Abstract:[Objective] Soil aggregates serve as crucial indicators of soil fertility，with their stability directly governing the physical，chemical，and biological characteristics of soil. Under saline-alkali conditions，however， aggregates are adversely impacted by high salinity and strong alkalinity，leading to structural degradation and functional deterioration，which severely constrains agricultural productivity. This article aims to summarize the disparities in aggregates between saline-alkali and non-saline-alkali soil and elucidate the factors influencing aggregate formation and stability under saline-alkali conditions. [Methods] The study explored methods and strategies for improving the saline-alkali soil aggregate structure，and the implications of non-saline-alkali soil aggregate research for saline-alkali soil. [Results] Comprehensive analysis indicated that saline-alkali conditions undermined soil structure，diminished microbial diversity and activity，and ultimately led to a decrease in the quantity of macro-aggregates， an increase in the proportion of micro-aggregates， and weakened aggregate stability. In contrast，non-saline-alkali soil exhibited higher quantities of both macro-aggregates and micro-aggregates，a well-defined hierarchical distribution，rich biodiversity，and enhanced aggregate stability，mainly attributed to abundant organic matter content and more dynamic microbial activities. [Conclusion] To improve the aggregate structure of saline-alkali soil，an integrated approach combining hydraulic，physical，chemical，and biological measures is essential. This comprehensive strategy needs to focus on reducing soil salinity and alkalinity levels，regulating soil pH，improving soil structure，enhancing water retention capacity，and increasing nutrient availability. Future research should prioritize developing innovative techniques for aggregate structure assessment， optimizing soil amendment technologies，and integrating multi-scale data to facilitate progressive improvement of saline-alkali soil properties and support sustainable agriculture development.

Abstract:[Objective] Mycorrhiza，as a bridge connecting plants and soil，play a crucial role in soil carbon（C） budget. They absorb mineral nutrients from the soil in exchange for C fixed by plant photosynthesis，while simultaneously contributing to soil C loss through respiration. Although the roles of mycorrhiza in soil C input，C stability，and C sequestration are relatively well understood，knowledge of the effects of mycorrhiza on soil respiration remains less explored. [Methods] Using network exclusion and comparison methods，this review synthesizes current knowledge on the influence of mycorrhiza on soil respiration and its regulatory factors. [Results] Using the mesh exclusion method，researchers have successfully isolated and quantified mycorrhizal respiration，and found that it accounted for an average of 16.8% of soil respiration. Specifically，the contributions of arbuscular mycorrhizal respiration and ectomycorrhizal respiration to soil respiration are 18.4%（2.5%-32.0%） and 15.1%（3.0%-62.1%），respectively. Compared to mycorrhizal-free plants，mycorrhizal-inoculated plants increased soil respiration by an average of 26.0%. Mycorrhizal respiration responds differently to soil temperature and soil moisture across various ecosystems，with mycorrhizal respiration appearing to be more sensitive to changes in soil moisture. Soil nutrient availability regulates the symbiotic relationship between mycorrhizal fungi and plants by affecting the nutrient acquisition strategies of plants，thereby regulating mycorrhizal respiration. Additionally，biological factors such as fine root biomass，extraradical hyphal length density，and the substrates supplied by plants also have significant effects on mycorrhizal respiration. [Conclusion] As an important component of both soil respiration and autotrophic respiration，mycorrhizal respiration contributes substantially to soil C loss，which cannot be overlooked. More advanced methods are needed to isolate and quantify mycorrhizal respiration，and incorporate it into global C models to more accurately assess soil C cycling dynamics，thus providing a scientific basis for global C management and mitigating climate change.

Abstract:[Objective] This study aims to investigate the variation patterns of organic carbon storage in the plant-soil system following flooding restoration of degraded soda saline-alkali wetlands. [Methods] Typical long-term degraded marsh wetlands（alkali patches，Leymus chinensis grasslands）and Phragmites australis marshlands restored by flooding in the western Songnen Plain were selected as study sites. The aboveground and belowground vegetation biomass and physicochemical properties of the 1-meter soil profiles were measured to analyze the variation patterns of soil organic carbon（SOC）content and storage，along with their influencing factors，during the restoration of degraded saline-alkali wetlands. [Results] After restoration，the vegetation biomass and carbon pool of Phragmites australis marshlands reached 7 807.78 g/m² and 1.90 kg/m²，showing increases of 383.15% and 216.67%，respectively，compared with Leymus chinensis grasslands. The vegetation biomass and carbon pool of alkali patches were both zero. Flooding restoration promoted increases in both vegetation biomass and carbon storage. The SOC storage in the 1-meter soil profile of restored Phragmites australis marshlands reached 17.38 kg/m²，exceeding that of alkali patches and Leymus chinensis grasslands by 64.12% and 4.45%，respectively，with deeper layers exhibiting higher SOC than surface soils. Flooding restoration increased the SOC storage. SOC content and storage were significantly positively correlated with soil moisture（p<0.05），and negatively correlated with total nitrogen，total phosphorus，electrical conductivity，and the nitrogen-to-phosphorus ratio（p<0.05）. Significant differences in soil physicochemical properties were observed among alkali patches，Leymus chinensis grasslands， and Phragmites australis marshlands（p<0.05），and improvements in the soil environment during restoration facilitated SOC accumulation. [Conclusion] Flooding restoration of degraded soda saline-alkaline wetlands help enhance carbon sink capacity of the plant-soil system.

Abstract:[Objective] This study aimed to clarify the impacts of various planting patterns on rill morphological characteristics in sloping farmland within alpine canyon areas，and to select optimal planting patterns for enhancing soil and water conservation in the region. [Methods] Using bare slopes as control，we investigated four main planting configurations as the research subjects， including Zanthoxylum+Plum+Candian fleabane， Zanthoxylum+Cherry+Artemisia indica，Zanthoxylum+Green bean，and Plum+Soybean. The morphological characteristics of hillslope rills and their relationships with microtopographic alterations under different scour discharge rates（6，10，and 14 L/min）were analyzed through in-situ runoff plot scour tests combined with the Structure-from-Motion（SfM）photogrammetry. [Results] 1）Compared to bare slopes，the erosion area for various planting patterns ranged from 38.37% to 78.43%. Under high flow conditions（10 and 14 L/min），the fluctuation in slope roughness for different planting patterns was more pronounced compared to bare slopes （-16.49% to 11.56%）. After scour analysis revealed a 0.70% to 32.07% increase in 15° to 25° microtopographic units alongside a 1.40% to 51.48% reduction in 60° to 90° steep gradient segments. 2）Planting patterns altered the confluence patterns on slopes，resulting in a ″dendritic ″runoff network with fractal characteristics. At discharge rates of 6 and 14 L/min，the fractal dimension of the Zanthoxylum+Plum+Candian fleabane pattern ranged from 1.465 to 1.476，indicating superior flow redistribution capacity and effective regulation of hillslope sediment transport dynamics. The longitudinal profiles of rills under different planting patterns exhibited a ″wide and shallow ″morphology，with the width-to-depth ratio decreasing by 25.98% to 72.79% compared to bare slopes. 3）Compared to the micro-slope direction and micro-slope，the relationship between surface roughness and rill profile morphology was more closely associated（p<0.01）. Stepwise regression analysis revealed that surface roughness was the key factor driving rill development，and optimizing surface roughness could significantly reduce the risk of rill erosion. [Conclusion] The findings of this research can offer a theoretical foundation for rational allocation of soil and water conservation measures，as well as for effective prevention and control of soil and water loss in sloping farmland located in alpine canyon regions.

Abstract:[Objective] To investigate the effects of different straw incorporation methods on soil and water erosion and nitrogen and phosphorus losses in purple soil sloping farmland of southern Sichuan，and to select the optimal straw incorporation method for purple soil sloping farmland in the region. [Methods] Runoff plots were established on a typical purple soil sloping farmland（15°）in southern Sichuan. Five treatments were set up：no straw mulching （CK），low-amount straw mulching（T1：3 744 kg/hm²），high straw mulching（T2：7 488 kg/hm²），low-amount straw mulching+decomposition agent （T3： 3 744 kg/hm²+1.5 kg/hm²）， and high straw mulching+ decomposition agent（T4：7 488 kg/hm²+3 kg/hm²）. Monitoring included rainfall time，rainfall intensity， runoff，sediment characteristics，and nitrogen and phosphorus loss characteristics. The relationships between rainfall， runoff， sediment， and nitrogen and phosphorus losses were analyzed. [Results] 1） Among all treatments，T3 exhibited the best soil and water conservation effect. Compared with CK，it reduced runoff depth （by 40.2%）and sediment loss（by 55.3%）and effectively reduced nitrogen and phosphorus losses. 2）Correlation analysis showed that nitrogen and phosphorus losses were mainly controlled by runoff（p<0.01），but the concentration of total nitrogen （TN） in runoff increased over time， reducing the effectiveness of straw incorporation in controlling nitrogen loss. 3）The TN/TP ratio of runoff in all treatments was less than 22， indicating nitrogen limitation in the runoff of sloping farmland in the region. [Conclusion] Low-amount straw mulching combined with a straw decomposition agent can effectively improve soil and water conservation and nutrient utilization in the purple soil sloping farmland of southern Sichuan， providing a scientific basis for optimizing straw incorporation methods.

Abstract:[Objective] This study aims to objectively quantify the thickness of soil physical crusts，clarify the development process， and characterize the pore structure of physical crusts in Quaternary red clay （QRC）. [Methods] Artificial rainfall simulation experiments were conducted to obtain soil physical crust samples under varying rainfall durations. The crust thickness was quantified using X-ray computed tomography（CT）scanning and a soil porosity threshold method，serving as a key indicator for analyzing physical crust development and revealing the formation process of QRC crusts. Furthermore，the structural characteristics of crusted soil samples at different developmental stages were investigated by extracting two-dimensional（2D）and three-dimensional（3D）pore indicators. [Results] 1）The development of physical crusts in QRC exhibited four stages：the initial phase of particle dispersion and soil pore-filling，the second phase of soil compaction induced by raindrops，the third phase of stabilization，and the final phase of erosion. The average thickness of physical crusts in QRC measured at rainfall durations of 1，10，30，60，90，and 120 minutes was 7.75，8.07，10.83，11.53，11.49，and 6.35 mm，respectively. Except for the final measurement， crust thickness showed an initial increase followed by stabilization. The development process（1~90 min）was represented by a cubic polynomial equation：y=10.17－4.69x+2.49x²－0.30x³ （R²=0.882 3）. 2）The QRC physical crusts exhibited distinct 2D and 3D structural characteristics across different developmental stages. In the mid-development stage，2D parameters generally showed decreasing trends in pore number，porosity，and equivalent pore diameter，while circularity progressively increased. For 3D parameters，the fractal dimension initially expanded before stabilizing，whereas pore surface area and connectivity density first increased，then decreased. All measured parameters exhibited significant variations across different crust development stages. 3） The combined approach of X-ray CT scanning and porosity threshold analysis enabled objective quantification of physical crust thickness. The development process of physical crusts was clarified through analyzing thickness variations and pore structural characteristics. [Conclusion] The findings establish a scientific foundation for studying hydrological processes and enhancing erosion modeling accuracy in severely compacted regions.

Abstract:[Objective] The formation and development of niches in collapsing walls intensify the erosion of benggang and threaten land resources and the ecological environment. [Methods] The spatial distribution and morphological characteristics of niches in typical benggang erosion areas were investigated to explore their distribution patterns and evolutionary process. [Results] 1）Niches were mainly found in the lower part of collapsing walls，accounting for 45.83%，with 90.28% developed in the sandy layer，and the angles mainly ranged from 30° to 50°（50.69%）. 2）Niches showed strong variability in morphological parameters，with 90.97% of the niches having a flattening ratio greater than 0.1，primarily presenting as elliptical and extremely elliptical. 70.80% of the niches had both length-to-depth and short-to-depth ratios greater than 1，and 22.20% had a length-to-depth ratio greater than 1 and a short-to-depth ratio less than 1， reflecting that their plane morphology primarily extended vertically，and their evolutionary stage was influenced by horizontal expansion. 3）There was a highly significant positive correlation among the long axis，short axis and concavity depth of the niche（p<0.01），and the length-to-depth ratio and the short-to-depth ratio could indirectly influence each other and jointly drive the morphological development of the niche. [Conclusion] The study reveals the developmental characteristics and spatial distribution of niches in collapsing walls，providing a theoretical basis for the prevention and control of benggang erosion.

Abstract:[Objective] Physical clogging of riverbeds is a common problem in seasonal rivers，significantly affecting groundwater recharge and river ecological restoration. This study analyzes the infiltration and clogging characteristics of seasonal rivers，predicts the infiltration rates after riverbed disconnection，and provides scientific support for optimizing river ecological restoration and water replenishment schemes. [Methods] Taking the lower reaches of the Yongding River as a reference，five types of riverbed sediments with median particle sizes d₅₀ of 50， 100，150，300，and 600 μm were selected as experimental media. One-dimensional soil column infiltration simulation tests using 6 g/L muddy water were conducted to analyze the riverbed clogging characteristics and the transformation pattern from saturated to unsaturated flow. A prediction model for riverbed infiltration，considering the influence of physical clogging，was developed. [Results] 1）For fine particle riverbed with a median particle size of 50 μm，no significant clogging occurred. For riverbeds with particle sizes ranging from 100 to 600 μm， clogging occurred at a depth of 0 to 5 cm，and the hydraulic conductivity decreased by 86%，68%，93%，and 94%， respectively， compared to the initial values. 2） The 50 μm riverbed maintained saturated seepage throughout infiltration. For riverbeds with particle sizes ranging from 100 to 600 μm，the flow transformed from saturated to unsaturated seepage within 2.6 to 51.2 hours，with infiltration rates decreasing by approximately 15% to 30%. 3）A riverbed infiltration model considering clogging effects was constructed based on Darcy's law and the seepage formula for coarse particles. Model validation showed that the relative errors of the infiltration rates for four coarse-particle riverbeds（100-600 μm） were 8.6%， 14.7%， 22.1%， and 36.6%， respectively， and increased as the median particle size increased. [Conclusion] Fine sediment in muddy water has a significant impact on the clogging of coarse-textured riverbeds. The coarser the riverbed texture，the more likely it is to transform into a disconnected riverbed. A scientific understanding of the infiltration-clogging behavior of fine sediment in riverbeds of different textures is essential for optimizing ecological water replenishment schemes.

Abstract:[Objective] The study aims to explore the impact of future climate and land use changes on runoff prediction and its influencing mechanisms in a lake basin. It helps investigate hydrological response patterns， optimize water resource allocation，and formulate adaptive management strategies. [Methods] Taking the Erhai Lake Basin as the study area，the research integrated CMIP6 climate data and land use data，coupling the PLUS model and SWAT model to construct an analytical framework for runoff prediction under future climate and land use change scenarios. This framework predicted runoff in the Erhai Lake Basin under three climate scenarios based on Shared Socioeconomic Pathways（SSP1-1.9，SSP2-4.5，and SSP5-8.5），combined with future land use change. The geodetector with optimal parameter was used to reveal the main driving factors and their interactions affecting runoff in the basin. [Results] 1）Cultivated land，forest land，and grassland were the dominant land use types in the Erhai Lake Basin over the long term. From 2010 to 2020，urbanization drove the expansion of construction land，taking over cultivated land and forest land. By 2030，construction land was expected to reach 18 396 hm²，with an increase of 1 427 hm² mainly converted from cultivated land，reflecting the pressures of population growth and infrastructure demand. 2）The runoff in the Erhai Lake Basin in 2030 showed variations under the three scenarios. The highest runoff was observed under the SSP5-8.5 scenario（19.592 m³/s），followed by the SSP1-1.9 scenario（18.013 m³/s），and the lowest under the SSP2-4.5 scenario（17.387 m³/s）. Despite variations under different emission scenarios，the overall trend remained relatively stable. 3）The geodetector results indicated that wind speed exhibited strong independent explanatory power in most years，while the combination of precipitation and other factors showed significant interactive explanatory power. [Conclusion] In 2030，runoff in the Erhai Lake Basin remains relatively stable under all scenarios，with the annual average runoff following the trend of SSP5-8.5>SSP1-1.9>SSP2-4.5. In all three scenarios for 2030，wind speed has the greatest impact on runoff in the Erhai Lake Basin，while the combination of precipitation and other factors has a greater influence on runoff than other combinations.

Abstract:[Objective] To reveal the effects of different inflow patterns on slope erosion，sediment yield，and their hydrodynamic characteristics. [Methods] Based on simulated inflow scouring experiments，two inflow patterns （concentrated flow and sheet flow）and three flow rates（4，8，and 12 L/min）were designed to investigate the response mechanisms of slope erosion processes to inflow patterns. [Results] 1）Under concentrated flow and sheet flow，the slope runoff and sediment yield processes were basically consistent. The runoff yield process shifted abruptly and then stabilized，while the sediment yield process showed an initial rapid decline and then diminished with fluctuations. Compared with sheet flow，the soil erosion rate under concentrated flow exhibited stronger fluctuations，with coefficients of variation ranging from 71.49% to 111.94%. 2）The average flow velocity on the slope under concentrated flow was significantly higher than that under sheet flow（p<0.05），with differences ranging from 28.15% to 52.85%. 3）Under both concentrated flow and sheet flow，the slope flow types were consistent，both showing the coexistence of transitional flow and turbulent flow. However，significant differences existed in the slope flow regimes：concentrated flow showed supercritical flow，while sheet flow showed subcritical flow. 4）Under both inflow patterns，soil erosion rates were extremely significantly positively correlated（p<0.01）with Reynolds number，resistance coefficient，runoff shear stress，stream power，and runoff unit energy. However，the optimal hydrodynamic indicators differed：stream power（R²=0.68）for sheet flow and runoff shear stress（R²=0.80）for concentrated flow. 5）Compared with sheet flow，the slope soil erodibility indices（K_τ，K_ω，and Kε）under concentrated flow increased by 166.67%，81.25%，and 113.86%，respectively， and the corresponding critical hydrodynamic thresholds（τ₀，ω₀，ε₀）increased by 19.78%，40.70%，and 42.11%， respectively. [Conclusion] Concentrated flow shows stronger turbulence and higher erosion energy，leading to severe soil erosion. These findings help reveal the influencing mechanisms of inflow patterns on slope erosion processes and provide a crucial theoretical basis for developing slope erosion prediction models under different inflow patterns.

Abstract:[Objective] To reveal the physicochemical properties of soil aggregates at different particle sizes and their influence mechanisms on cadmium（Cd）speciation，this study investigates the distribution characteristics of aggregates in typical paddy soils and the effects of aggregates with different particle sizes on Cd environmental behavior. [Methods] Two types of Cd-contaminated paddy soils were selected，namely granitic sandy soil（developed from granite）and eel clayey soil（developed from shale and slate）. Soil aggregates were separated into four size fractions using the wet-sieving method： macroaggregates （2-8 mm） ， intermediate aggregates （0.25-2 mm） ， micro-aggregates（0.053-0.25 mm），and silt-clay particles（<0.053 mm）. The effects of removing organic matter and free iron oxides from aggregates of different sizes on Cd adsorption were analyzed. [Results] Both soils were dominated by macroaggregates. The eel clayey soil exhibited a more stable aggregate structure than the granitic sandy soil，with higher mean weight diameter（MWD）and geometric mean diameter（GMD）. The granitic sandy soil had a higher proportion of small particle size aggregates with a looser structure and lower stability，mainly due to the lower mass fractions of organic matter and free iron oxides in its parent material. As aggregate size decreased，the organic matter，free iron oxide，and cation exchange capacity（CEC）of aggregates significantly increased. The adsorption capacity of all aggregates for exogenous Cd was enhanced with decreasing aggregate size，with the silt-clay particles demonstrating the strongest adsorption capacity. After the removal of organic matter，the Cd adsorption capacity significantly decreased，while the decrease after the removal of free iron oxides was relatively small. [Conclusion] The differences in aggregate composition and structural stability caused by different soil types significantly influence their Cd adsorption and speciation. These findings provide a scientific basis for understanding the evolution of heavy metal pollution in paddy fields and formulating remediation strategies.

Abstract:[Objective] To investigate the effects of biochar combined with nitrification/urease inhibitors and straw mulching on nitrogen and phosphorus leaching under in situ field conditions，aiming to provide scientific evidence for controlling nitrogen and phosphorus leaching in tea plantations. [Methods] A red soil hillslope tea plantation in the subtropical region was selected as the study area. Five treatments were established：no fertilization（CK）， conventional fertilization（CON），biochar addition（BC），biochar combined with nitrification/urease inhibitors （BNI），and straw mulching（RS）. Over a one-year observation period，changes in soil physicochemical properties and leaching losses of nitrogen and phosphorus under natural rainfall conditions were monitored. [Results] During the observation period，compared to the CON treatment，the BNI treatment exhibited the highest soil ammonium nitrogen and nitrate nitrogen mass fractions，which were 2.8% and 72.8% higher，respectively. The higher ammonium nitrogen and nitrate nitrogen levels in the BNI treatment led to an increase of total nitrogen concentration in the leaching solution. Soil nitrogen and phosphorus leaching primarily occurred during the rainy spring and summer seasons. The BC treatment showed the highest leaching coefficient at 24.3%，while the RS treatment had the lowest at 8.3%. For total nitrogen loss in leaching solution，the BNI treatment（275.0 kg/hm²） was highest，and the RS treatment（65.9 kg/hm²） was the lowest. For total phosphorus loss，particulate phosphorus was the dominant form of loss，with the BC treatment yielding the highest loss（201.5 g/hm²）and the RS treatment the lowest（32.4 g/hm²）. Compared with the CON treatment，the RS treatment reduced total nitrogen loss in leaching solution by 43.6%，while the BNI and RS treatments decreased total phosphorus loss by 39.1% and 77.2%，respectively. [Conclusion] Considering both soil plant-available nutrient content and the effectiveness in controlling nitrogen and phosphorus leaching，straw mulching is an effective management practice for reducing nitrogen and phosphorus losses in tea plantations.

Abstract:[Objective] To elucidate the mitigation mechanisms of arbuscular mycorrhizal fungi（AMF）inoculation on soil nutrient and moisture supply deficiencies，thereby supporting the sustainable restoration of fragile karst ecosystems. [Methods] Based on an in-situ inoculation experiment in plantation plots of a typical karst rocky desertification area in Shaoyang County，Hunan Province，fine roots at 0-15 cm and 15-30 cm soil depths and soil samples at 0-15 cm，15-30 cm，and 30-50 cm soil depth were collected from upper，middle，and lower slopes. AMF infestation status，community composition，and soil physicochemical properties were measured to clarify the effects of key microbial additions on soil nutrients and moisture. [Results] The results showed that inoculation increased the infestation rate and intensity of root AMF. At the genus level，Paraglomus，Glomus， and Ambispora were the dominant genera in the AMF community，and their relative abundances changed significantly after inoculation，with differences across slope positions and soil layers. After inoculation，the Simpson's diversity index increased in the 0-15 cm layer at all slope positions，in the 15-30 cm layer at the mid-slope position，and in the 30-50 cm layer at the mid-lower slope position，but the differences were not significant. The Chao1 richness index increased across all layers，with a significant difference only at the upper slope position in the 0-15 cm layer. The Pielou's evenness index increased in the 0-15 cm layer at the mid-upper slope position，in the 15-30 cm layer at the mid-slope position，and in the 30-50 cm layer at all slope positions，but the differences were not significant. The mass fraction of alkali-hydrolyzable nitrogen（AN） decreased in all layers，the mass fraction of available phosphorus（AP）decreased only in the 15-30 cm layer， and the soil organic carbon mass fraction decreased in the 0-15 cm and 15-30 cm layers，but the differences were not significant. Soil volumetric water content（VWC）increased significantly in all soil layers，capillary porosity（CP）increased in the 0-15 cm and 30-50 cm layers，and pH and exchangeable Ca²⁺ decreased in all layers，but the differences were not significant. The AN：AP ratio showed a decreasing trend in the 0-15 cm and 15-30 cm layers，indicating that AMF inoculation could partially alleviate phosphorus limitation in the soil. Correlation and redundancy analysis indicated that changes in microbial community composition after inoculation directly or indirectly affected soil physicochemical traits including nutrients and moisture. [Conclusion] The results clarify the response characteristics of soil properties to AMF inoculation in karst rocky desertification plantation forests and identify nutrient and moisture changes and their driving factors，which helps overcome the bottleneck of delayed soil ecological function restoration and improves the service functions of fragile ecosystems.

Abstract:[Objective] Soil saturated hydraulic conductivity（K_s）is a critical parameter reflecting the transport capacity of water and solutes in soil，and is crucial for understanding and predicting processes such as soil water movement and soil erosion. Investigating the variation patterns and influencing factors of K_s under different vegetation restoration patterns in gully catchment areas of the Loess Plateau is of great significance for improving regional soil and water loss. [Methods] Thirty-eight typical vegetation restoration plots in the Zhifanggou small watershed（5 bare lands，3 drylands， 8 arbor forests，3 other forests，5 shrub forests，and 14 other grasslands）were selected as the research objects. The K_s， soil physicochemical properties，and root characteristics of the 0-10 cm soil layer in different plots were measured. Spearman correlation analysis，partial least squares regression（PLSR），and multiple stepwise regression analysis were used to reveal the influencing mechanisms of vegetation restoration patterns on K_s，and the K_s prediction model was established. [Results] Significant differences in K_s were observed under different vegetation restoration patterns（p<0.05）. The average K_s values were ranked as follows：shrub forests（1.46 mm/min）>other forests（1.36 mm/min）> other grasslands（1.23 mm/min）>arbor forests（1.04 mm/min）>drylands（0.65 mm/min）>bare lands（0.15 mm/min）. Spearman analysis and the PLSR model indicated that sand content，clay content，bulk density，maximum water-holding capacity，non-capillary porosity，root volume density，root mass density，root mass density in 1-2 mm diameter classes，and root mass density in 0-1 mm diameter classes were important influencing factors on K_s. Stepwise linear regression showed that after adding root indicators，the explanatory capacity of the prediction model was significantly improved，indicating that intermediate roots significantly optimized K_s by expanding the pore network and offsetting compaction effects. [Conclusion] Vegetation restoration markedly enhances K_s by improving pore structure through root-soil interactions. The research results provide a scientific basis for optimizing ecological restoration project configurations and hydrological model parameterization in the Loess Plateau.

Abstract:[Objective] Elucidating the effects of soil erosion-deposition on the soil quality of slope croplands in the black soil region of northeast China can provide an important scientific basis for the conservation and sustainable utilization of black soil resources. [Methods] Two slope croplands in the thick-layer black soil areas of Keshan County，Heilongjiang Province，were selected. The ¹³⁷Cs tracer technique was employed to estimate soil erosion rates. Based on the minimum data set（MDS）method，soil quality evaluation indicators were constructed to analyze the effects of soil erosion-deposition on soil quality in slope croplands of typical thick-layer black soil regions. [Results] 1）The soil erosion-deposition rates of slope cropland in the study area ranged from -1 563.2 to 7 916.1 t/（km²·a），with an average erosion rate of 2 669.0 t/（km²·a）. Moreover，in terms of spatial distribution， severe erosion occurred in the middle and lower parts of the slope，and mild-moderate erosion occurred at the slope top and in the middle and upper parts. Sediments were deposited in the 50 m section at the slope bottom，and the most severely eroded areas were located in the 120―170 m slope section. 2）MDS for soil quality evaluation was constructed，encompassing soil clay（Clay），soil organic carbon（SOC），total phosphorus（TP），available nitrogen（AN），microbial biomass carbon（MBC），and β -1，4-glucosidase（BG）. Moreover，the MDS could serve as a substitute for total data set（TDS）and more accurately reflect the soil quality status of croplands in the study area. 3）In the erosion zones of the study area，the soil quality index（SQI）was significantly negatively correlated with soil erosion rates（p<0.01）. In the deposition zones，the SQI showed an insignificantly positive correlation with deposition rates. In the two sample plots，the SQI in the erosion zones reduced by 13.3% on average compared to the deposition zones，and the spatial distribution of SQI showed an opposite trend to that of soil erosion rates. [Conclusion] Soil erosion is the key driving force for soil quality degradation of slope croplands in the study area.

Abstract:[Objective] This study aims to investigate the impacts of soil erosion-deposition processes on soil organic carbon（SOC）fractions and their interaction mechanisms，to enhance understanding of carbon stock management strategies and SOC response mechanisms in the cultivated black soil region of northeast China. [Methods] The research focused on typical sloping cultivated land in Bin County（thin-layer black soil）and Keshan County（thick-layer black soil）. The ¹³⁷Cs tracing technique was employed to quantitatively assess soil erosion intensity，identify differences and trends in slope SOC fractions under different erosion intensities，and elucidate the mechanisms by which soil erosion affects SOC fractions. [Results] The annual average soil erosion modulus was 2 822.99 t/（km²·a）in the thin-layer black soil area and 2 174.74 t/（km²·a）in the thick-layer black soil area. Soil erosion-deposition rates were found to be the primary drivers of changes in SOC fractions. SOC fractions decreased significantly with increasing soil erosion rates， exhibiting a significant negative correlation. The loss rates of different SOC fractions were ranked as follows：EOC > POC > MBC > DOC. [Conclusion] Total nitrogen（TN）is identified as a key factor influencing the distribution of SOC and its fractions，while the C/N ratio，clay content，and sand content also have significant effects on the distribution of SOC fractions.

Abstract:[Objective] This study aims to investigate the variation characteristics of soil organic carbon（SOC） fractions and their stability in arid valleys，clarify the relationships between environmental factors and SOC fractions as well as stability，and provide a scientific basis for systematic carbon sequestration and emission reduction management in ecologically fragile areas. [Methods] Soil samples（0―30 cm depth）were collected from different slope aspects（shady，sunny，semi-shady，and semi-sunny slopes）and slope positions（lower， middle，and upper）in the arid valleys of Bomi，Xizang. Soil physicochemical properties，SOC contents，and its fractions were measured. [Results] 1）The SOC content on shady slopes ranged from 11.37 to 34.74 g/kg， representing increases of 55%，138%，and 292% compared with semi-shady，semi-sunny，and sunny slopes， respectively. The contents of particulate organic carbon（POC），easily oxidizable organic carbon（EOC），mineral-associated organic carbon（MAOC），and dissolved organic carbon（DOC）all exhibited consistent variation trends with SOC across different slope aspects. SOC stability was the highest on shady slopes（54.3%-62.1%），exceeding that of semi-shady，semi-sunny，and sunny slopes by 6%，12%，and 30%，respectively. 2）Along slope positions， SOC content decreased in the order was lower slope（17.29 g/kg）>middle slope（13.42 g/kg）>upper slope （9.73 g/kg）. Similarly，POC，EOC，MAOC，and DOC contents all decreased with increasing slope position. The stability of SOC across different slope positions followed the pattern was lower slope（38.1%-62.1%）>middle slope （36.9%-59.9%）>upper slope（37.6%-58.7%）. 3）The main environmental factors influencing SOC fractions and their stability in the arid valleys of southeastern Xizang were slope aspect，vegetation coverage，soil total nitrogen （TN），alkali-hydrolyzable nitrogen（AN），total phosphorus（TP），and clay content. [Conclusion] Significant differences exist in SOC fractions and their stability across different slope aspects and positions in the arid valleys of southeastern Xizang. The key regulatory factors include slope aspect，vegetation coverage，total nitrogen， alkali-hydrolyzable nitrogen，total phosphorus，and clay content. These findings provide valuable references for accurate SOC assessment and soil carbon pool management in arid valleys of southeastern Xizang.

Abstract:[Objective] Compared with naturally formed tropical coral islands，newly formed coral islands develop dense layers within their profiles due to hydraulic filling and sedimentation during the construction process. This study aims to investigate the effects of the hydrological properties and hydrological conditions of coral sand profile structures on hydrological processes such as slope water drainage，subsurface runoff，and coral sand particle transport. [Methods] Taking the dense layers in the profile of a newly formed coral island as the research object， in-situ profile surveys and sampling were conducted to analyze the texture types and hydro-physical properties of the coral sand profile. Combined with laboratory-simulated rainfall experiments，the hydrological process and coral sand loss characteristics on slopes with homogeneous layers and dense layers under different hydrological conditions were analyzed. [Results] Coarse coral sand exhibited strong hydraulic conductivity，while the dense layer had poor hydraulic conductivity，with a saturated hydraulic conductivity only 8% of that of other coral sand texture types. On slopes with homogeneous coral sand，all rainfall infiltrated through leaching，with no surface runoff. In contrast，the dense layer retarded water migration to deeper layers，causing subsurface runoff as the main form，accounting for about 87% of total rainfall and leading to particle transport and loss within the coral sand body. At the same time，changes in hydrological conditions，from free drainage to saturation and seepage， could promote subsurface runoff and coral sand loss，but a dense layer with low hydraulic conductivity could reduce coral sand loss under seepage conditions. [Conclusion] Dense layers can significantly alter the freshwater hydrology and sand particle loss of coral sand， potentially leading to effects such as shallower freshwater circulation and the development of dissolution fissures in localized areas. These results are of great significance for understanding the circulation process of coral islands and for the construction of ecological islands.

Abstract:[Objective] To establish a constitutive model applicable to different growth stages of vetiver grass root-soil composite，in order to precisely simulate and predict its mechanical behavior. [Methods] Three groups of vetiver-laterite composite samples at different growth stages（20 days，40 days，and 60 days）were selected as the research subjects. Mechanical parameters were obtained through triaxial tests. Based on the mixture rule，the constitutive relationships of soil and plant roots were calculated using the Duncan-Chang model and the linear elastic model，respectively，and then superimposed based on volume fraction. [Results] 1）The two-phase superimposed constitutive model based on the mixture rule demonstrated excellent performance in simulating the mechanical behavior of the root-soil composite（R² >0.89）. The stress-strain curves of this model accurately reflected the changes in the shear strength and stress-strain relationship of the root-soil composite in the triaxial tests at different growth stages. 2）Using the Duncan-Chang model and the linear elastic model as the constitutive relationships for the primary and reinforcement phase，respectively，the characteristics of the stress-strain response of the two materials during shear could be effectively simulated and accurately reflected. 3）The vetiver grass roots effectively reinforced the soil. During the growth cycle，with the extension of time，the number，diameter，and volume of the roots gradually increased，while the elastic modulus gradually decreased. The reinforcement effect of the roots progressively enhanced，leading to a gradual increase in the shear strength of the root-soil composite structure. [Conclusion] The proposed model not only comprehensively describes the stress-strain relationship of the root-soil composite but also accurately evaluates the soil reinforcement effect of plant roots at different growth stages through parameters such as root quantity，single-root elastic modulus，and root volume. The results provide a scientific basis for slope stability analysis and the application and planning of ecological slope protection technologies.

Abstract:[Objective] To reveal the effect of nitrogen（N）and phosphorus（P）additions on soil aggregate carbon in subtropical evergreen broad-leaved forests. Understanding these effects is crucial for comprehending the stability of soil organic carbon（SOC）and the carbon cycle within these ecosystems. [Methods] A series of N and P addition test platforms were established in an evergreen broad-leaved forest for a duration of six years，including control， 100 kg/（hm²·a）of N，50 kg/（hm²·a）of P，and a combination of 100 kg/（hm²·a）of N plus 50 kg/（hm²·a）of P. The response of soil organic carbon across different particle sizes to nitrogen deposition and phosphorus addition was assessed through particle size grading analysis，phosphorus component analysis，and evaluation of the molecular structures of organic carbon. [Results] The addition of nitrogen significantly increased the SOC mass fraction in macro-aggregates（>2 mm）as well as in clay and silt particles（<0.053 mm）. It also significantly reduced the degree of soil organic carbon decomposition（SD）in both macro-aggregates（>2 mm）and small aggregates（0.25~2 mm）. The combined application of nitrogen and phosphorus（N+P）led to a significant increase in the mass fraction of polysaccharides，alcohols，and phenols in macro-aggregates（>2 mm）. Additionally， it significantly decreased the SD in small aggregates（0.25~2 mm）and increased the mass fraction of resin（Resin-P） in labile phosphorus across various particle sizes，except in micro-aggregates（0.25~0.053 mm）. Redundancy analysis indicated that NaOHs-Pi and residual phosphorus were the principal drivers influencing the molecular structure of aggregates larger than and smaller than 2 mm， respectively. [Conclusion] Nitrogen deposition enhances the accumulation of recalcitrant phosphorus，thereby improving the chemical stability of soil organic carbon.

Abstract:[Objective] This study aims to investigate the spatiotemporal variations and trade-off/synergistic relationships of ecosystem services along altitudinal gradients in the Yarlung Tsangpo River basin，coordinate regional economic development and ecological conservation， and promote regional sustainable development. [Methods] The InVEST model was applied to evaluate the spatiotemporal variations of five critical ecosystem services（habitat quality，water yield，soil retention，carbon sequestration，and food supply）in the basin from 2000 to 2020，with quantitative analysis across different altitudinal gradients. Spearman correlation analysis and Geographically weighted regression were also used to reveal the changes in the trade-off/synergistic relationships among ecosystem services. [Results] 1）From 2000 to 2020，high-value areas of ecosystem service supply are mainly distributed in the lower reaches of the Yarlung Zangbo River basin. Habitat quality maintained consistently high levels，averaging approximately 0.8，accompanied by a significant increase in carbon sequestration. Notably， soil retention capacity demonstrated a substantial increase of 12.43%，while water yield experienced a marginal decline of 1.26%，due to reduced precipitation. 2）Habitat quality，soil retention，and carbon storage exhibited significant increases（p<0.05），with substantial changes observed across 30.24%，42.58%，and 65.40% of the watershed area，respectively. All ecosystem service values declined with increasing elevation，demonstrating distinct altitudinal thresholds：>4 800 m for habitat quality，>3 800 m for water yield，>3 800 m for soil retention，and >2 800 m for carbon storage. 3）Quantitative analysis revealed that food supply showed a weakly increasing synergistic trend with water yield，while soil retention showed a similar trend with habitat quality. The most pronounced synergy was observed between water yield and soil retention（approximately 0.83），while other synergies averaged 0.56. Notably，a significant trade-off relationship was identified between food supply and habitat quality. Spatial analysis demonstrated that synergistic areas between carbon storage and habitat quality constituted the largest proportion of the study area（31.12%，p<0.05）. [Conclusion] The results elucidate the ecosystem service supply capacity across the Yarlung Tsangpo River basin，its altitudinal variation patterns，and the quantitative and spatial trade-offs/synergies among ecosystem services. This research provides a scientific foundation for ecological conservation and restoration.

Abstract:[Objective] With global warming exerting persistent impacts on the climate system， this study investigates the evolving trends and spatial patterns of climatic elements across China under different warming scenarios，aiming to provide a scientific foundation for formulating differentiated climate adaptation strategies. [Methods] High-resolution data from the NASA Earth Exchange Global Daily Downscaled Projections（NEX-GDDP-CMIP6）were utilized to assess changes in climatic elements across China under global warming scenarios ranging from 1.5 ℃ to 5.0 ℃. Emphasis was placed on analyzing trends and spatial distribution of six key climate variables. [Results] The rate of land surface warming in China exceeded the global average，and the magnitude of temperature rise showed an intensifying trend relative to global temperature increases. When the global temperature rose by 1.5 ℃，China's annual mean temperature increased by approximately 1.3 ℃，whereas under a 5.0 ℃ global warming scenario，this rise reached 5.92 ℃. The minimum temperatures increased even more markedly，reaching 6.21 ℃，with significant warming observed in northeast China，north China，and the Qinghai-Xizang Plateau. Precipitation increased significantly with rising temperatures. Under a 3.0 ℃ global warming scenario，70% of regions experienced annual precipitation increases by over 50 mm，with increases exceeding 100 mm in the Qinghai-Xizang Plateau and northwest China. With warming，the frequency and intensity of extreme high-temperature and precipitation events might intensify. Wind speed and relative humidity show declining trends， potentially affecting wind energy utilization and the regional water vapor cycle. Under a 1.5 ℃ warming scenario， wind speed decreased by about 0.15 m/s，declining to 0.32 m/s under a 5.0 ℃ warming scenario，which was double the decrease in the 1.5 ℃ scenario. Relative humidity declined by 0.34% compared to the reference period when the global temperature rose by 5.0 ℃，but substantial inter-model uncertainties persisted. [Conclusion] These findings provide a scientific basis for climate adaptation and mitigation policies in China，underscoring the critical need to constrain global temperature rise to address potential climate challenges and reduce future climate risks.

Abstract:[Objective] Variations in meteorological conditions，vegetation characteristics，soil properties，and topographic features lead to differences in soil moisture distribution along hillslopes，which in turn cause significant spatial variability in soil water storage（SWS）. However，the current understanding of soil moisture dynamics and their influencing factors at different slope positions on forested hillslopes remains insufficiently systematic. [Methods] A study was conducted on a typical larch forest hillslope in the semi-humid Liupan Mountains. From May to October 2023，the spatiotemporal variations in soil volumetric water content were monitored at three slope positions（upper，middle，and lower）within the 0―80 cm soil layer. During the same period，meteorological conditions，vegetation structure，and soil physical properties were observed simultaneously. [Results] 1）Soil water storage（SWS）varied significantly across different slope positions，with the average values following the order：middle slope>lower slope>upper slope. However，the greatest fluctuations in SWS were recorded on the middle slope. 2）Temporally，the incremental changes in SWS within the 0―80 cm soil layer exhibited strong variability across all three slope positions during a single rainfall event. Among different layers，the SWS in the 0―10 cm and 10―20 cm soil layers demonstrated relatively lower variability. The primary factors influencing the temporal variation of SWS increments were rainfall amount and duration. The variation in SWS reduction in the 0―80 cm soil layer was also highly variable at all three slope positions during a single rain-free period，with the least variability observed in the 10―20 cm soil layers. The main factors affecting the temporal variation of SWS reduction were potential evapotranspiration and the duration of rain-free periods. 3）Spatially，SWS increment magnitude followed the order of middle slope>lower slope>upper slope，mainly related to soil bulk density and saturated hydraulic conductivity. The magnitude of SWS reduction followed the order of middle slope>upper slope>lower slope，mainly related to stand evapotranspiration，gravel volumetric content，and total porosity. [Conclusion] These findings provide valuable insights into the mechanisms of soil water redistribution on forested hillslopes and offer scientific guidance for sustainable forest-water management in semi-humid mountainous regions.

Abstract:[Objective] This study aims to assess the forest ecosystem service value in Fujian Province，providing valuable insights for ecological conservation and high-quality development in the region. [Methods] From a spatiotemporal geographical perspective， this study evaluated the forest ecosystem service value of Fujian Province for the years 2000，2003，2008，2013，2018，and 2023 using the value equivalent method with three rounds of coefficient adjustments. ArcGIS tools，including the center of gravity model and spatial analysis，were employed to examine the spatiotemporal evolution patterns. [Results] 1）Fujian's forest ecosystem exhibited extensive coverage，with total area increasing first and then declining，showing a relatively balanced distribution. However，the forest ecosystem became increasingly dispersed，with more pronounced fragmentation. 2）The forest ecosystem service value exhibited a fluctuating trend with a slight overall decline and limited variation. Regulation services were the dominant component，and their trend closely mirrored the overall service value trend. Forest ecosystem service value grades showed clear spatial and regional distribution patterns across different stages，with varying forest ecosystem service value classifications among counties. 3）Spatially，forest ecosystem service value displayed a "northeast-southwest" distribution， with the center shifting southwestward， gradually deviating from Fujian′s geometric center. The coverage of the standard deviation ellipse remained relatively stable， indicating enhanced spatial equilibrium. 4）The forest ecosystem service value in Fujian Province exhibited spatial distribution of high-high and low-low clustering，with these types of clusters being significant，while the low-high and high-low clustering effects were not obvious. [Conclusion] The results are of practical significance for identifying the full inventory of forest ecosystems and optimizing spatial allocation，thus supporting the formulation of science-based ecological protection and management policies in Fujian Province to foster sustainable regional development.

Abstract:[Objective] Meadow soils on the Qinghai-Xizang Plateau are highly sensitive to changes in the frequency of seasonal freeze-thaw cycles caused by climate change，and it is therefore urgent to understand how microbial activity in these soils responds to different numbers of freeze-thaw cycles. [Methods] Typical alpine meadow soil from a region of the Qinghai-Xizang Plateau with frequent seasonal freeze-thaw activity was selected as the study subject. Simulations with 1，3，5，7，and 9 freeze-thaw（FT）cycles（termed C1，C3，C5，C7，and C9）and a non-freeze-thaw control（N9）were conducted to compare the response characteristics of typical soil parameters：dissolved organic carbon（DOC），microbial biomass carbon and nitrogen，and gaseous carbon and nitrogen. [Results] 1）Compared with the non-FT treatment（N9），soil microbial biomass carbon（SMBC） decreased significantly by 23.64% after C9，while DOC increased significantly by 7.37%，and the cumulative emissions of CO₂ and N₂O increased by 71.09% and 321.40%，respectively. 2）With increasing FT cycles，DOC content and activities such as β -glucosidase and leucine aminopeptidase showed a nonlinear trend：they first declined and reached minimum levels at C5. The CO₂ emissions rates peaked after the first two freeze-thaw cycles （1.83 times that of the non-FT soil），while N₂O emission rates sharply increased after the fifth cycle，reaching 5.83 to 24.82 times that of the non-FT soil. 3） Soil microbial biomass nitrogen （SMBN） did not vary significantly，but the concentrations of NO₃^--N and the activity of N-acetylglucosaminidase（NAG）increased steadily，while NH₄⁺-N decreased steadily，as the number of FT cycles increased. [Conclusion] The effects of multiple freeze-thaw cycles on soil microorganisms are not merely repetitions of a single freeze-thaw event. After five cycles，changes in pore structure and microbial mortality caused by soil water freezing and swelling have largely stabilized，and the surviving microbial communities gradually adapt to the new temperature conditions， restoring their activity during subsequent cycles. These findings could provide new theoretical insights and data for understanding the overwintering mechanisms of microorganisms in alpine meadow soils affected by seasonal freeze-thaw cycles.

Abstract:[Objective] To investigate the spatiotemporal evolution characteristics of forest ecosystem health in the mountainous areas of Beijing during 2005—2020，with particular emphasis on analyzing regional variations and the explanatory power of the influencing factors. [Methods] A forest ecosystem health evaluation system was established based on four criteria layers，including geographic environment，vegetation structure，ecological pressure，and vegetation function. The entropy-weight TOPSIS method was applied to calculate indicator weights and evaluate the health of forest ecosystems in the mountainous areas of Beijing. Temporal variations in ecosystem health characteristics were analyzed for the years 2005，2010，2015，and 2020. On this basis， spatial autocorrelation analysis and K-means clustering analysis were employed to investigate the spatial clustering patterns and regional variations in ecosystem health. Furthermore，the single-factor and interactive detection modules of the geographical detector model were utilized to quantitatively assess the explanatory power of various indicator factors influencing the spatial distribution of forest ecosystem health. [Results] 1）From 2005 to 2020，the health condition of forest ecosystems in the mountainous areas of Beijing exhibited a consistent upward trend. At this stage， these forest ecosystems were predominantly moderately healthy（41%） or relatively healthy（48%），forming a spatial differentiation pattern characterized by higher health levels in farther urban areas and lower health levels near the urban zones. 2）The forest ecosystem health in the mountainous areas of Beijing showed continuous improvement，with particularly notable progress between 2015 and 2020，as the proportion of areas classified as ″excellent health ″increased from 2.43% to 18.65%. The Moran's index in the study area exhibited a decline-then-rising trend from 2005 to 2020，indicating significant global and local spatial autocorrelation with clustering patterns. Among the significant spatial types， positive correlations dominated，with HH（41.8%）and LL（30.8%）clusters collectively accounting for 79.6% of all significant spatial types. 3） The spatial heterogeneity of forest ecosystem health in the mountainous areas of Beijing were analyzed at the township level. The results demonstrated that regions such as Huairou，Miyun，and Yanqing exhibited relatively higher ecological health levels，while forest ecosystems in Fengtai， Haidian， and Shijingshan districts showed comparatively poorer health conditions. 4） Soil conservation，Leaf Area Index（LAI），Normalized Difference Vegetation Index（NDVI），tree cover，and population density were identified as the dominant factors influencing forest ecosystem health in the mountainous areas of Beijing. The interactive effects among the factors showed nonlinear enhancement and two-factor enhancement patterns. The primary driving factors of forest ecosystem health in the mountainous areas of Beijing showed distinct variations：GDP and soil conservation were the dominant factors in 2005， followed by LAI and soil conservation during 2010—2015，while air purification and soil conservation were dominant in 2020. [Conclusion] Based on the analysis，the health condition of forest ecosystem in the mountainous areas of Beijing show consistent improvement during the 2005—2020 period，with the role of ecological services becoming increasingly prominent in shaping overall forest ecosystem health. These findings suggest that future forest management and conservation strategies should prioritize the enhancement and maintenance of forest ecosystem service functions.

Abstract:[Objective] To explore the interactive coordination effect between urban green land use efficiency and high-quality urban development，and to provide scientific insights for facilitating the green transition in urban land utilization and advancing regional high-quality development. [Methods] Taking 41 prefecture-level cities in the Yangtze River Delta region as research subjects，this study constructed an evaluation index system. Then，urban green land use efficiency and high-quality development index during 2008—2022 were assessed，employing the Super-EBM with undesirable outputs and the entropy-TOPSIS model， respectively. A panel vector autoregression （PVAR） model was also adopted to reveal their interactive relationships. Furthermore， an improved coupling coordination model and GM（1，1）gray prediction model were applied to investigate their spatiotemporal coordination characteristics and future evolution trends. [Results] 1）The urban green land use efficiency in the Yangtze River Delta region demonstrated a fluctuating upward trend，exhibiting spatial patterns characterized by ″westward retreat with eastward advancement and progressive homogenization ″. Meanwhile， high-quality development displayed pronounced non-linear growth trends，forming a prominent spatial pattern marked by ″core-periphery radiation with axial extension ″. 2）The analysis revealed a bidirectional causal relationship between urban green land use efficiency and high-quality development index. Both of them experienced bidirectional shocks（endogenous and cross-systemic），but were driven predominantly by endogenous structural factors，thus demonstrating inertial dependence characteristics. High-quality development exerted a stronger promoting effect on urban green land use efficiency. 3）The coupling coordination between the two systems showed consistent growth，exhibiting a clear regional hierarchy：Shanghai > Jiangsu > Zhejiang > Anhui. Spatially，it manifested characteristics as follows：southern regions outperformed their northern counterparts， coastal areas demonstrated superior coordination to inland zones， while central cities exhibited significant developmental uplift. A ″Z-shaped ″axis pattern centered on developed cities emerged clearly. The coordination was expected to continuously improve， but the core-periphery distribution situation would be consolidated. [Conclusion] By fully implementing the requirements of high-quality development，leveraging the spillover effect of core growth，and implementing targeted policies for different types of cities，overall interactive and coordinated regional development can be achieved.

Abstract:[Objective] This study aims to investigate the construction of the water ecological security pattern in ecological protection，restoration，and sustainable development of river basins. [Methods] Taking the Liao River main stream basin as a case study，three water ecological services with hydrological transmission characteristics， namely water yield，water purification，and soil conservation，were selected. Based on the ″source-flow-sink ″ conceptual framework，the InVEST model was employed to quantitatively assess the supply-demand relationship of water ecosystem services to identify the ″sources ″and ″sinks ″. The circuit theory was utilized to identify ecological corridors，ecological pinch points，and barriers mediated by water flow. Ultimately，the water ecological security pattern of the river basin was constructed. [Results] The total area identified for the three water ecosystem services is 12 200 km² for the ″source ″and 4 900 km² for the ″sink ″；there are 287 tree-like and network-like ″ flows ″，primarily extending from the main river to the tributaries；there are 79 ecological pinch points and 111 ecological barrier points. [Conclusion] The research findings provide a basis and strategies for zoning and classification，identification of key areas，and layout of restoration projects in river basin ecological restoration.

Abstract:[Objective] Land use is an important pathway through which human activities impact climate change. Exploring the mechanisms and effects of land use changes on regional climate is a key scientific issue for regulating global sustainable development. [Methods] Based on the RegCM 4.7 regional climate model with an output resolution of 50 km，the evolution of regional climate in China under land use changes from 2009 to 2018 was simulated，and the mechanisms of temperature and precipitation changes were explored from the perspectives of surface heat balance and low-level circulation field. [Results] 1）Land use changes had a more significant effect on temperature in the study area. 2）Different types of land use changes had different climatic effects：converting agricultural land to forest land led to an increase in summer temperature and precipitation，converting forest land to agricultural land decreased temperature， and converting agricultural land to construction land resulted in increased temperature but reduced precipitation. 3）The effects of land use changes on climate exhibited significant spatial heterogeneity（stronger response in the east than in the west）and seasonal differences，with stronger responses in summer temperature and precipitation. 4）Different land use type conversions regulated temperature and precipitation through different mechanisms. The conversion of agricultural land to construction land in East China increased summer temperature by 0.14 ℃ ，while forest expansion in South China increased precipitation. [Conclusion] The study verifies the applicability of the RegCM 4.7 model. The results offer a scientific basis for developing climate-resilient land spatial planning strategies.

Abstract:[Objective] To explore the future development of production-living-ecological space and evaluate the future habitat quality in Hunan Province，considering both economic and ecological development，which plays an important role in the allocation of land spatial resources and ecological security management. [Methods] Based on the land use data from 1990 to 2020，land use transfer matrix and dynamic degree analysis were used to analyze the composition of the production-living-ecological space in Hunan Province in the past 30 years. The multi-object planning model was used to build different development scenarios，and the PLUS and InVEST models were employed to predict and analyze land use changes under these scenarios. [Results] 1）From 1990 to 2020， ecological space accounted for the largest proportion in Hunan Province，approximately 69.44%，followed by production space at about 28.74%，and the smallest proportion was living space. Frequent conversion occurred between production and ecological spaces，while the living space conversion，although smaller in area，had the largest variation. 2）All four scenarios showed a trend of a reduction in production and ecological spaces，and an increase in living space. In the scenario prioritizing the development of production and living spaces，the growth of living space was the fastest，with the greatest economic benefit，reaching 1.23 times that of 2020. In the scenarios prioritizing ecological development and natural development，the reduction of ecological space was smaller，with the ecological benefits decreasing by 0.098% and 0.150%，respectively，compared to 2020，but the economic benefits were lower. The balanced and coordinated development scenario of the production-living-ecological space protected ecological space while meeting regional development needs，balancing ecological and economic benefits. 3）From 1990 to 2020，the proportion of high-quality habitats in Hunan Province was the largest，with relatively good overall habitat quality，showing little fluctuation but with a downward trend. The simulation predicted a slight decline in habitat quality by 2030. [Conclusion] The habitat quality change in Hunan Province by 2030 is expected to be minor. The balanced and coordinated development of the production-living-ecological space，which considers both economic and ecological benefits，is most suitable for the future development of the region.

Abstract:[Objective] To explore the imbalance in the supply and demand of ecosystem services in Anhui Province and provide a reliable basis for regional ecological security pattern construction under the dual drive of global climate change and the intensifying socio-economic activities. [Methods] Anhui Province was selected as the study area. By integrating the InVEST model with the hotspot analysis method，the supply and demand of four key ecosystem services，i.e.，water yield，habitat quality，carbon storage，and soil conservation，in Anhui Province from 2003 to 2023 were systematically evaluated，along with the distribution patterns of comprehensive cold and hot spots. Circuit theory was employed to construct the ecological supply and demand pattern. [Results] 1）From 2003 to 2023，water yield initially decreased and then increased，with a spatial distribution pattern of more yield in the south and less yield in the north. The carbon storage showed a continuous decreasing trend. The habitat quality was higher in the south but lower in the north，showing an annual decline. Soil conservation initially decreased and then increased，with an overall upward trend. 2）From 2003 to 2023，the demand for water yield，carbon sequestration，and habitat services generally showed an upward trend. The demand for soil conservation services （soil erosion control）in Anhui Province demonstrated a significant downward trend overall. 3）The comprehensive supply hotspots of ecosystem services in Anhui Province showed a pattern of high in the south and southwest and low in the north. The comprehensive demand hotspots exhibited a pattern of being high in the northwest and lower in the southeast. The comprehensive supply and demand ratio was higher in the south and lower in the north. 4）The ecological supply and demand network in Anhui Province was constructed，identifying 40 supply sources and 36 demand sources，as well as 93 supply corridors and 96 demand corridors. [Conclusion] From the perspective of supply and demand relationship， a multi-objective coordinated ecological supply and demand network is constructed. An ecological supply and demand pattern is formed by building an ecological security barrier in the south and establishing corridors that connect the north，integrated with rivers and basins. This pattern maintains the balance between ecological supply and demand and ensures the normal functioning of the ecological network， providing a scientific basis for the optimal allocation of regional resources and sustainable ecosystem management. These findings help establish a decision-support system with both theoretical value and practical guidance significance.

Abstract:[Objective] Against the backdrop of the dual-carbon goals and sustainable development，this study investigates the critical role of regional carbon ecological compensation mechanisms in addressing the conflict between economic development and ecological preservation during land development and utilization. [Methods] Focusing on Anhui Province， this study constructed a systematic framework of "spatiotemporal differentiation-network connectivity-compensation zoning". Using network analysis，carbon ecological compensation modeling，and the entropy weight-TOPSIS method， a differentiated carbon compensation scheme based on Sustainable Development Goals（SDGs）was established through the K-means algorithm. [Results] 1）During the study period，land-use carbon emissions in Anhui Province increased significantly with notable spatial differences， demonstrating an overall spatial distribution of "high-north-low-south，high-east-low-west". 2）The regional carbon association network gradually formed a "core-periphery" structure centered on Hefei， with Wuhu， Ma'anshan，and Huainan as the main nodes，and the overall network connectivity continued to strengthen. 3）The spatial variation in carbon compensation values was significant ， with total carbon payments and carbon compensation amounts reaching 109.89×10⁸ yuan and 25.23×10⁸ yuan ，respectively. Seven payment zones and ten compensation zones were identified. 4）In line with urban sustainable development ，seven types of carbon-integrated ecological compensation management zones were formed. For each type ， differentiated strategies of "gradient compensation-collaborative governance" were proposed. [Conclusion] The findings offer insights for enhancing regional carbon equity and promoting the coordinated development of the dual-carbon goals and the SDGs，serving as a reference for improving cross-regional ecological compensation policies.

Abstract:[Objective] The study investigates the effects of different light intensities on the photosynthetic characteristics of the invasive species Bidens frondosa and the native species Lactuca indica，aiming to provide a reference for revealing the invasion mechanism of B. frondosa. [Methods] Potted seedlings of the two plant species were used as the materials. Shading shelters were established using black shade nets with light intensities of 100%，40%，24%，and 14%，and differences in leaf photosynthetic characteristics under varied treatments were compared. [Results] 1） Under 100% and 14% light intensities，B. frondosa exhibited significantly higher maximum net photosynthetic rate（P_max）and light saturation point（LSP），but lower light compensation point （LCP）than L. indica. 2）Under 100% and 14% light intensities，the chlorophyll content of B. frondosa was significantly higher than that of L. indica. 3）Under 100% light intensity，B. frondosa showed significantly higher carboxylation efficiency（CE），maximum carboxylation rate of Rubisco（V_c，max），maximum regeneration rate of RuBP（J_max），and photorespiration rate without CO₂（R_p）than L. indica. V_c，max was also significantly higher under 14% light intensity，while R_p decreased under medium and low light intensities and was lower than L. indica. 4）B. frondosa exhibited greater plasticity in P_max，R_d，CE，A_max，R_p，and J_max than L. indica. [Conclusion] The invasive plant B. frondosa shows higher photosynthetic capacity and greater photosynthetic physiological plasticity under different light intensities，indicating a broader adaptability to light intensities.

Abstract:[Objective] To construct a comprehensive adaptability evaluation system for sage（Salvia）and to screen sage species suitable for cultivation in Shanghai（Yangtze River Delta）. [Methods] Using the analytic hierarchy process（AHP），an adaptability evaluation system was constructed comprising five constraint layers and 22 indicator layers to comprehensively assess the adaptability of 120 Salvia species from domestic and international sources. [Results] Resistance/prominent traits and growth vigor were identified as the two main factors representing the adaptability of Salvia in the evaluation system. The adaptability of the 120 tested Salvia species was categorized into four grades from high to low：Grade I（>3.50 points），Grade II（3.00-3.50 points），Grade III（2.50-3.00 points），and Grade IV（≤2.50 points）. Among them，Grade I included 23 original species such as Salvia miltiorrhiza and 10 cultivars such as S. microphylla 'Cerise'，which exhibited the highest adaptability and greatest potential for cultivation in Shanghai. [Conclusion] A comprehensive， rational， and practical adaptability evaluation system for Salvia is established，clarifying the adaptability levels of different Salvia species in Shanghai（Yangtze River Delta）. It provides reference standards and directly selectable species for the introduction and cultivation of Salvia in various regions.

Abstract:[Objective] Land preparation is a key measure in agricultural production in hilly and mountainous areas. It is of great significance to clarify the response relationship between the changes of soil properties after land preparation and the spatial variation characteristics of soil moisture in the field for improving the efficiency of agricultural production. [Methods] Two typical land preparation measures，i. e. horizontal and reverse slopes in hilly and mountainous areas of Guangxi，were taken as the research objects. Field radar detection experiment was combined with indoor soil analysis tests， and the effects of land preparation measures on the variation characteristics of soil moisture in sloping farmland were discussed in depth by means of image analysis and statistical analysis. [Results] Under the same external water supply conditions，the spatial variation of soil moisture after horizontal land preparation significantly occurred in the 0―30 cm soil layer，that after reverse slope preparation was concentrated in the 20―40 cm soil layer，while sloping farmland exhibited moisture variation throughout the entire 0―50 cm soil layer. The spatial distribution of soil moisture in the field of horizontal land preparation was the strongest（average deviation degree 0.052），and the change degree of land preparation on the reverse slope was the weakest. The spatial movement of soil moisture in the field of horizontal land preparation was stable（reflection coefficient 0.33，instantaneous power change rate 8.41×10¹¹ dB/ns）and relatively uniform （radar structure similarity index 0.77），while the degree of soil moisture movement in the field of reverse slope land preparation and sloping farmland was more intense，and the spatial movement state changed greatly. The spatial variation of soil moisture in sloping farmland was the largest（comprehensive index 1.45），followed by reverse slope preparation（comprehensive index 1.53），and the spatial variation of soil moisture in horizontal preparation was the smallest（comprehensive index 1.57），and the soil moisture environment was relatively stable. Compared with sloping farmland，the soil silt content after land preparation had the greatest influence on the spatial variation of soil moisture. [Conclusion] Under the same external water supply conditions，the soil moisture condition in the field after horizontal and reverse slope land preparation is better than that in sloping farmland，and the soil moisture storage condition in the field after horizontal land preparation is better.

Abstract:[Objective] This study aims to investigate the effect of Al₂(SO₄)₃ combined with organic materials on the nitrogen conversion mechanism in saline-alkali soil，and to reveal the effects of different application ratios on soil nitrogen pool. [Methods] This study was conducted on soda saline-alkali soils in the western part of Jilin Province. Three Al₂(SO₄)₃ gradients were applied，corresponding to 0.2%A_0.2，0.1%A_0.1 and 0%A₀ of soil weight，along with three straw gradients，corresponding to 1%S₁，0.6%S₀.6 and 0%S₀ of soil weight. The contents of soil NH₄⁺-N and NO₃^--N，as well as the activities of urease and protease，were measured under both nitrogen fertilization and no nitrogen fertilization conditions. [Results] The application of Al₂(SO₄)₃ improved the average net mineralization and nitrification rates，with the performance of A_0.2S₀>A_0.1S₀. These rates gradually decreased over the incubation period. Incorporating straw into the soil suppressed nitrogen mineralization and nitrification. Despite this suppression，the application of urea fertilizer significantly increased the average net mineralization rate by 17.34 times and the nitrification rate by 3.61 times. However，the inhibitory effect still remained. The combined application of Al₂(SO₄)₃ and rice straw（A_0.1-0.2S_0.6-1）further suppressed the conversion of soil nitrogen. In treatments with high levels of rice straw（S>_0.6），the addition of Al₂(SO₄)₃ accelerated the decline in soil NH₄⁺-N and NO₃^--N levels，which was alleviated by the application of nitrogen fertilizer. Furthermore，the changes in ammonium and nitrate nitrogen contents increased with higher Al₂(SO₄)₃ application rates，following the order of A_0.2S₁>A_0.2S_0.6>A_0.1S₁. The interaction between Al₂(SO₄)₃ and rice straw had significant effects on urease and protease activity，soil total nitrogen，and the concentrations of NH₄⁺-N and NO₃^--N in the absence of urea application. These effects became highly significant following urea application Additionally，significant positive correlations were observed between urease and protease activity and total nitrogen content，between NH₄⁺-N and NO₃^--N，and between net mineralization rate and nitrification rate in the soil. [Conclusion] The combined application of Al₂(SO₄)₃ with high rice straw retains more nitrogen in the soil，with the A_0.2S₁ treatment demonstrating the most efficient nitrogen utilization. These findings offer valuable insights for the reclamation and management of saline-alkali soils and provide a theoretical foundation and practical guidance for future research and application in this field.

Abstract:[Objective] This study aimed to investigate the effects of different types of microbial agents applied during the jointing stage of wheat in a wheat-maize rotation system on soil properties. [Methods] Field experiments were conducted from 2022 to 2024. Four treatments were set up：a water control（CK），application of auxin-producing microbial agent（BS），application of microbial agent（PM），and application of biocontrol microbial agent（BSA）. The impacts of different agents on soil chemical properties，bacterial community structure，and wheat yield were examined. [Results] In the 0—20 cm soil layer，the application of various microbial agents significantly improved soil chemical properties compared to CK（p<0.05）. The PM treatment had the most significant effect on increasing soil alkali-hydrolyzable nitrogen and available phosphorus content（p<0.05），with increases of 22.60%-29.61% and 21.63%-37.51%，respectively，and a significant decline in pH（p<0.05）. There was no significant difference in available potassium content among treatments. In the 20—40 cm soil layer，available phosphorus content in the PM treatment was significantly（22.05%）higher than that in CK（p<0.05），while there were no significant differences in pH，organic matter，alkali-hydrolyzable nitrogen，and available potassium content among treatments. Compared to CK，the application of all microbial agents significantly increased the α -diversity index of rhizosphere soil bacteria（p<0.05），with an increase of 0.73%-7.43%. The application of microbial agents significantly affected the relative abundance of dominant bacterial phyla in the soil. Ninety days after application（p<0.05）， compared to CK， the relative abundance of Proteobacteria in the BS， PM， and BSA treatments increased significantly by 2.70%， 5.42% and 3.71% （p<0.05）， respectively， while the relative abundance of Gemmatimonadetes in the PM treatment decreased significantly by 4.75%（p<0.05）. The relative abundance of bacteria with biocontrol and growth-promoting functions in the rhizosphere soil of all microbial agent treatments was higher than that in CK，while the relative abundance of the pathogenic Nocardioides，which has disease-inducing effects，was significantly reduced at both 15 and 90 days after application（p<0.05）. Compared to CK，wheat yield in the microbial agent treatments increased significantly by 8.28%-20.43% from 2022 to 2023 and by 5.70%-16.23% from 2023 to 2024（p<0.05），with the PM treatment showing the most significant effect. [Conclusion] The application of microbial agents during the jointing stage of wheat effectively activates soil nutrients，enhances bacterial diversity and the abundance of biocontrol and promotive functional bacteria，and increases wheat yield，with the application of Paenibacillus mucilaginosus PM12 being the most effective.

Abstract:[Objective] This study aimed to explore the effects of Scutellaria organic fertilizer on the basic characteristics and microbial community diversity and function of soil under continuous cropping of potato can provide theoretical references for the resource utilization of Scutellaria residue and the improvement of continuous potato cropping soils. [Methods] Using the residue of the medicinal herb Scutellaria baicalensis and sheep manure （with a mass ratio of 1∶3）as the base materials，three organic fertilizer systems（labeled as T1，T2，and T3 in sequence） were prepared by fermentation after adding 3%， 5%， and 10% functional microbial agents respectively. The corresponding treatments after the organic fertilizer was applied to the soil were labeled as F1， F2，and F3，respectively. The effects of the three Scutellaria residue organic fertilizer systems on soil chemical properties，bacterial diversity and function of continuous potato cropping fields were analyzed with the in-situ control trial. [Results] 1）Compared with the control group，all three Scutellaria residue organic fertilizer systems significantly increased the available phosphorus and available potassium contents of the soil at the maturity stage， with increases of 8.12~12.00 mg/kg and 65.63~88.36 mg/kg，respectively. 2）The total population of bacterial flora in potato surface soil was increased by 60.96% and 23.19% in F1 and F2 treatments，and enriched with beneficial genera such as Sphingomonas，Pseudoxanthomonas，and Flavobacterium. 3）LEfSe analysis showed that the application of Scutellaria residue organic fertilizers suppressed the absolute abundance of pathogenic bacteria such as Pectobacterium in the soil，and enriched more beneficial bacterial communities with significantly high absolute abundance that promote soil element cycling. 4）The three kinds of Scutellaria residue organic fertilizer systems altered the function of soil bacterial mediated carbon and nitrogen cycling，and increased the organic matter decomposition potential of soil flora and soil nitrogen availability. [Conclusion] The application of Scutellaria residue organic fertilizer can improve soil available phosphorus and potassium nutrient content，the abundance of beneficial bacterial genera，and bacterial functional activity. The system T1 is the best Scutellaria residue organic fertilizer system.

Abstract:[Objective] This study aims to monitor the Fractional Vegetation Coverage（FVC）in the Chaohu Lake basin and analyze the spatial heterogeneity of its influencing factors， providing a scientific basis for environmental conservation and water resource allocation in the basin. [Methods] Using the Google Earth Engine （GEE）platform，FVC in the Chaohu Lake basin was calculated from 2000 to 2023. The Theil-Sen Median slope estimator，Mann-Kendall trend test，coefficient of variation，and Hurst index were applied to analyze the variation characteristics and trends. Furthermore，the geodetector and Multi-scale Geographically Weighted Regression （MGWR）were employed to explore the spatial heterogeneity of spatiotemporal changes in vegetation and their influencing factors，and to visualize results. [Results] 1）Areas with FVC>0.4 accounted for 60.96% of the Chaohu Lake basin. From 2000 to 2023，FVC of the basin exhibited an overall upward trend，with 58.21% of its area showing vegetation improvement. However，the analysis suggested a potential reversal from greening to degradation in the future. 2）Geodetector analysis showed significant correlations between all influencing factors and FVC. Moreover， interactive detection demonstrated that two-factor interactions significantly strengthened the explanatory power for FVC. 3）MGWR results showed pronounced spatial heterogeneity in the effects of various influencing factors on vegetation across the Chaohu Lake basin. 4）Different influencing factors showed distinct scales of impact on FVC in the Chaohu Lake basin，with GDP，sunlight duration，and elevation as global-scale determinants， while the remaining factors were local-scale variables. [Conclusion] The findings effectively elucidate the spatial heterogeneity of different influencing factors，providing quantitative evidence and theoretical foundations for ecological conservation in the Chaohu Lake basin，which contributes to regional sustainable development.

Abstract:[Objective] To investigate the effects of land use and cover change（LUCC）on carbon stocks of specific soil types in northeast China. [Methods] Based on the obtained soil organic carbon（SOC）stock data and land cover data from 1990 to 2020，ArcGis was used for spatial analysis to extract long-term cropland and land type conversion periods. LUCC dynamics and their influencing mechanism on SOC stocks were analyzed. [Results] 1）From 1990 to 2020，the study area generally maintained as a carbon source，with SOC stocks decreasing by 0.046 Pg. Specifically，SOC stocks in croplands and wetlands decreased by 0.111 Pg and 0.007 Pg， respectively，while those of other land-use types declined by 0.313 Pg. In contrast，SOC stocks in grasslands and forests increased by 0.102 and 0.283 Pg，respectively. 2）Long-term cultivation resulted in a loss of 0.341 Pg of SOC stocks. Reclamation of natural lands（forests and grasslands）led to SOC losses of 5.79% and 4.32%，respectively. 3）Land-use changes were mainly reflected in a decrease in cropland area（11 917 km² ）and an increase in forest and grassland areas（1 535-4 213 km² ）. Wetlands decreased by 1 185 km²，primarily occurring in Inner Mongolia and Heilongjiang（89.00%）. 4）The decreased cropland area was mainly converted into grasslands（64.00%） and other land types（29.00%），with meadow soil，dark brown soil，and chernozem being the main soil types. Wetland loss mainly occurred in black soil and meadow soil regions，while the conversion of other land-use types into forests and grasslands primarily involved dark brown soil（15.00%-41.00%）and meadow soil. [Conclusion] Changes in SOC stocks in northeast China are mainly driven by natural land reclamation and long-term cultivation，as well as the policies of returning croplands to forests and grasslands and the demand for ecological restoration. In the future， efforts should be strengthened to restore croplands and wetlands and to protect forests and grasslands in Heilongjiang，so as to enhance SOC stocks.