exhibits strong carbon sequestration potential； however， the risk of carbon emissions increases with the increase of the addition amount. Therefore， it is recommended to add 1%SB220 to achieve a balance between mineralization loss and long-lasting sequestration.

Abstract:[Objective] The decoupling relationship between land-use carbon emissions and economic development， and the influencing factors were explored， in order to provide a theoretical basis for better aligning urban carbon reduction strategies with economic growth in the first batch of low-carbon pilot cities in China. [Methods] Taking the first batch of 8 low-carbon pilot cities （nemely Tianjin， Chongqing， Shenzhen， Xiamen， Hangzhou， Nanchang， Guiyang and Baoding cities） as the study area， the evolution trend of land-use carbon emissions in the pilot cities from 2005 to 2020 were analyzed. Based on the Tapio decoupling model， the decoupling relationship between land-use net carbon emissions and economic development was explored， and the influencing factors of net carbon emissions from land use were investigated by employing the logarithmic mean divisia index （LMDI） method. [Results] ① The net carbon emissions of the first batch of low-carbon pilot cities during 2005—2020 showed a rapid growth trend， increasing from 7.74×10⁸ tons in 2005 to 1.80×10⁹ tons in 2020. ② The overall decoupling index of the pilot cities gradually decreased during the study period， indicating that the dependence of economic development on land-use carbon emissions was on a downward trend. During the period from 2015 to 2020， the land-use carbon emissions of Tianjin City presented a desirable strong decoupling state from the economic development， while Baoding City showed an undesirable expansive negative decoupling state， and the remaining six cities showed a weak decoupling state. This reflected that there were still considerable potential for improvement in coordinating the relationship between land-use carbon emissions and economic development in the pilot cities. ③ Positive factors affecting land-use carbon emissions in descending order were： economic development level > land use structure > population density > total land area； negative factors were ranked as follows： economic efficiency of land use > carbon emission intensity of land type. [Conclusion] The decoupling status and the influencing factors of land-use carbon emissions in pilot cities varied significantly across regions， thus regionally differentiated low-carbon economic development strategies should be formulated in combination with the influencing factors.

Abstract:[Objective] A calculation method for horizontal ecological protection compensation standards within the Yangtze River basin was evaluated and established in order to provide a scientific basis for promoting the protection of water resources， restoration of the water ecological environment， and sustainable development of the economy and society within the basin. [Methods] Firstly， the value of ecosystem services provided by water resources in the Yangtze River basin during 2010—2020 were calculated using water surface area and a modified equivalent factor table. Secondly， the freshwater and water pollution ecological footprints and carrying capacities across the basin regions were estimated to evaluate water resource overload status. Finally， using the watershed-wide water resource ecological overload coefficient as a baseline， the identities of the compensation individuals and objects in each region were defined. Based on the theory of public goods attributes and externalities， the theoretical amount and lower-limit value of ecological protection compensation in each region were estimated by combining the water resource ecosystem service value. [Results] ① From 2010 to 2020， the value of ecosystem services from water resources in the Yangtze River basin increased annually to 1.17×10¹²，1.18×10¹²， 1.19×10¹² yuan. ② From 2010 and 2020， the freshwater ecological footprint of the Yangtze River basin first increased and then decreased， whereas the water pollution ecological footprint continued to increase. Based on the concept of ecological carrying capacity， the basin did not experience an overload during the study period. However， water supply-demand gaps were observed in regions such as Shanghai， Jiangsu City， and Henan Province. ③ During the study period， Qinghai， Xizang， Guangdong， Guangxi， Hunan， Jiangxi， and Fujian Province （autonomous regions） were consistent ecological protection compensation recipients， whereas Anhui， Yunnan， Zhejiang， Henan， Jiangsu Province， and Shanghai City were consistently compensation payers. The compensation amounts paid by the payer regions were within the scope of their general fiscal budgets and exhibited a year-on-year decline. [Conclusion] In the proposed calculation model， water ecology， water resources， and socio-economic development are closely integrated. It can provide a scientific and rational entry point and exemplar for water resource protection， water ecology maintenance， and the formulation of ecological compensation standards across the Yangtze River basin. It is expected to promote the continuous and in-depth development of ecological protection compensation work for first-level river basins in China.

Abstract:[Objective] The resource utilization efficiency and sustainability characteristics of agroforestry systems in hilly and gully loess areas were analyzed to optimize and promote agroforestry production models. [Methods] The theory and method of emergy analysis were used to systematically analyze the emergy input-output structure， environmental carrying effect， and sustainable development potential of four typical complex agroforestry models in Huanglong County， Yan’an City， Shaanxi Province， namely： walnut-purple perilla， walnut-maize， chinese pepper-potato， and Chinese pepper-red bean. [Results] ① All four modes were highly dependent on nonrenewable auxiliary energy （accounting for > 60%）， with fertilizers and mechanical power as the main inputs. The current production mode still relies on petrochemical energy support； The investment in renewable environmental resources accounts for over 24%， with rainwater potential energy and rainwater chemical energy being the main sources. This indicates that local water resources are relatively scarce and that planting relies heavily on natural rainfall. ② Among the four production modes， the contribution of local environmental resources was limited（emergy self-sufficiency ratio， ESR， 0.26~0.31）； The significant environmental pressure（environmental loading ratio， ELR， 1.78~2.35） and overall low net emergy yield ratio （EYR， 1.45~5.90） indicated that the production efficiency and ecological friendliness of the composite system in this region urgently need to be improved. ③ However， the Chinese pepper-red bean model showed outstanding performance， with EYR （5.90）， emergy sustainability index （ESI， 2.55）， and emergy per unit sustainability index （E/ESI， 0.67） were significantly higher than those of the other models and the average for Shaanxi Province. The analysis found that this advantage stems from the multiple ecological functions of red beans as leguminous plants with high solar energy conversion rate， nitrogen fixation efficiency， and resource synergy advantages. In contrast， the walnut-maize model displayed the worst energy utilization efficiency， owing to competition from tall crops. [Conclusion] In the loess hilly region and other similarly ecologically fragile areas， the auxiliary energy structure of agroforestry intercropping should be optimized， and the model of intercropping leguminous plants should be promoted.

Abstract:[Objective] The coupling coordination relationship， spatiotemporal characteristics and influencing factors between digital new quality productivity and water resource utilization efficiency were explored， in order to provide a scientific basis for promoting the synergistic development of the digital economy and high-efficience water resource utilization. [Methods] Using panel data of prefecture-level cities in Jiangxi Province from 2011 to 2022， the evaluation index system was constructed for digital new quality productivity and water resource utilization efficiency. The Super-SBM model， kernel density estimation， and geographical detector methods were employed to analyze the spatiotemporal characteristics of their coupling coordination degree and its driving factors. [Results] ① The level of digital new quality productivity in Jiangxi Province exhibited a year-by-year increasing trend， with significant disparities among the cities. Water resource utilization efficiency demonstrated a relatively stable “W”-shaped trend， namely， initially declining， then rising， declining again， and rising once more， resulting in an overall decline in efficiency. ② The coupling coordination degree showed a year-by-year increasing trend， with most cities transitioning from disorder to coordination. Spatially， it presented a distribution pattern characterized by large contiguous areas with small， scattered patches. The degree of coupling coordination is projected to increase in the future， with most cities expected to transition from primary to good coordination by 2027. ③ The primary driving factors of coupling coordination included effective agricultural irrigation area， topography， urbanization rate， and water resource endowment. The interaction effects between these factors manifested primarily as two-factor and nonlinear enhancements. [Conclusion] The level of coordinated development between digital new quality productivity and water resource utilization efficiency in Jiangxi Province was relatively low， with significant disparities among cities. Formulating regionally differentiated development strategies and optimizing policy support systems for multi-factor synergistic development is essential for achieving balanced progress in digital new quality productivity and water resource utilization.

Abstract:[Objective] The spatio-temporal differences， sources and evolution characteristics of the green transformation efficiency of resource-based cities in the Yellow River basin were analyzed， in order to provide references for promoting the integrated and coordinated advancement of the green transformation and high-quality economic developments in the region. [Methods] Based on statistical data from 37 resource-based cities during 2013 to 2022， a super-efficiency slack-based measure （SBM） model was selected to evaluate the level of green transformation efficiency， and the Dagum Gini coefficient was also used to analyze the different sources. The evolution characteristics of green transformation efficiency were revealed using the kernel density estimation method. [Results] ① The green transformation efficiency of resource-based cities in the Yellow River basin was steadily improved， showing the characteristics of ‘slight increase then rapid improvement’. ② The spatial heterogeneity of the green transformation efficiency of resource-based cities in different regions was obvious. The green transformation efficiency of downstream resource-based cities was higher than that of upstream and midstream cities. The regional differences were the main factor affecting the overall differences. ③ The gap in the efficiency of green transformation among resource-based cities in different regions was narrowed significantly； however， the difference in the efficiency of green transformation in the downstream cities was smaller than that of middle and upstream cities. [Conclusion] Resource-based cities in different regions of the Yellow River basin need to enhance regional cooperation， focusing on the radiation and driving effect of core cities with higher green transformation efficiency， formulating differentiated paths， to achieve the coordinated advancement of green transformation and high-quality development of resource-based cities and high-quality development in the Yellow River basin.

Abstract:[Objective] The level of coupled and coordinated development between intensive land use and ecological civilization construction were explored， in order to provide a scientific foundation for promoting sustainable urban development of cities in the Yellow River basin and guiding the formulation and implementation of relevant policies. [Methods] Fifty-seven cities in the Yellow River basin were selected as the study area and using data from 2011 to 2021. A comprehensive evaluation model was constructed to assess both intensive land use and ecological civilization construction. The coupled development of intensive land use and ecological civilization construction at the urban scale was analyzed using several methods， including the relative development degree model， coupled coordination degree model， kernel density estimation， spatial autocorrelation analysis， and spatiotemporal evolution dynamics. [Results] First， the overall level of urban land intensive use and ecological civilization construction in the Yellow River basin increased steadily from 2011 to 2021. However， there were significant regional disparities， and the overall intensive land use was still low. Second， except for some economically developed provincial capitals， the level of land-intensive utilization in most cities lagged behind that of ecological civilization construction. Only Jinan City and Taiyuan City achieved a state of synchronous development by 2021. The degree of coupling and coordination between intensive land use and ecological civilization construction in the Yellow River basin has generally increased， with most cities gradually shifting from a dysfunctional to a more coordinated state. This pattern is characterized by higher coordination levels in the eastern regions and lower levels in the western regions， along with notable spatial agglomeration effects. [Conclusion] To promote high-quality economic development across the Yellow River basin， cities should enhance the coordination between intensive land use and ecological civilization construction through strengthened regional linkages， tailored land use strategies， and the radiating influence of core cities.

Abstract:[Objective] Areas of ecological space conflict in the Hefei metropolitan area were identified， and collaborative strategies were proposed to provide references for regional ecological protection and economic development. [Methods] Ecological source areas and corridors were extracted using morphological spatial analysis and a minimum resistance model to construct an ecological security pattern. Coupling the suitability of supply and the scarcity of demand， the reasonable range of urban and agricultural spaces were evaluated， and key areas of non-ecological space were identified； The superposition analysis method was adopted to calculate the ecological space conflict index. [Results] ① Central and southern regions exhibited superior ecological connectivity， contrasting with severe fragmentation in northern areas. Ecological sources and corridors demonstrated distinct differentiation of more in the south and less in the north， with core sources aggregating in the southern hilly regions. ② Non-ecological spaces displayed concentric zonation： high development suitability and demand in the central zones， transitional characteristics in the suburbs， and lower values in peripheral areas. ③ Spatial conflicts manifested as heterogeneity of higher at the center， and lower alonge the edge with high and higher conflict zones （24.21% of the area） concentrated in urban-rural transition areas， reflecting ecological sensitivity and contradictions in development demand. Medium-low conflict zones （75.79%） occupied buffer regions with favorable ecological conditions and limited human disturbance. ④ In ecological space conflict zones， a dual governance mechanism featuring ‘ecological red lines enforcement’ and ‘adaptive non-ecological space management’ should be established， incorporating conditional access policies and dynamic adaptation strategies to reconcile ecological integrity with development needs. [Conclusion] The ecological space conflicts in metropolitan areas present a gradient differentiation feature of form core area to periphery. The coordinated allocation and differentiated governance of ecological and non-ecological spaces are the main paths for achieving ecological protection and high-quality development.

Abstract:[Objective] The spatial trade-offs of multifunctional cultivated land in mountainous and hilly regions of southwest China under the dual constraints of rapid urbanization and ecological conservation were analyzed， in order to provide scientific support for decision-making regarding sustainable land resource utilization and the alleviation of human-land conflicts. [Methods] Taking Chongqing City as the research area， a spatial function evaluation system was constructed for the three characteristics （production， life and ecology） of cultivated land. Methods such as the entropy weight method， comprehensive index evaluation method， coupling coordination degree model and K-means clustering analysis were adopted to explore the spatiotemporal evolution characteristics of multi-functionality and the coupled coordination relationship of cultivated land in Chongqing City from 2013 to 2022. [Results] ① The overall production function of cultivated land in Chongqing City showed the characteristics of lower in the east and higher in the west， larger concentration and smaller dispersion. This was mainly concentrated in the western part of Chongqing City on the periphery of the main urban area， while the ecological function formed high-value areas in the ecological corridors along the Wuling Mountains， Daba Mountains and the Yangtze River. ② The coupling and coordination degree of the three living space functions of cultivated land in Chongqing City significantly improved from 2013 to 2022， transforming from ‘low efficiency and imbalance’ to ‘initial coordination’. ③ Cultivated land in Chongqing City can be divided into an agricultural optimization transition zone （16.22%）， agricultural production vitality zone （40.54%）， and ecological life conservation zone （43.24%）. The utilization patterns of cultivated land in different functional zones showed clear spatial differentiation characteristics. [Conclusion] The multi-functionality of cultivated land in Chongqing City showed significant regional differentiation characteristics in temporal and spatial dimensions. Overall， it had transformed from ‘low efficiency and imbalance’ to ‘initial coordination’， but the imbalance in development among regions still exists. Greater attention should be attached on the multi-functional optimization of cultivated land in mountainous cities， regional territorial spatial planning， and the formulation of sustainable development policies.

Abstract:[Objective] The spatio-temporal evolution law of vegetation changes in the Lancang River basin was analyzed， in order to clarify the driving factors， and provide a scientific basis for the ecological protection and management of the basin. [Methods] The normalized difference vegetation index （NDVI） in conjunction with Theil-Sen trend analysis and the Mann-Kendall test were employed to systematically examine vegetation changes from 2000—2023. Furthermore， optimal parameter Geodetector was used to explore the combined effects of natural factors and human activities on spatial vegetation heterogeneity. [Results] During 2000—2023， the Lancang River basin exhibited a notable trend of vegetation improvement. In approximately 74.61% of the region， the NDVI values increased， with particularly marked recovery in low-altitude areas such as Yunnan Province. However， in northern and high-altitude regions of the basin， vegetation showed a declining trend， accounting for 25.39% of the area. The spatial distribution revealed a pattern of ‘higher in the south， lower in the north’. Elevation， land use type， and temperature were identified as the dominant factors influencing vegetation spatial variation， each explaining more than 50% of the variance. Moreover， the interaction among these factors exhibited greater explanatory power than any single factor， jointly shaping the vegetation distribution patterns across different areas of the basin. Additionally， the NDVI improvement trend significantly declined with increasing elevation， indicating that vegetation recovery and growth were severely constrained by climatic conditions at higher altitudes. [Conclusion] Strengthening ecological conservation and restoration efforts in high-altitude regions， along with implementing adaptive management strategies， will be essential for formulating more effective policies to mitigate the ecological impacts of climate change and human activities on the basin.

Abstract:[Objective] The water-production capacities of the first group of first five national parks in China were analyzed， and the key driving forces of each park were explored， in order to provide a scientific basis for optimizing the ecological protection and water-resource management of national parks. [Methods] Based on the InVEST model， the water-yielding capacities of each national park from 2000 to 2023 were assessed. The stability of the water-yielding capacities was analyzed in combination with the coefficient of variation（C_v）. The partial least squares path model （PLS-PM） was used to explore the functioning mechanism of the key driving force at each park quantitatively. [Results] ① From 2000 to 2023， the depths of the water-yields in the national parks generally demonstrated a fluctuating upward trend （excepte Hainan Tropical Rainforest National Park）. Wuyishan National Park had the largest water-yield depth （1 609.13 mm） and the largest increase （k=9.34）， while Sanjiangyuan National Park had the smallest water-yield depth （133.89 mm） and the most moderate increase （k=0.95）. ② The stability of the water yield of each park was as follows： Sanjiangyuan National Park > Hainan Tropical Rainforest National Park > Giant Panda National Park > Wuyishan National Park > Northeastern Tiger and Leopard National Park. ③ The key driving forces of the water yields of the parks differed significantly， demonstrating varying patterns of influence. Precipitation was the primary positive factor affecting water yield， and was significantly higher in Sanjiangyuan National Park （0.987 9） and Hainan Tropical Rainforest National Park （0.832 8） than in the other parks. Potential evapotranspiration was generally negatively correlated with the depth of water yield and was seen to be particularly significant at Giant Panda National Park （-0.458 1） and Wuyishan National Park （-0.348 5）. The impacts of vegetation cover and topography differed across the national parks. [Conclusion] From 2000 to 2023， the spatial and temporal patterns of water-yield capacities in the five first group national parks in China changed significantly and were relatively stable. The key driving forces of those patterns were shown to be different and spatially heterogeneous.

Abstract:[Objective] The response relationships of the net primary productivity loss （ΔNPP） of different vegetation types caused by drought of different vegetation types to various precipitation annual patterns were evaluated， in order to gain an in-depth understanding about the responses of vegetation to climate extreme events and provide a theoretical basis for regional drought prevention. [Methods] Drought characteristics was quantified by standardized precipitation evapotranspiration index （SPEI）， and NPP was estimated based on MODIS remote sensing data by carnegie-ames-stanford approach （CASA） model and annual SPEI during 2001 to 2020 in the middle arid zone of Ningxia Hui Autonomous Region was calculated to explore the differences of net primary productivity（NPP） of different vegetation types to SPEI， and the correlation between NPP loss （ΔNPP） due to drought and SPEI index by using the methods of trend analysis， Mann-Kendall test and correlation analysis. [Results] ① From 2001 to 2020， the SPEI index indicated that the drought trend in the study area was generally slowing down， and drought was still dominant in spatial dimension， but there was a trend of humidification. ② ΔNPP in the study area showed a totally decreasing trend of fluctuation； spatially， the ΔNPP in the eastern part of the study area decreased significantly. ③ The correlation analysis between SPEI index and ΔNPP showed that the negative correlation was dominant， but there were obvious spatial-temporal differences due to different drought grades. ④ The response of ΔNPP of different vegetation types to annual SPEI was different， under severe and extreme drought stresses， the NPP loss of forest was the largest， followed by crop， and shrubs was the least. [Conclusion] At present， the middle arid zone of Ningxia shows a trend of humidification. In order to improve the resistance of vegetation to drought in the study area， the complexity and diversity of vegetation structure and composition should be improved.

Abstract:[Objective] The impacts of landscape patterns on the water conservation capacity of small watersheds in the southern Jiangxi Province were explored to provide a scientific basis for optimizing these patterns and thereby managing water resources. [Methods] The water conservation capacity of 1 030 small watersheds in the study area was calculated using the InVEST model. Fragstats 4.3 software was used to obtain landscape pattern indices， such as forest cover ratio （FCR）， number of patches （NP）， edge density （ED）， mean patch area （AREA_MN）， landscape cumulative index （LCI）， contagion index （CONTAG）， and Shannon diversity index （SHDI）. Pearson correlation coefficients and the response surface analysis method were adopted to analyze how the landscape indices of small watersheds influenced their water conservation capacity. [Results] ① Among the landscape pattern indices， FCR， AREA_MN， and CONTAG showed highly significant positive correlations with water conservation capacity （p<0.001）， whereas LCI， NP， ED， and SHDI showed highly significant negative correlations （p<0.001）. ② According to the response surface of water conservation capacity to FCR and LCI， when LCI<0.218 and FCR>80.65%， water conservation capacity increased slowly with increasing FCR and decreasing LCI； when LCI>0.272 and FCR<58.82%， water conservation capacity increased significantly with increasing FCR and decreasing LCI. ③ In small watersheds with low net precipitation input （463—607 mm） and high terrain index （19—24）， and in those with moderate net precipitation input （607—751 mm） and low terrain index （12—19）， water conservation capacity showed only weak response to FCR and LCI. [Conclusion] By adjusting forest cover ratio and landscape cumulative index， the water conservation capacity of small watersheds can be improved. However， the improvement range is closely related to the terrain and precipitation conditions of small watersheds.