Abstract:[Objective] The ecological environment of the Yarlung Zangbo River Basin is fragile. Revealing the spatiotemporal changes in the ecological service functions of the river basin and the trade-off and synergy of dominant functions can provide scientific and technological support for the ecological protection and restoration of the river basin. [Methods] Five critical ecosystem services (habitat quality, water production, soil conservation, carbon sequestration and food supply) were quantitatively assessed within Yarlung Zangbo River Basin using InVEST model. To analyze the spatiotemporal dynamics of ecosystem service functions across various altitudinal gradients and scales, and uncovers the tradeoffs and synergies among these services, Spearman non-parameter correlation analysis and geographical weighted analysis were employed. [Results] (1) From 2000 to 2020, the high values of five ecosystem services supply primarily concentrated in the lower reaches. The Yarlung Zangbo River Basin exhibited higher habitat q

Abstract:[Objective] To reveal the spatial and temporal evolution characteristics of the health status of forest ecosystems in the mountainous areas of Beijing from 2005 to 2020, and to analyze the regional differences and the explanatory power of the influencing factors.[Methods] We constructed a forest ecosystem health evaluation model with “geographic environment-vegetation structure-ecological pressure-vegetation function” as the criterion layer, and applied the entropy weight-TOPSIS method to calculate the weights of the indicators and evaluate the forest ecosystem health of the mountainous regions of Beijing year by year, and analyze the characteristics of the changes in the forest ecosystem health in 2005, 2010, 2015, 2020, and the changes in the forest ecosystem health of the mountainous regions of Beijing. We analyzed the changes of forest ecosystem health in 2005, 2010, 2015 and 2020.On this basis, spatial autocorrelation analysis and K-means clustering analysis were used to explore the spatial aggregation and regional differences in ecosystem health, and the explanatory power of each indicator factor on the spatial distribution of forest ecosystem health was quantified by using the single-factor detection and interaction detection modules in Geographical detector model.[Results]:(1) From 2005 to 2020, the health level of forest ecosystems in the mountainous areas of Beijing will show an upward trend year by year.At this stage, the forest ecosystems in the mountainous areas of Beijing are mainly moderately healthy and relatively healthy, with the proportion of the area in the two areas being 41% and 48%, respectively.The spatial pattern of spatial differentiation is high in the far urban areas and low in the near urban areas. (2) The health status of forest ecosystems in the Beijing mountainous area has been improving year by year, and the change was especially obvious from 2015 to 2020, with the proportion of excellent healthy areas rising from 2.43% to 18.65%.The Moran index in the study area showed a decreasing and then increasing trend from 2005 to 2020, exhibiting significant global spatial autocorrelation and local spatial autocorrelation clustering characteristics.The spatial types of significance were dominated by positive correlation, with 41.8% and 30.8% of HH and LL types, respectively, accounting for 79.6% of the total number of significance types. (3) Soil conservation, LAI, NDVI, tree cover, and population density were the dominant factors of forest ecosystem health in the mountainous areas of Beijing, and the interactions among the factors showed nonlinear enhancement and two-factor enhancement;Forest ecosystem health in Beijing"s mountainous areas was dominated by GDP and soil retention in 2005, by LAI and soil retention in 2010-2015, and by air purification and soil retention in 2020.[Conclusions] From 2005 to 2020, the health of forest ecosystems in the mountainous areas of Beijing has continued to improve, but 27.27% of the area is still in poor or moderate ecological health, with some room for improvement. The spatial distribution of areas with poor health and low-low catchment areas is basically the same, and the construction of ecological protection and restoration projects in forest belts should be strengthened in order to safeguard the ecological health of regional forests.In future forest management and care, the enhancement and maintenance of forest ecosystem services need to be fully considered.

Abstract:[Objective]Exploring the effects of scutellaria-residue organic fertilizer on the basic characteristics and microbial community diversity and function of continuous potato soil can provide theoretical references for the resource utilization of Scutellaria-residue and the soil improvement of continuous cropping potato fields. [Methods] Three kinds of organic fertilizer systems were constructed with the bulk medicinal herb Scutellaria-residue and sheep manure (mass ratio 1:4) as the base material, which were 3% of bacterial additive (F1), 5% of bacterial additive (F2), and 10% of bacterial additive (F3). The effects of three Scutellaria-residue organic fertilizer systems on the chemical properties, soil bacterial diversity and community structure of potato surface soils in continuous cropping were analyzed in conjunction with a controlled field 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 by 8.12~12.00 mg.kg_-1 ^{and 65.63}~88.36 mg.kg_-1^{, respectively;}(2) and the total number of bacterial flora in the potato topsoil was increased by 60.96% in both F1 and F2 treatments, 23.19%, 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 soil carbon and nitrogen cycling functions at significantly higher absolute abundances;(4) the three kinds of scutellaria-residue organic fertilizer systems were able to change the function of the soil bacterial mediated carbon and nitrogen cycle, and increase the soil bacterial flora on the organic matter decomposition potential of soil flora.[Conclusion] The application of scutellaria-residue organic fertilizer can improve the soil available phosphorus and potassium nutrient content, the abundance of beneficial bacterial genera and bacterial functional activity.

Abstract:[ Objective ] Soil 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 change of soil properties after soil preparation and the spatial variation characteristics of soil moisture in the field for improving the efficiency of agricultural production.[ Method ] Two typical land preparation measures of horizontal and reverse slopes in hilly and mountainous areas of Guangxi were taken as the research objects. The field radar detection experiment was combined with the indoor soil analysis experiment, 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. [ Result ] Under the same external water supply conditions, the spatial variation of soil moisture after horizontal soil preparation significantly occurred in the range of 0-30 cm soil depth. The reverse slope preparation was concentrated in the range of 20-40 cm soil depth, and the slope farmland ran through the whole range of 0-50 cm soil depth. The spatial distribution of soil moisture in the field of horizontal soil preparation was the strongest ( average deviation degree was 0.0519 ), and the change degree of soil 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 8.41×10_¹¹ dB/ns ) and relatively uniform ( radar structure similarity index 0.78 ), while the degree of soil moisture movement in the field of reverse slope land preparation and slope farmland was relatively intense, and the spatial movement state changed greatly. The spatial variation of soil moisture in slope 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 slope farmland, the soil silt content after soil preparation has the greatest influence on the spatial variation of soil moisture. [ Conclusion ] Under the same external water supply environment, the soil moisture condition in the field after horizontal and reverse slope land preparation is better than that in the slope farmland, and the soil moisture storage condition in the field after horizontal underground preparation is relatively better.

Abstract:As a bridge between plants and soil, mycorrhizal play a crucial role in regulating the balance of soil carbon (C) pools. Mycorrhizae, by absorbing mineral nutrients from the soil in exchange for C fixed by plant photosynthesis, also contribute to soil C loss through respiration.S The role of mycorrhizal in soil carbon input, carbon stability, and carbon sequestration is well understood; however, knowledge of the effects of mycorrhizal on soil respiration is relatively limited. A review of the effects of mycorrhizal on soil respiration and their regulatory factors is presented. 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, arbuscular mycorrhizal respiration and ectomycorrhizal respiration contribute 18.4% (2.5%-32.0%) and 15.1% (3.0%-62.1%) to soil respiration, respectively. Inoculated mycorrhizal plants increased soil respiration by an average of 26.0% compared to mycorrhizal-free plants. The response of mycorrhizal respiration to soil temperature and soil moisture varied in different 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, and then regulates mycorrhizal respiration. Biological factors such as fine root biomass, extraradical hyphal length density, and plant-supplied substrates also significantly influence mycorrhizal respiration. As an important component of both soil respiration and autotrophic respiration, mycorrhizal respiration contributes substantially to soil C loss, which cannot be overlooked. More precise methods are needed to isolate and quantify mycorrhizal respiration to accurately assess the dynamics of soil carbon cycling and provide scientific insights for global C management and climate change mitigation.

Abstract:Rill erosion constitutes a significant mode of erosion in slope farmlands. To elucidate the impact of diverse planting patterns on the morphological characteristics of rills, this study aims to identify appropriate planting strategies for specific regions.In order to investigate the characteristics of rill erosion on slopeSfarmland with various planting patterns in alpine canyon areas, this study selected several primary planting configurations as research subjects: Zanthoxylum +Plum+Candian fleabane, Zanthoxylum+Cherry +Artemisia indica,SZanthoxylum+SGreenSbean,SPlum+Soybean,San dSthe bare slope was used as a control. The erosion evolution and morphological parameters of hillslope rills underSdifferentSscour dischargeSratesS(6,S10SandS14SL.min_-1^,Srespe ctively) were analyzed utilizing in situ runoff plot scour tests combined with the Structure from Motion (SfM) technique. STheSresultSshowedSthat (1) Under conditions of rill erosion, the eroded area of the slope and the proportion of grid in the southern slope direction for various planting patterns are smaller than those observed on bare slopes. Under conditions of small to medium flow, the surface roughness exhibited a decreasing trend. Additionally, the proportion of grids within the range of 15° to 25° has increased, while the proportion of grids in the range of 60° to 90° has decreased. (2) Compared to the bare slope, the confluence morphology exhibited by various planting patterns is dendritic in nature and displays distinct fractal characteristics. With the exception of the 10 L.min_-1 ^{flow rate, the slope fractal dimension} D for the Zanthoxylum+Plum+Candian fleabane exhibited the highest value. It has a good sand reduction effect. The rill density across all planting patterns surpassed that of the bare slope, while the ratio of rill width to depth was lower than that observed in the bare slope, except for the combinations of Zanthoxylum+SGreenSbean and Plum+SoybeanSunder a scour flow rate of 10 L.min_-1^{. Rill morphology is characterized} as“broad and shallow.” (3) In comparison to micro-aspect and micro-slope, the surface roughness associated with different planting patterns exhibited a stronger correlation with rill morphology (P < 0.01). Stepwise regression analysis indicated that surface roughness is the primary factor influencing the width-to-depth ratio of rills, as well as the density and fractal dimension of various planting patterns. The findings of this research can offer a theoretical foundation for the rational allocation of soil and water conservation measures, as well as for the effective prevention and control of soil and water loss in sloping farmland located in alpine canyon regions.

Abstract:[Objective] Under the dual-carbon goals and sustainable development framework, the development of regional carbon eco-compensation mechanisms plays a pivotal role in reconciling the conflict between economic growth and ecological preservation during land development. [Method] Focusing on Anhui Province, this study establishes an integrated “spatiotemporal differentiation-network connectivity-compensation zoning” framework. Through combined application of network analysis, carbon eco-compensation modeling, entropy weight-TOPSIS method, and K-means algorithm, a differentiated carbon compensation scheme based on Sustainable Development Goals (SDGs) was established. [Result] 1) Significant spatial heterogeneity in net land-use carbon emissions, exhibiting distinct north-south and east-west gradients with higher emissions concentrated in northern and eastern regions during the study period. 2) Emergence of a hierarchical carbon network structure with Hefei as the core node and Wuhu, Ma’anshan, and Huainan as intermediary hubs, demonstrating enhanced network connectivity and core-periphery configuration over time. 3) The spatial difference of carbon compensation value is obvious, the total carbon payment and carbon compensation amount are 109.89×108 yuan and 25.23×108 yuan respectively, and 7 payment zones and 10 compensation zones are identified. 4) Combined with the sustainable development of the city, 7 types of carbon integrated ecological compensation management zones are formed, and the differentiated carbon ecological compensation suggestions of "gradient compensation - collaborative governance" are proposed for each type of area. [Conclusion] The analytical framework and policy recommendations offer critical references for optimizing cross-regional ecological compensation mechanisms and advancing low-carbon spatial governance paradigms. Particularly noteworthy is the novel integration of complex network theory with multidimensional zoning methodology, providing a replicable model for regional carbon management in developing economies.

Abstract:[Objective] Aggregates serve as crucial indicators of soil fertility, and their stability directly influences the physical, chemical, and biological characteristics of the soil. Under salinization and alkalization conditions, aggregates are impacted by the high salinity and strong alkalinity of the soil, which readily give rise to soil structure degradation and functional deterioration, severely constraining agricultural production. [Methods] This article aims to summarize the disparities in aggregates between saline - alkali soil and non - saline - alkali soil, analyze the factors influencing the formation and stability of aggregates under salinization and alkalization circumstances, and explore the methods and strategies for enhancing the aggregate structure in saline - alkali soil, as well as how research on non - saline - alkali soil aggregates can enlighten that of saline - alkali soil. [Results] Comprehensive analysis indicates that the saline - alkali environment undermines the soil structure, reduces microbial diversity and activity, resulting in a decrease in the quantity of large aggregates, an increase in the proportion of micro - aggregates, and poor stability of aggregates. In non - saline - alkali soil, both the number of large aggregates and micro - aggregates are relatively high, with a distinct distribution hierarchy, rich biodiversity, and high stability of aggregates, mainly attributed to the abundant organic matter content and vigorous microbial activities. [Conclusion] To improve the aggregate structure of saline - alkali soil, it is necessary to comprehensively employ hydraulic, physical, chemical, and biological measures to lower the soil salinity and alkalinity content, regulate the pH value, ameliorate the soil structure, enhance the water retention capacity, and increase the nutrient availability. Future research should focus on developing new technical approaches for assessing the aggregate structure, optimizing the improvement techniques, integrating multi - scale data, etc., to facilitate the gradual improvement of the characteristics of saline - alkali soil and the sustainable development of agriculture.

Abstract:[Objective] The karst and non-karst areas in Southwest China are interlaced with strong spatial heterogeneity. Assessing the spatial differentiation and storage of soil organic carbon (SOC) in this region at the county scale is of great significance for achieving regional "dual carbon" goals. [Methods] Taking Wenshan County, a typical karst county in southeast Yunnan Province, as an example, we employed a grid sampling method to conduct the spatial differences in SOC content and storage in top soil(0-20 cm) and deep soil(0-200 cm). Furthermore, we used the semi-variogram function and geographical detector to analyze the impact of external environmental factors on the spatial differentiation of SOC. [Results] The average SOC content in the top soil and deep soil was 17.80 g/kg and 5.18 g/kg respectively, with a total storage of 3770.89×104 t. The distribution pattern revealed higher SOC content in the topsoil of the western region and lower in the central and northern regions, while the deep soil exhibits higher SOC content in the central and western regions and lower in the northeastern region in Wenshan County. In non-karst areas, the SOC content in the topsoil and deep soil was 20.88 g/kg and 6.12 g/kg, respectively, which was 27.94% and 32.75% higher (P<0.01) than in karst areas. The semi-variogram model indicates that the nugget effect value of SOC ranges from 14.62% to 59.93%, indicating that structural factors dominate the spatial differentiation of SOC in Wenshan County. According to the analysis of the geographical detector, temperature and altitude are the main controlling factors affecting SOC in the top soil layer in karst areas. As the temperature decreases and the altitude increases, the SOC content in Wenshan County shows an increasing trend. However, the SOC content in karst areas is generally lower than that in non-karst areas due to their lower altitudes, severe rocky desertification, and relatively poor vegetation growth. For the deep soil, precipitation is the main controlling factor affecting SOC in karst areas. The leaching effect caused by precipitation may combine dissolved calcium with organic matter to form humic acid calcium, promoting the accumulation of SOC in deep soil. In non-karst areas, stratigraphic chronology plays a leading role. The soil developed from Permian basalt parent material may have higher soil clay and macro-aggregate contents, which helps to maintain the physical protection and stability of SOC in deep soil. [Conclusion] This study will provide a reference for the precise assessment of SOC and the regulation of soil carbon pools in the southwestern karst region.

Abstract:Abstract: [Objective] The contents of soil carbon (C), nitrogen (N) and phosphorus (P) along with their stoichiometric ratios, were changed due to the varying nutrient uptake and utilization strategies among various tree species plantations, which in turn affected soil microbial activity. However, whether soil microorganisms adapt to these changes by adjusting their biomass and extracellular enzyme stoichiometric ratios remains uncertain. This study aims to explore the effects of various tree species plantation on soil-microbe-exoenzyme C:N:P stoichiometric ratios and to investigate the correlations among soil-microbe-exoenzyme stoichiometry. [Methods] we conducted an investigation into the contents of C, N and P, as well as microbial biomass C (Cmic), N (Nmic), P (Pmic), and the activities of C (β-1,4-glucosidase + β-D-cellosidase, BG + CBH), N (N-acetyl-β-glucosaminidase, NAG), and P (acid phosphatase, ACP) acquiring extracellular enzymes for microorganisms at depths 0-40 cm in four native tree species plantations. These plantations include conifers Pinus massoniana, deciduous broad-leaved Liquidambar formosana, evergreen broad-leaved Schima superba, and Elaeocarpus decipiens, located in the hilly region of central Hunan province and share a common soil development and management history. [Results] (1) Different tree species plantations significantly affected soil C, N, P content, microbial biomass, extracellular enzyme activity, Cmic:Nmic:Pmic and EEAC:N:P. Cmic:Pmic ratios in the P. massoniana plantations and the L. formosana plantations were significantly higher than those in the S. superba plantations and the E. decipiens plantations, indicating that microorganisms compete with plants for soil available P and a low utilization rate of soil P, especially evident in the L. formosana plantation. NAG and EEAN:P in the S. superba plantations were the highest, suggesting that the microorganism was obviously limited by N. ACP in the E. decipiens forest was higher, EEAC:N and EEAC:P were also higher than those in other tree species plantations, while EEAN:P was the lowest, indicating that the microorganisms were most restricted by C and P. (2) There were no significant correlation between soil C:N:P and microbial biomass, extracellular enzyme C:N:P, while only Cmic:Nmic and EEAC:N, Cmic:Pmic and EEAC:P showed significant negative correlation, indicating no covariance between soil C:N:P and microbial biomass C:N:P. There was a significant positive correlation between soil C:N:P and C:Pimb, a significantly negatively correlation between Cmic:Nmic:Pmic and C:N:Pimb, and a significant positive correlation between C:Nimb and EEAC:N, which confirmed the influence of C, N and P differences between soil and microorganisms on the stoichiometric ratio of extracellular enzymes. (3) Existing biomass of litter layer had significant effects on soil C, N, P content, Pmic, Cmic:Pmic, Nmic:Pmic, BG+CBH, NAG, and EEAC:P. [Conclusion] By influencing the contents of soil C, N and P, plantations composed of different tree species modulated microbial biomass and extracellular enzyme activity. Microorganisms can adapt to diverse nutrient limitations by regulating their biomass C:N:P ratios and synthesizing specific extracellular enzymes, thereby substantiating the microbial resource allocation theory.