The Horqin Sandy Land is a typical area of land desertification evolution in the semi-arid grassland region of northern China. It is a core area for national efforts to control desertification and studying the terrestrial ecosystem's carbon cycle in response to global changes. The Naiman Desertification Research Station， located in the southwestern part of the Horqin Sandy Land and established by the Chinese Academy of Sciences， is a long-term observation and research platform. It is dedicated to preventing and controlling land desertification in the northern agro-pastoral transition zone. This paper reviews four decades of the station's research on carbon cycling in the Horqin Sandy Land， with a focus on the following four areas： ①the carbon content and storage dynamics in the plant-soil systems， ②the soil respiration characteristics， ③the ecosystem carbon flux evolution， and ④the carbon sequestration effects of ecological restoration. This research reveals changes in vegetation and soil carbon pools during both desertification progression and reversal， clarifies the spatiotemporal patterns of regional-scale soil organic carbon and its driving mechanisms， and determines the response thresholds of soil respiration to temperature and moisture alongside shifts in the contribution ratios of its components across different habitats. It also identifies the dominant factors controlling the variability of the carbon sink function in diverse ecosystems over time， based on long-term flux observations， and quantifies the carbon sequestration rates and potential of various ecological restoration measures， elucidating their underlying mechanisms. These findings are profoundly significant in deepening our understanding of the pathways， processes， and mechanisms involved in carbon sequestration and sink enhancement through ecological restoration in semi-arid sandy regions. They also provide crucial scientific support and practical guidance for the precise implementation of China's dual-carbon strategy （carbon peaking and carbon neutrality） in ecologically fragile areas.

Vegetation restoration and reconstruction are key measures for the remediation of desertified lands in arid regions. This process profoundly influences regional carbon cycling by altering surface cover， biodiversity， and soil organic matter. This paper reviews the impact and mechanisms of vegetation restoration and reconstruction on key carbon cycling processes over the past 70 years in the sandy areas of northern China. The results indicate that vegetation restoration enhances photosynthetic carbon sequestration through the "vegetation-biocrust-soil" complex， with net ecosystem carbon exchange （NEE） measurements of -386 to -245， -280 to -156， and -210 to -125 g·m^-2·a^-1 for artificial forests， shrublands， and herbaceous communities， respectively. The annual carbon sequestration by biological soil crusts （BSCs） can reach 11.36 to 26.75 g·m^-2·a^-1. Soil respiration and organic carbon mineralization rates tend to increase with longer vegetation restoration periods. Soil CO₂-C release is regulated by a combination of factors including vegetation composition， restoration duration， BSCs development level， and seasonal hydrological and thermal fluctuations， demonstrating significant spatial heterogeneity and temporal dynamics. Vegetation restoration significantly enhances soil organic carbon （SOC） storage by increasing biomass carbon input， BSC development， and improving soil aggregate structure， with SOC storage in the 0-100 cm soil layer reaching 0.19 to 7.71 kg·m^-2. The sequestration rate is co-controlled by multiple factors such as ecological restoration measures， soil substrate properties， and hydrothermal coupling. The carbon-nitrogen coupling mechanism plays a key regulatory role in the carbon sink function of the system. Vegetation restoration and reconstruction significantly alter the surface greenhouse gas flux pattern， with CO₂ flux dynamics showing complex environmental response characteristics. Future research should strengthen multi-scale long-term monitoring and deepen studies on BSC function， climate change responses， and carbon-nitrogen coupling mechanisms to provide scientific support for optimizing vegetation restoration models in sandy areas and achieving the "dual carbon" goals.

The Great Green Wall project （GGWP） has achieved remarkable accomplishments in combating desertification， effectively curbing ecological degradation and establishing an internationally leading “Chinese model.” The key to its success lies in China’s persistent and continually deepening science-based strategies for combating desertification. This paper systematically reviews and summarizes the transformative process and core connotations of scientific sand control in the GGWP. The main advances are reflected in three deepening aspects： （1） Conceptual deepening： Shifting from a struggle for survival to scientific concepts such as “harmonious coexistence between humanity and nature” and “greening according to water availability，” with an emphasis on systematic governance and sustainability. （2） Technological deepening： Technological innovation has played a vital role throughout， evolving from traditional methods to a new stage of “Technology-Driven Combating Desertification 2.0，” integrating remote sensing， big data， water-saving irrigation， superior germplasm， biological sand fixation， and intelligent equipment， thus increasing precision and efficiency. （3） Effectiveness deepening： Progressing from single-target ecological restoration to the coordinated improvement of ecological， economic， and social benefits， along with the establishment of a comprehensive scientific evaluation system. The scientific practices of combating desertification in the GGWP provide invaluable experience and Chinese wisdom for ecological restoration and sustainable development in arid and semi-arid regions， both in China and worldwide. This paper also offers targeted recommendations for building a greener， more ecological， more beautiful， and happier “Three Norths，” serving as a reference for policy-making.

Naiman Banner， a crucial grain production base in the semi-arid agro-pastoral ecotone of northern China， has been facing increasingly severe water resource shortages. With continuous expansion of agricultural land， the groundwater depth in this region has shown a persistent increasing trend. Based on long-term monitoring data from 25 groundwater observation wells， this study divided the study area into three subregions： Zone I （northern farmland）， Zone II （central sandy area）， and Zone III （southern mountainous area）， according to land use and elevation characteristics. The spatiotemporal evolution of groundwater depth from 1985 to 2020 was analyzed using the Kriging interpolation method. The results indicate that： （1） Groundwater depth exhibited an overall increasing trend， with a temporary rise during 1995-1999 due to increased precipitation. （2） Seasonal variations in groundwater depth differed among subregions due to distinct dynamic patterns. Interannually， Zone I showed the fastest annual increase （0.22 m）， significantly higher than Zone II and Zone III （both 0.09 m）， with Daqintala Town experiencing the most pronounced rise. （3） Land use conversion among cropland， grassland， bare land， and built-up areas was most significant， particularly cropland expansion in Zone I and urban development in Zone II， which exerted decisive impacts on groundwater depth changes. （4） Before 2000， meteorological factors dominated groundwater depth variations across all subregions， whereas after 2000， interactions between irrigation area and other driving factors intensified in Zone I， while Zone II remained primarily influenced by temperature and evaporation， and Zone III showed increasing interactions between precipitation and irrigation area. This study provides a scientific basis for understanding groundwater dynamics in Naiman Banner and offers critical insights for regional water resource management and sustainable development.

Understanding the spatial pattern of soil and microbial carbon， nitrogen and phosphorus （C∶N∶P） stoichiometry and its drivers are important for regulating ecosystem function and responding to global climate change. In this study， we applied geostatistical methods and constructed a random forest model to quantify the drivers of the spatial distribution of soil and microbial C∶N∶P stoichiometry in the Horqin Sandy Land through a regional field survey. The results showed that low-value zones for soil microbial carbon （MBC）， nitrogen （MBN） and phosphorus （MBP） were primarily located in the central part of the Horqin Sandy Land. In contrast， high-value zones were mainly found in the northern part of the Horqin Sandy Land， specifically in the foothills of the Greater Khingan Mountains. The ratios of MBC∶MBP and MBN∶MBP gradually increased from south to north. In the Horqin Sandy Land， the MBC∶MBN ratio ranged from 0.63 to 28.29 （average： 7.3）， the MBC∶MBP ratio from 0.35 to 91.27 （average： 11.26）， and the MBN∶MBP ratio from 0.07 to 10.16 （average： 1.56）. These values were all lower than the global and Chinese stoichiometric ratios. Overall， the region exhibited limitations in C， N and P， with MBC and MBN content primarily influencing the spatial variation of soil microbial biomass C∶N∶P in the Horqin Sandy Land.

The construction of large-scale desert photovoltaic power stations not only provides a new way for global energy transformation and carbon neutrality， but also opens up a new scheme for desertification control. However， the impact of its construction mode on soil physical properties （such as moisture， temperature and electrical conductivity） and the growth characteristics of sand fixation plants is still lack of comparative research in space. This study takes the large-scale new energy base in Tengger Desert as the research object， through field investigation， positioning monitoring and comparative analysis of the soil characteristics， plant growth status and biomass characteristics under， in front of and behind the photovoltaic panels in the ecological restoration area under the two photovoltaic construction modes （fixed adjustable mode and horizontal uniaxial tracking mode）. The results showed that the soil moisture in the fixed and adjustable ecological restoration area was significantly higher than that in the flat uniaxial ecological restoration area， while the soil moisture in the flat uniaxial ecological restoration area was higher than that in the fixed and adjustable ecological restoration area， and the soil temperature and conductivity in the fixed and adjustable photovoltaic ecological restoration area were higher than that in the flat uniaxial photovoltaic ecological restoration area， but the difference was not significant. The spatial heterogeneity analysis showed that there were significant differences in the effects of the two photovoltaic construction modes on soil properties. The soil moisture in the front （fixed and adjustable） and back （two modes） of the photovoltaic panel was significantly higher than that under the photovoltaic panel， while the conductivity in the under panel area was significantly higher than that in the front and back of the photovoltaic panel. The species diversity of the fixed and adjustable photovoltaic ecological restoration area is higher than that of the flat single axis photovoltaic ecological restoration area. The plant height， coverage， ground diameter， root length， aboveground biomass and underground biomass in the area before and after the photovoltaic panel were significantly higher than those in the area under the photovoltaic panel. Plant coverage， height， ground diameter， root length， aboveground biomass and underground biomass were significantly affected by soil moisture （P<0.05）. The construction of photovoltaic power station has significantly promoted the restoration of sand fixation vegetation by improving plant habitat. The fixed and adjustable mode is more conducive to the vegetation restoration in the area before and after the photovoltaic panel， but is not conducive to the vegetation restoration in the area under the photovoltaic panel. This study reveals the potential of desert photovoltaic power station in improving soil environment and promoting sand fixation plant diversity， and provides a theoretical basis for the scientific implementation of the "photovoltaic+sand control" mode.

Vegetation constitutes a critical nexus among the atmosphere， soil， water， and biosphere. Investigating its spatiotemporal dynamics and driving mechanisms is critical for understanding ecosystem evolution. This study leverages 22-year MOD13Q1 NDVI remote sensing data （2000-2022） and integrates natural factors （digital elevation models， soil types， precipitation， temperature， evapotranspiration） and socioeconomic parameters （land use types， population， GDP）. Analytical techniques including pixel binning models， trend analysis， and geographic detectors were applied to systematically evaluate vegetation coverage patterns and their drivers in the Kubuqi Desert. Results demonstrate a sustained upward trend in vegetation coverage， with an annual growth rate of 0.387% （R²≈0.832）. Seasonal variations reveal peak coverage during June-August and minimal levels in November-January. Notably， 73.62% of the study area exhibited vegetation improvement： the desert core transitioned from extremely low to low coverage grades， the southwest shifted from low-medium to medium-high grades， and the southeast achieved widespread high-grade coverage. Single-factor analysis identified land use types （0.493）， precipitation （0.461）， and population density （0.443） as dominant individual drivers. Multi-factor interaction detection highlights precipitation-elevation synergy （interaction q=0.731） as the most significant combined influence on vegetation dynamics.

The desert ecosystem is one of the most fragile and unique ecosystems in the world. Desert plants， through their distinctive and complex physiological and ecological adaptation mechanisms， are able to survive under extreme conditions such as severe drought， high temperatures， and salinity-alkalinity stress. In recent years， significant progress has been made in the study of stress physiology and ecology of desert plants. This paper provides a systematic review of the adaptive strategies of desert plants in terms of morphological adaptation， water regulation， osmotic adjustment， photosynthetic physiology， and molecular mechanisms. It elucidates how desert plants sustain growth and survival under stressful environments through multi-level optimization of structural morphology， regulation of physiological metabolism， and modulation of gene expression. By summarizing the current research status in these aspects， this review also outlines future research directions， aiming to deepen the understanding of the adaptive mechanisms of desert plants and to provide a theoretical foundation and scientific guidance for ecological adaptation studies and the restoration of desert ecosystems.

The potential of carbon sequestration in typical sandy regions of China has long been overlooked，with a lack of systematic analysis over long time series and quantitative assessments of the driving mechanisms of climate change and human activities. In this study，we employed the CASA and Thornthwaite Memorial models to analyze the spatiotemporal variations in net ecosystem productivity （NEP） across typical sandy areas，including the Mu Us Sandy Land，the Hunshandake Sandy Land，the Horqin Sandy Land，the Hulun Buir Sandy Land，and the Songnen Sandy Land，from 1982 to 2024. We also explored the driving mechanisms of meteorological and human factors on the evolution of NEP. The results show that，by 2024，the average annual NEP of the typical sandy regions was 166.67 g·m^-2·a^-1，with significant spatial differentiation. The carbon sequestration capacity in the eastern regions was notably higher than in the western regions. Among these areas，the Songnen Sandy Land exhibited the strongest carbon sequestration capacity，with an annual NEP of 211.08 g·m^-2·a^-1，while the Mu Us Sandy Land had a weaker carbon sequestration capacity，with an annual NEP of only 122.68 g·m^-2·a^-1. From 1982 to 2024，the overall NEP of these regions showed a decline followed by a recovery，reaching a minimum of 130.68 g·m^-2·a^-1 in 2000 and subsequently rising to 166.67 g·m^-2·a^-1 by 2024. In terms of spatial changes，the areas with increased carbon sequestration accounted for 59.96% （10.03×10⁴ km²） of the total study area，with significant increases covering 57.79% （96 682.67 km²），primarily distributed in the Hulun Buir Sandy Land and the Songnen Sandy Land. In contrast，areas with significant decreases accounted for 35.85% （59 977.05 km²），mostly in the Mu Us Sandy Land and the Hunshandake Sandy Land. Human activities were the dominant factor contributing to the improvement of carbon sequestration，with a relative contribution rate of 49.33%. This study provides scientific evidence for carbon neutrality and ecological conservation in sandy regions.

With the clear proposal and in-depth implementation of the national strategic goal of carbon neutrality and carbon peak， China's desertification areas have ushered in the climax of photovoltaic power plant construction. This initiative not only promotes the development of green energy， but also has a series of complex and far-reaching impacts on the natural environment in the desert area. This paper aims to comprehensively sort out the specific impact of photovoltaic power plant construction on desert ecological environment， and summarize the typical problems and challenges existing in the current model through in-depth analysis of the practical cases of "photovoltaic + ecological governance" model adopted by photovoltaic power plants in some deserts at home and abroad. On this basis， this paper puts forward a series of improvement suggestions and strategies， aiming at providing scientific and systematic guidance for the current and future ecological management work of photovoltaic power stations in desert areas， and providing strong scientific and technological support and theoretical basis for promoting ecological restoration and sustainable development of desertification areas.

Plant adaptability refers to the characteristics optimization and survival ability nourishment of plants on multiple spatial-temporal scales through the processes of water and nutrient elements acquisition， regulation， growth and function maintenance. The sandy land plants in northern China have the characteristics of cold， drought and salt tolerance， wind and sand process resistance， and photophily， which are major basis for species selection， density allocation and management of biological control of desertification， and the theoretical basis for vegetation restoration and land degradation control in sandy land. However， studies on the relationship between sediment， plant water consumption， groundwater depth change and plant community on sandy dune land need to be further strengthened. The results show that the sediment depth of the Horqin Sandy Land gradually increases along the rivers west-eastwards from the mountain to the plain， and the depth of the sandy land in the middle part of the Horqin Sandy Land is the largest， about 200 m. There were significant differences in plant community characteristics among different types of dunes， and the changes in plant composition of mobile dunes were the most obvious. With the increase of land use pressure， groundwater depth increased， which affected the distribution pattern and composition characteristics of plants in Horqin sandy land. Dune fluctuation affects the relationship between plants and groundwater depth change.Water consumption of main plants in sandy land is between 300 mm and 450 mm， which is close to the average annual precipitation. Based on the water consumption of plants and the results of field investigation， the reasonable afforestation density in Horqin Sandy Land was between 225-375 plants per hectare. The restoration rate of desertified land in Horqin Sandy Land has entered a bottleneck period. After 1987， the effect of desertification control was not obvious. This study can provide scientific reference for the protection， control and utilization of desertified land in Horqin Sandy Land and the regions alike.

The rapid development of artificial biological soil crust （BSC） technology for desertification control and ecological restoration has emerged as a new model for managing desertified land and a frontier research focus in arid ecosystem restoration. Artificially cultivated BSC plays a crucial role in accelerating ecological restoration by significantly reducing the time required for BSC formation and development. Under natural conditions， BSC formation typically takes 10 to 20 years， whereas artificial BSC can be established within approximately one year， greatly shortening the stabilization period of sand surfaces and expediting the recovery of ecosystem functions in arid regions. The Shapotou Desert Research and Experiment Station/Ningxia Shapotou National Field Scientific Observation and Research Station for Desert Ecosystems （hereinafter referred to as the Shapotou Station）， established in 1955 and affiliated with the Northwest Institute of Eco-Environment and Resources， Chinese Academy of Sciences， is one of China's key research bases for arid zone ecology. It is also among the earliest institutions to systematically study the theory and application of artificial BSC technology for rapid desertification control. On the occasion of its 70th anniversary， this paper systematically reviews and analyzes the major progress made by the Shapotou Station research team in this field over the past 20 years. Furthermore， it provides a forward-looking perspective on the future development of artificial BSC technology in desertification control research. The study aim to offer a comprehensive and precise understanding of the role of artificial BSC technology in desertification control and its impact on ecosystem functions. Additionally， they provide a scientific basis for the optimization， refinement， and large-scale application of related technologies， ultimately contributing to the continuous improvement of arid-zone ecological environments and sustainable development.

The Horqin Sandy Land suffers from severe land desertification. Research into the spatiotemporal evolution patterns of the wind erosion prevention and sand fixation service holds significant importance for regional ecological security and sustainable development. This study systematically analyzed the spatiotemporal dynamics， driving mechanisms of wind erosion prevention and sand fixation service in the Horqin Sandy Land from 2000 to 2020 using the Revised Wind Erosion Equation （RWEQ） model， the XGBoost-SHAP algorithm， and HYSPLIT trajectory simulations. The results indicate： （1） The wind erosion prevention and sand fixation service exhibited significant spatiotemporal heterogeneity. The sand fixation per unit area showed a trend of initial decrease followed by increase， with a spatial pattern characterized by a higher in the central-southern regions and lower in the northern areas. （2） The XGBoost-SHAP model quantified vegetation coverage as the core driving factor， while interactions among wind days， precipitation， and temperature nonlinearly influenced wind erosion processes. （3） HYSPLIT simulations identified 3 559 sand transport trajectories over the 20-year period， with an overall decline in trajectory frequency， indicating enhanced sand fixation capacity. Cluster analysis revealed four dominant pathways： 31.67% of trajectories moved eastward into the Pacific Ocean， 29.92% influenced northeastern regions （Jilin and Heilongjiang）， 20.46% crossed borders to areas such as North Korea and Japan， and 17.95% migrated southward to China’s southeastern coast. These findings provide a scientific basis for optimizing desertification control strategies and coordinating regional ecological compensation mechanisms， while offering methodological references for studying ecosystem service flows in arid and semi-arid regions.

Studying the characteristics of land use change and exploring pathways for its rational utilization are of great significance for regional sustainable development. Taking the changes in farmland area of the Horqin Sandy Land as an entry point， this paper reviews the historical evolution and current status of farmland area in this region， focusing on the impacts of farmland area changes on regional groundwater and farmland wind erosion. Effective approaches and methods for controlling farmland dust sources are proposed. It is recommended that farmland management in the Horqin Sandy Land include： enhancing the monitor and early warning systems for farmland in dust source areas； strengthening the construction of farmland windbreak systems through comprehensive development and management of shelterbelts to fully leverage their critical windbreak functions； reducing wind erosion and enhancing soil conservation capacity by implementing conservation tillage and winter cover cropping； improving integrated management of soil moisture and nutrients by vigorously promoting water-saving irrigation techniques and soil organic fertilization measures to achieve efficient utilization of water-fertilizer resources and comprehensive enhancement of soil quality. Implement classified treatment and adjusted management for different rainfed and irrigated farmlands to enhance comprehensive governance efficiency.

During the large-scale construction of photovoltaic （PV） power stations in desert regions， the areas beneath the panels often experience secondary wind erosion and sand accumulation due to ground surface disturbance and altered wind flow patterns. These issues seriously threaten ecological recovery and the safety of operational maintenance. To evaluate the windbreak and sand-stabilizing effects of different types of mechanical sand barriers in PV fields， this study selected three typical sand barriers， straw checkerboard， degradable polylactic acid （PLA）， and high-density polyethylene （mesh）， within a PV power station located in the Hobq Desert as the experimental site. The wind speed profile near the surface， surface roughness， and friction velocity under varying wind conditions were analyzed to systematically examine the influence of sand barrier type on wind speed modulation and surface stability. The results indicated that： （1） All three types of sand barriers significantly reduced wind speed within the 0-20 cm near-surface layer， with the mesh barrier showing the highest wind reduction efficiency up to 50% at the 10 cm height. （2） The installation of sand barriers markedly increased surface roughness and enhanced wind speed shear resistance， with the straw checkerboard demonstrating particularly notable effects. （3） All sand barriers effectively increased the friction velocity， with an average improvement ranging from 30% to 68% under wind speeds between 7.85 m·s^-1 and 12.03 m·s^-1. （4） Implementing sand barrier measures in the 200 MW PV power station reduced the average annual power generation loss rate to 2.9%. Furthermore， the annual panel cleaning costs were reduced by an average of ¥97 300 with the installation of the three types of sand barriers. Economic evaluation revealed that straw checkerboard barriers offer advantages such as low cost and wide material availability， whereas mesh barriers combine high wind reduction efficiency with durability. PLA barriers exhibited exceptional sand-fixing performance owing to their superior ground conformity. The findings provide a theoretical basis and technical support for controlling secondary wind-sand hazards in PV power stations situated in sandy areas.

The indicator system of residents' well-being in the Yellow River Basin was constructed based on the human needs theory in this paper， and then the spatio-temporal pattern of residents' well-being in 2000-2023 was analyzed. The spatial relationship between the demand dimension of residents'well-being was explored through coupling coordination degree and relative development degree. Meanwhile， the influencing factors of coupling coordination of demand dimension and residents' well-being were revealed based on geographical detectors. Finally， we summarized the driving mechanism of the spatial and temporal pattern of residents' well-being. The conclusion as follows： （1） During the study period， the growth of basic demand in the Yellow River Basin was slow， and the change of spatial distribution was stable. The development of the remaining dimensions of well-being improved significantly，and the level of demand reached a higher state by the end of the study in most regions. The residents' well-being index in each region continues to rise and the growth rate was different， and the residents' well-being varies greatly among regions. （2） During the study period， the coupling coordination degree of sub-demand in the Yellow River Basin gradually improved. Most regions evolve from low coupling and low coupling to high coupling and high coupling.The whole basin has achieved a high level of well-being development. （3） The temporal and spatial differences of residents' well-being are the result of multiple factors. The main body initiative and government initiative had strong explanatory power to the temporal and spatial differences of residents' well-being，and they were the leading influencing factors. The explanatory power of geographical location and new tourism demand was medium， while the explanatory power of natural background was relatively weak.

The middle reaches of the Yellow River Basin are an important economic core area and growth pole in China. However， the safe boundaries for the sustainable development of key elements of its nature-social system remain unclear. The application of the Safe and Just Operating Space （SJOS） theory is expected to provide a novel assessment perspective for the sustainable development of this region. This study is based on the SJOS theory， taking the four provinces and autonomous region in the middle reaches of the Yellow River Basin （Inner Mongolia Autonomous Region， Shaanxi Province， Shanxi Province， and Henan Province） as the research objects. Using environmental monitoring and socio-economic data available from 1990 to 2023， an indicator system for measuring the natural social systems in the region was constructed to assess the SJOS for sustainable development in the study area. The grey prediction model was used to judge its development trend. The results showed that the SJOS of the four provinces and autonomous region in the middle reaches of the Yellow River Basin showed an overall positive trend in time series， and the current ranking of sustainability in the four provinces and autonomous region from best to worst is： Inner Mongolia Autonomous Region>Shanxi Province>Shaanxi Province>Henan Province. However， currently there are still 29 indicators in the four provinces and autonomous region that have exceeded the threshold. The correlation analysis and prediction results show that there are a total of 6 key factors affecting SJOS in the region. Two natural systems， namely fertilizer usage and freshwater utilization； Four social systems， namely industrial innovation， gender equality， sustainable cities， and decent work and economic growth. In short， the natural-social systems in the middle reaches of the Yellow River Basin are currently facing many challenges， but it still has great potential for sustainable development.

This study explores the impact of the digital economy on the transformation and upgrading of the industrial structure in the Yellow River Basin. Using panel data from 118 prefecture-level cities in China's Yellow River Basin from 2000 to 2022， we empirically examine the effects of the digital economy on the transformation and upgrading of the region’s industrial structure， based on an analysis of the spatial evolution characteristics of the digital economy. Our findings indicate that the digital economy exerts a significant positive impact on the overall transformation and upgrading of the industrial structure in the Yellow River Basin， particularly on industrial upgrading， thus contributing effectively to the region's industrial advancement. However， the digital economy does not show a significant effect on the rationalization of the industrial structure， nor does it significantly influence the structural transformation. The mediation effect analysis suggests that the digital economy promotes the overall upgrading of the industrial structure in the Yellow River Basin through the improvement of the consumption structure and the enhancement of technological innovation. The results of the moderation effect test reveal that environmental regulation negatively moderates the overall transformation and upgrading process of the digital economy and industrial structure. The heterogeneity analysis further demonstrates that the effect of the digital economy on the transformation and upgrading of the industrial structure is more pronounced in regions with advanced digital economic development. Finally， the economic consequence analysis reveals that the digital economy has significantly enhanced the green economic efficiency of the Yellow River Basin， following the transformation and upgrading of its industrial structure. These findings not only enrich the literature on the digital economy and its economic implications but also provide theoretical insights and policy recommendations for regional industrial transformation and high-quality development.

In order to understand soil bacterial community structure characteristics and potential ecological function changes of different afforestation restoration strategies in Hunshandake Sandy land. The enclosed sample plots of Pinus sylvestris， Populus， Salix gordejevii and Hedysarum leave were studied which have been planted in Hunshandak Sandy Land for 20 years. The mobile dune enclosed plots that have been restored naturally for 20 years were used as the control. Through the combination of 16S rRNA gene high-throughput sequencing， PICRUSt function prediction and soil nutrient content determination， the soil restoration of different vegetation restoration strategies in sandy land was investigated. The results showed that： （1） The relative abundances of Proteobacteria and Bacteroidota in the Hedysarum laeve forest were significantly increased by 41.16% and 52.94% respectively， compared with those in the Salix gordejevii forest. The relative abundances of Acidobacteria and Chloroflexi in the Salix gordejevii forest were significantly increased by 64.59% and 55.16% respectively， compared with those in the Hedysarum laeve forest. The relative abundance of Bradyrhizobium， Rhizobium and Mesorhizobium accounted for 3.59%， 0.97% and 0.80% in the Hedysarum laeve forest and 3.50%， 0.82% and 0.83% in the Populus forest， respectively. γ-proteobacteria were the marker bacteria of Pinus sylvestris forest. （2） Through PICRUSt function prediction， the abundance of genes involved in stress resistance was significantly increased. The abundance of membrane transport genes in Populus forest was significantly increased， the abundance of membrane transport and signal transduction genes in Hedysarum laeve forest were significantly increased. The abundance of genes involved in self-growth of Pinus sylvestris forest and Salix gordejevii forest were significantly increased. The abundance of amino acid metabolism and lipid metabolism genes was significantly increased in Pinus sylvestris forest. The abundance of gene in energy metabolism and carbohydrate metabolism of Salix gordejevii forest were significantly increased. These results indicated that the potential ecological function of the sand-fixing forest of Populus forest and Hedysarum laeve forest were more stable than that of Pinus sylvestris forest and Salix gordejevii forest. In conclusion， there were significant differences in soil bacterial communities in different vegetation restoration areas of Hunshandake Sandy Land， which led to different potential functions. Hedysarum laeve forest played an important role in nitrogen fixation and soil nitrogen accumulation in collaboration with soil nitrogen fixing bacteria compared with Pinus sylvestris forest， Populus forest and Salix gordejevii forest.

The Beijing-Tianjin Sandstorm Source Control Project area （BTSSCPA） serves as a crucial ecological barrier in northern China， which has long been subjected to ecological pressures including sandstorms， desertification， and vegetation degradation. There is an urgent need to conduct scientific assessments of the spatiotemporal evolution patterns and driving mechanisms of ecological environment quality in the BTSSCPA. This study monitored and analyzed the ecological environment quality in the BTSSCPA based on the remote sensing ecological index （RSEI）. Leveraging the Google Earth Engine （GEE） platform， we constructed four indicators-heat， greenness， wetness， and dryness-using MODIS datasets to characterize the spatiotemporal patterns of ecological environment quality from 2000 to 2020. The Optimal Parameters-based Geographical Detector （OPGD） was employed to identify key influencing factors. Results were showed on the following： （1） The ecological environment quality of the BTSSCPA demonstrated a significant upward trend from 2000 to 2020. Analysis of ecological environment quality grading revealed a notable reduction in areas classified as "poor" and "relatively poor"， accompanied by a simultaneous expansion of regions categorized as "moderate"， "good"， and "excellent". Distinct spatial heterogeneity was observed in environmental quality distribution， manifesting a clear geographical pattern： superior ecological conditions predominated in southeastern sectors， while northwestern regions exhibited comparatively inferior environmental status. （2） Different factors， classification methods （e.g.， natural breaks vs. quantile） and the number of classification strata critically impacted the explanatory power of ecological environment quality assessments. （3） The influence of factors varied substantially， with annual precipitation and vegetation net primary productivity （NPP） demonstrating the most significant effects on ecological environment quality.

Promoting deep coordination between culture-tourism integration and ecological resilience in the Yellow River Basin is of great practical value to stimulate the kinetic energy of cultural and tourism industry， promote the construction of ecological civilization， and accelerate the basin to a new green path of sustainable development. This study takes nine provinces in the Yellow River Basin from 2011 to 2022 as the research object， and integrates the two composite systems of culture-tourism integration and ecological resilience into the same framework. On the basis of measuring the comprehensive level of the two systems， the Haken model is used to reveal the synergistic effect of the two systems and describe their spatio-temporal evolution. The main conclusions are as follows： （1） During the study period， the level of culture-tourism integration and ecological resilience in the Yellow River Basin was significantly improved， but the level of culture-tourism integration showed a "polarization" pattern， with obvious advantages of culture-tourism integration in the downstream region and prominent ecological resilience in the upstream region. （2） The integration of culture and tourism is the order parameter that dominates the collaborative evolution of the Yellow River Basin system. The overall collaborative level of the basin has an evolutionary trend of rapid improvement - stable operation， and the regional level presents a collaborative pattern of downstream > middle reaches > upstream. （3） The number of high-quality and medium synergistic provinces in the Yellow River Basin increased steadily， and the synergistic level showed a dynamic evolutionary pattern of "gradual decline from east to west" to "central catch-up" and then to "contiguous peak". （4） The public service supply of cultural tourism industry and ecosystem is the main obstacle in the early stage， and the negative impact of pollutant emission and ecological environment governance is gradually emerging. The upstream region needs to improve the basic input and performance output of cultural tourism， while the middle and downstream regions need to focus on the lack of ecological resilience supporting factors and ecological environment issues.

Gobi is a typical arid desert landscape and a major surface type along road in sandy regions. Influenced by underlying surface properties， surface material composition， and sand source reserves， the aeolian dynamic mechanisms and the focus of sand hazard prevention priorities in road engineering differ in gobi regions. This study delved into the differences in near-surface wind dynamics and aeolian transport processes between gravelly gobi surface and sandy-gravelly gobi surface. It systematically summarized the research progress on sand disaster prevention and control in road engineering in gobi regions， focusing on the characteristics， formation mechanisms， protective system， and their effectiveness evaluation of the two types of gobi sand hazards along road engineering routes. It also reviewed the main sand control measures and their applications in gobi road engineering. The sandy-gravelly surface， being a latent potential sand source with a mixed distribution of sand， gravel， and powdery sand layers， made it essential to strengthen the study of aeolian processes on sandy-gravelly surfaces. This helped ensure road safety and enhanced transport capacity in the gobi regions of the western China.

Enclosure is an important way to restore desertified grasslands， which has a significant impact on the structure and function of plant communities. Through the time-space substitution method， the plant communities after 22 and 41 years of enclosure of severely desertified grassland for natural recovery in Horqin Sandy Land were studied， to explore the driving mechanisms of long-term enclosure on vegetation restoration in severely desertified grasslands. The results showed that： （1） Compared with mobile sand dunes （severe desertification and the beginning of restoration）， long-term enclosure significantly increased vegetation coverage， height， and aboveground biomass， while vegetation density increased first and then decreased. （2） With the increasing enclosure years， the plant community evolved from annual grasses （with an important value of 0.75 after 22 years of enclosure） dominated by Setaria viridis to perennial herbaceous plants （with an important value of 0.78 after 41 years of enclosure） dominated by Pennisetum centrasiaticuma， Artemisia scoparia， etc. （3） With the increasing enclosure years， species diversity significantly increased and co-occurrence network relationships become more complex （with average degree increased from 1.47 to 1.60）. （4） Soil chemical and physical properties explained 55.5% of the variation in plant communities. Among them， soil organic carbon， bulk density， and soil moisture content， are the main driving factors. Although enclosure is an effective measure for vegetation restoration in severely desertified grasslands， the community structure， dominant species composition， and species co-occurrence network relationships after 41 years of enclosure differed significantly from sparse forest grasslands （reference for climatic climax community）. The results can provide data support and theoretical basis for the development of adaptive management strategies for vegetation restoration in desertified grasslands.

Plant water-use strategies and adaptation mechanisms under drought stress have long been central topics in arid zone ecohydrology. As a successful model of sand stabilization in China， the artificial vegetation area in the Tengger Desert demonstrates how sand-fixing shrubs maintain ecosystem stability in extreme arid environments through unique ecohydrological adaptations. This paper synthesizes key water acquisition and utilization processes， including root hydraulic redistribution， stemflow and foliar water uptake. It quantifies the allocation proportions of water balance components in typical sand-fixing species Caragana korshinskii and Artemisiaordosica， revealing the multi-path water-use strategies and stability-maintenance mechanisms of these shrubs. Furthermore， a conceptual model of precipitation thresholds is proposed that foliar water uptake dominates as the primary drought adaptation strategy within 0-1 mm rainfall events. Stemflow plays a major role in water utilization within 1-5 mm rainfall events， root-soil interface hydraulic redistribution becomes the key strategy when the rainfall greater than 5 mm. This study enhances our understanding of water use by different functional species in desert ecosystems and provides a theoretical basis for evaluating vegetation stability and trends in arid sandy regions.

As a significant emerging technology in recent years for environmental pollution control and degraded ecological environment restoration， algal-bacterial symbiosis has received extensive attention. The fungal and algal components demonstrate intricate interconnections across physiological and biochemical mechanisms， encompassing physical structural associations， biogeochemical nutrient cycling， and cellular signal transduction pathways. Currently， this technology can be applied to various fields including water pollution control， aquaculture tailwater treatment， and soil remediation， playing a crucial role in the green restoration of the ecological environment. However， current research still faces challenges. The symbiotic mechanism has not been fully clarified， and the long-term stability and controllability of the symbiotic system in complex environments require in depth exploration. This study synthesizes contemporary scholarship on fungal-algal symbiotic systems， this paper analyzes the research progress of the algal-bacterial symbiotic mechanism and ecological restoration practices， looks ahead to the future development direction of algal-bacterial symbiosis， and provides theoretical and practical references for further research in related fields of soil desertification control.

The changes in landscape patterns in the Loess Plateau gully region reflect the variations in regional ecological functions and processes. Their spatial differentiation reveals the spatial disparities in landscape processes and their driving forces， aiding in the spatial understanding of the dynamic changes and characteristics of regional landscape patterns. Taking Qingyang City， Gansu Province， as an example， this study systematically analyzed the spatiotemporal dynamics of regional land use changes and landscape patterns， as well as their ecological responses， based on land use data from 2000 to 2020， using ArcGIS and Fragstats software. The aim was to uncover the spatial differentiation characteristics of land use and landscape pattern changes in a typical Loess Plateau gully region. The results indicate： （1） From 2000 to 2020， the land use structure in the study area underwent significant transformations， showing an overall trend of "continuous decrease in cropland， initial increase followed by stabilization in forest and grassland， and expansion of construction land." The primary transitions of reduced cropland were to grassland， forest， and construction land. （2） The landscape pattern indices did not exhibit a clear temporal trend， but the study area displayed distinct spatial differentiation in landscape patterns. Specifically， patches in the northwestern region showed relatively higher ecological dominance， the central area exhibited greater fragmentation in patch size distribution， and the southeastern edge had relatively homogeneous landscape types with more regular patch shapes. （3） Changes in cropland and grassland areas correlated with landscape pattern indices， while gross domestic product（GDP） and total population were the main drivers of changes in landscape indices. This suggests that over time， the integration of ecological and socio-economic spaces in the study area has been deepening.

Rainfall variation and nitrogen addition significantly influenced the structure and function of grassland ecosystems in semi-arid regions. To elucidate their effects on vegetation community characteristics， soil physicochemical properties， and the regulatory mechanisms underlying biomass formation， a field-controlled experiment was conducted in the sandy grassland of the Horqin Sandy Land during 2021 and 2022. Four rainfall treatments were applied during the growing season （May to September）： a 60% reduction （-60%） and a 60% increase （+60%） in precipitation. To further assess the effects of early-season extreme drought， two additional treatments were established： a 100% reduction for 60 days （-60d） and a 100% increase for 60 days （+60d） from May to June. A nitrogen addition treatment （20 g·m^-2 per year） was also included. The results revealed that changes in precipitation and nitrogen addition had significant but temporally inconsistent impacts on community structure， biodiversity indices， and soil physicochemical attributes. Rainfall reduction notably decreased vegetation cover and increased species density. Among the drought treatments， early-season extreme drought （-60d） imposed a stronger suppressive effect on aboveground biomass than whole-season rainfall reduction （-60%）. Nitrogen addition significantly enhanced vegetation cover and both above- and belowground biomass. However， it also reduced species richness， intensified interspecific competition， and facilitated the dominance of competitive species， resulting in decreased community diversity， lower evenness， and increased dominance. With respect to soil responses， nitrogen addition induced soil acidification， leading to a reduction in clay particle content. Under drought conditions， species with drought-tolerant or drought-avoiding traits and larger individuals became dominant， thereby enhancing community biomass. Nitrogen addition further promoted biomass accumulation by increasing vegetation cover and plant height. Overall， rainfall variability and nitrogen enrichment jointly reshaped vegetation structure， altered resource competition dynamics， and modified soil physicochemical processes， thereby exerting profound effects on the biomass formation mechanisms in semi-arid sandy grasslands.

Horqin Sandy Land is one of the four great sandy lands in northern China. Due to the relatively high level of precipitation and temperature conditions and the unique characteristics of civilization evolution， nomadic and farming civilization alternate development of history. In modern times， the rapid development of agricultural and husbandry production activities derived from the social change and population surge led to the continuous land degradation of Horqin Sandy Land in the past hundred years. The resulting phenomena such as low vegetation coverage and increased wind and sand activities， on the one hand， limit the development of regional agricultural and husbandry economy and the improvement of the living standards of farmers and herdsmen， on the other hand， lead to the deterioration of environmental quality， thus contradicting the demand for high-quality life. Under this background， the state and local governments have implemented a series of major projects， policies and regulations related to ecological restoration in Horqin Sandy land， and relevant institutions have carried out a series of fundamental studies and technology research and development demonstrations related to soil desertification process and ecological restoration in Horqin Sandy Land. In the past 3 decades， the desertified land in Horqin area has achieved effective reversal and sustainable recovery under the joint promotion of scientific theories， policies， regulations and major projects. This paper systematically reviews the research progress related to ecological restoration in Horqin Sandy Land in recent years， and makes a preliminary outlook based on the existing research basis and the major needs of national ecological civilization construction， combined with the current situation and trend of regional development， aiming to provide information support for the effective management and high-quality regional development of Horqin Sandy Land.

The study of water resources and vegetation dynamics in groundwater-dependent ecosystems on the Mongolian Plateau is of great scientific significance for the sustainable utilization of water resources on the Mongolian Plateau. In this study， we used the Mongolian Plateau as the study area， calculated the changes of groundwater reserves on the Mongolian Plateau based on the GRACE gravity satellite， and analyzed the trends of groundwater reserves and their relationships with NDVI， precipitation， and evapotranspiration from 2002 to 2021 by using the Sen slope estimation， the M-K trend test， and Pearson's correlation coefficient calculation method. The results show that：（1） the groundwater storage in the Mongolian Plateau shows an overall decreasing trend in time， and the rate of decrease gradually accelerates； spatially， the groundwater storage in the north and the central part of the Plateau slightly decreases， while in the west and the south it decreases more， and the rate of change of the groundwater storage is -347.38 mm·a^-1， and the rate of decrease of the groundwater in Inner Mongolia is larger than that in Mongolia. （2） The changes in NDVI and groundwater reserves on the Mongolian Plateau are correlated. In the northern and southeastern parts of the Plateau， NDVI and groundwater reserves are negatively correlated， with a significant negative correlation accounting for only 1.39% of the total； in the central part of the Plateau， there is a positive correlation， with a significant positive correlation accounting for 9.33% of the total. （3） Precipitation and groundwater storage changes are correlated on the Mongolian Plateau. In the southwestern part of the Plateau， there is a positive correlation between precipitation and groundwater storage changes， with a significant positive correlation accounting for 5.41% of the area； in the eastern and northwestern parts of the Plateau， there is a negative correlation， with a significant negative correlation accounting for 3.36% of the area. （4） The evapotranspiration on the Mongolian Plateau is a key factor affecting the change of groundwater storage， and the evapotranspiration has a significant effect on the change of groundwater storage. In the northeast of the Mongolian Plateau， the significant positive correlation accounts for 2.87% of the area， and the negative correlation between the northwest and the southeast， and the significant negative correlation accounts for 3.95% of the area. In the future， the area covered by vegetation in Mongolia should be increased and the rate of vegetation increase in Inner Mongolia should be reduced moderately. The study reveals the spatial and temporal variations of groundwater storage on the Mongolian Plateau， and its correlation with the influencing factors. It provides data support for ecological restoration of the Mongolian Plateau.

Understanding ecosystem service （ES） supply-demand relationships is crucial for scientifically evaluating human-ecosystem interdependencies and regional sustainability， thereby informing resource management and ecological conservation strategies. As a representative agro-pastoral ecotone in northern China， Horqin Sandy Land faces severe ecological challenges， yet comprehensive assessments of ES flows and human-earth system sustainability remain scarce. This study developed Ecosystem Service Supply （ESSI） and Human Demand （HMDI） indices to quantify ES evolution and spatial matching patterns （2000-2023）， evaluating sustainability through supply-demand balance diagnostics. Key findings reveal： （1） Grasslands contributed most significantly to ES provision， with supply services and regulation services stabilizing post-2005 after earlier fluctuations； （2） Spatially consistent patterns featured accelerated demand growth along functional zone peripheries， contrasting with declining internal supply； （3） Pronounced spatial mismatches emerged， particularly low-supply/high-demand zones （29%） concentrated in southern-eastern sectors； （4） Limited sustainability transitions occurred （2.55% significant degradation vs. 2.96% improvement）； （5） Synergistic areas dominated （79.94%）， characterized predominantly by negative synergies （concurrent ES-demand declines）， while trade-offs were minimized within functional zones.

Understanding the current status of wildlife baseline resources in nature reserves and timely updating species inventories are crucial for formulating effective biodiversity conservation strategies. From October 2022 to May 2024， this study deployed 136 infrared cameras in the Shapotou Nature Reserve and the surrounding Changliushui area to conduct a baseline survey of wildlife resources. Over a cumulative total of 67 456 camera days， 25 699 valid independent wildlife photographs were captured， identifying 10 species of wild mammals from 5 orders and 8 families， and 52 species of wild birds from 13 orders and 24 families. The results indicate： （1） Two species were classified as National Grade I protected wildlife， and 14 species as Grade II. According to the China Biodiversity Red List， 3 species were assessed as Endangered （EN）， 3 as Vulnerable （VU）， and 7 as Near Threatened （NT）. （2） A total of 54 species of wild mammals and birds were recorded at Huangcao Lake in the Shapotou Reserve， followed by 30 species at Changliushui， 26 species at Xiaohu， and 14 species at Jinsha Island. The top five species by relative abundance index （R_AI） were the Tolai hare （Lepus tibetanus）， goitered gazelle （Gazella subgutturosa）， red fox （Vulpes vulpes）， common pheasant （Phasianus colchicus）， and Eurasian magpie （Pica pica）. （3） Analysis of daily activity patterns revealed that goitered gazelles and common pheasants are diurnal and crepuscular， with the latter being almost inactive at night. Asian badgers， Tolai hares， and red foxes are nocturnal and crepuscular， with the former two being nearly inactive during the day. African-Asian wildcats （Felis lybica） are strictly nocturnal， with significantly higher activity levels at night compared to daytime and twilight periods. （4） The leopard cat （Prionailurus bengalensis） was identified as a new species in the Shapotou Reserve， while the previously reported Chinese mountain cat （F. bieti） was revised to the African-Asian wildcat. This study provides a preliminary understanding of the current status of wildlife resources and the daily activity patterns of key species in the Shapotou Nature Reserve， offering a scientific basis for the development of effective biodiversity conservation strategies and enhanced management practices.

We conducted a comprehensive analysis of the litter decomposition characteristics of 6 dominant plant species and their impacts on soil microbial community structure in the Horqin Sandy Land. We used field-based litter decomposition experiments and microbial high-throughput sequencing technology. The results indicated that the decomposition rate of litter followed the order： Chenopodium acuminatum>Caragana microphylla>Setarria viridis>Artemisia halodendron>Cleistogenes squarrosa>Lespedeza bicolor. The initial nitrogen （N） content， lignin content， C∶N ratio， and lignin∶N ratio of the litter were identified as the critical factors influencing the rate of decomposition. After 15 months of decomposition， Actinobacteria， Proteobacteria， Chloroflexi， and Acidobacteria emerged as the predominant phyla within the bacterial community， while Ascomycota dominated the fungal community. The species diversity and richness of the bacterial community increased significantly， whereas the species diversity of the fungal community decreased markedly. The richness of the fungal community was positively correlated with the initial litter C∶N and lignin∶N ratios， but negatively correlated with the initial N content. Furthermore， the relative abundances of Actinobacteria， and Acidobacteria in the bacterial community， as well as Basidiomycota， Mucormycota， and Zoopagomycota， in the fungal community， were positively associated with the initial cellulose and hemicellulose contents， C∶N ratio， and lignin∶N ratio of the litter.

The northern arid regions of China， as a core area for global desertification control， have significant scientific importance and practical demand for exploring an efficient and stable sand control mode to advance the sustainable management of desertified land in arid areas. This study， focusing on the Horqin Sandy Land， constructs a composite system of two types of sand barriers （1 m×1 m crop straw sand barriers and 2 m×2 m shrub live sand barriers） and three vegetation establishment models （herbaceous monoculture， shrub monoculture， and herbaceous + shrub mixed planting）， and inoculates them with algal crusts， moss crusts， and mixed algal + moss crusts， aiming to clarify the impact of different sand control mode on the vegetation characteristics and the development of biological soil crusts in the Horqin Sandy Land. The results show that in 2022， there were no significant differences in plant height among herbaceous， shrub， and herbaceous + shrub planting methods under different types of sand barriers； however， in 2023， the average height of herbaceous communities significantly exceeded that of shrub and herbaceous + shrub mixed planting communities under no sand barrier， crop straw sand barrier， and shrub live sand barrier configurations. This indicates that the duration of vegetation restoration and the type of vegetation planting significantly affect community height. The vegetation coverage under each type of sand barrier control （bare sand） was about 10%， while the average coverage of herbaceous， shrub， and their mixed plantings reached over 50%. Further analysis revealed that the Shannon-Wiener index， Simpson's diversity index， and Pielou's evenness index of the herbaceous + shrub mixed planting treatment were significantly higher than those of the single planting treatments， indicating that compared to single-species communities， multi-species combinations can more effectively enhance ecosystem diversity. The root biomass of herbaceous， shrub， and herbaceous + shrub under crop straw sand barriers was significantly higher than that under no sand barrier and shrub live sand barriers， with the lowest underground biomass under shrub live sand barriers， possibly due to the competition for soil nutrients between shrub live bodies and planted vegetation， affecting the growth of plant roots. Therefore， in terms of sand barrier setting， crop straw sand barriers are relatively ideal types of sand barriers in the process of desertified land restoration. The addition of exogenous crusts in the control plots significantly increased the coverage of biological crusts， while all treatments had no significant effect on crust thickness. This study proposes a herbaceous + shrub mixed planting model based on 1 m×1 m crop straw sand barriers， supplemented with biological soil crust inoculation technology， which can provide an optimized plan for the short-term ecological restoration of the Horqin Sandy Land.

To investigate the impact of the digital economy on energy utilization efficiency and its underlying mechanisms， thereby enhancing energy utilization efficiency in the Yellow River Basin， this study is based on panel data from 78 cities during the period from 2014 to 2023. The non-desired output super-efficiency SBM model and entropy-weighted TOPSIS method are utilized to measure energy utilization efficiency and the digital economy development index， respectively. Furthermore， a bidirectional fixed effects model， mediating effect model， and moderating effect model are employed to analyze the relationship between the digital economy and energy utilization efficiency. The findings indicate that： （1）The energy utilization efficiency in the Yellow River Basin has been continuously improving over the study period； however， and the overall level remains low， with significant spatial disparities characterized by a distribution pattern of "higher in the east and lower in the west". （2） The digital economy exerts a significant positive impact on energy utilization efficiency， particularly pronounced in the downstream regions of the Yellow River. （3） The digital economy enhances energy utilization efficiency by improving industrial structure and technological innovation levels. Additionally， the degree of government intervention significantly moderates the positive relationship between the advancement of industrial structure， technological innovation levels， and energy utilization efficiency.

In extreme environments such as high-altitude cold， arid， and high-temperature regions where the development of vascular plants is restricted， biological soil crusts （BSCs） act as vital living surface coverings and play a crucial role in the ecosystem carbon cycle. To accurately assess the impact of BSC development in extreme environments on the carbon cycle， this paper systematically reviews relevant domestic and international research literature. It comprehensively explores key carbon cycle processes of BSCs， including photosynthetic carbon fixation，respiratory carbon emission， and net photosynthesis， as well as their impacts on atmospheric carbon exchange and soil organic carbon. Additionally， it summarizes the differences in the carbon cycling processes of various BSCs types and under different regional environmental conditions， and elucidates the underlying causes. The comprehensive analysis indicates that BSCs possess strong capabilities for photosynthetic carbon fixation and respiratory carbon emission， and they typically exhibit net accumulation of organic matter under normal physiological conditions. The development of BSCs has a dual regulatory effect on the rate of carbon emission from soil to the atmosphere. In the long term， their development increases the amount of carbon emitted from soil to the atmosphere， thereby enhancing the carbon source effect. The development of BSCs also increases the soil organic carbon content. Moss-dominated BSCs show significantly stronger capabilities in photosynthetic carbon fixation， carbon emission from the BSC-soil system， and promotion of soil organic carbon compared to algae-dominated BSCs. Precipitation and warming are the main factors causing differences in the carbon cycling of BSCs and BSC-soil system across different regions. Under climate change scenarios such as changes in precipitation and increased temperatures， the dynamic responses of BSC carbon cycling and the non-linear responses of carbon exchange between the BSC-soil system and the atmosphere are observed. This study clarifies the mechanisms by which BSC development affects the ecosystem carbon cycle and provides a solid theoretical basis for the scientific management and effective achievement of “carbon neutrality” goals in extreme environments.

Vegetation-based sand fixation is a crucial approach for desertification control and ecological restoration in arid sandy regions of China. The establishment and succession of artificial sand-fixing vegetation profoundly reshape the water cycle processes and water balance patterns within the vegetation-soil system， while hydrological processes， in turn， regulate the structure， function， and ecological stability of plant communities. This paper systematically reviews the key advances in ecohydrological research on sand-fixing vegetation systems， focusing on： （1） the evolution of key hydrological processes and water balance in vegetation-soil systems， particularly canopy hydrological processes， soil water dynamics， and evapotranspiration； and （2） plant growth， vegetation structure， and functional responses driven by hydrological processes， with emphasis on plant water use and regulation， hydraulic adjustment mechanisms， ecohydrological effects of condensation water， and soil water carrying capacity for vegetation. Future research should prioritize multi-scale monitoring， coupled process modeling， and identification of critical ecohydrological thresholds to provide theoretical support for the “greening based on water” strategy in combating desertification.

Vascular plants occupy a dominant position in dryland ecosystems. However， another unique biological component of dryland ecosystems， biocrusts， which play a key role in providing a variety of ecological functions and services and are regarded as the self-organizing principle of dryland ecosystems， has received relatively little attention. Previous studies have tended to examine the roles and impacts of vascular plants or biocrusts in dryland ecosystems separately， thereby neglecting the issue of coexistence and failing to fully understand the mechanisms behind their coexistence. Given that water is a key limiting factor in dryland ecosystems， studying the impact of ecohydrological processes on the coexistence of biocrusts and vascular plants is crucial. In this paper， we first reviewed the coexistence patterns of biocrusts and vascular plants in dryland ecosystems. Then， we explored the effects of major ecohydrological processes （e.g.， precipitation， runoff， and infiltration） on these coexistence patterns. Finally， we clarified the ecohydrological mechanisms behind them， providing theoretical support for vegetation restoration and desertification control in drylands.

The Northwest desert region of China， as a typical ecologically fragile area， where cyanobacterial crust plays cyanobacterial crust playing a crucial carbon-sequestration role， significantly maintaining regional carbon balance and ecological function. Nevertheless， the vertical distribution characteristics of soil organic carbon （SOC） under cyanobacterial crust， especially its fractions （particulate organic carbon （POC） and mineral-associated organic carbon （MAOC）） and their key influencing factors in this region， are not yet clearly understood. This study measured the SOC， POC， and MAOC content in the 0-2， 2-5， 5-10， and 10-20 cm soil depths under cyanobacterial crust in the Northwest desert region， used bare sand as a control， and combined with relevant influencing factors， to clarify the vertical distribution characteristics of SOC components and their influencing factors. The results showed that the SOC， POC， and MAOC content of cyanobacterial crust in each soil depth were higher than those of bare sand， with the most significant differences in the 0-2 cm soil depth. In cyanobacterial crusts， the content of POC and MAOC decreases with soil depth. POC content decreased from 3.83 g·kg⁻¹ at the crust layer to 2.37 g·kg⁻¹ in the 10-20 cm soil depth， and the MAOC content decreased from 2.97 g·kg⁻¹ to 0.95 g·kg⁻¹. In both cyanobacterial crust and bare sand， the proportion of POC content was higher than that of MAOC. The proportion of POC content in bare sand was higher than that in cyanobacterial crust， while the SOC stability of cyanobacterial crust was higher than that of bare sand. Correlation analysis showed that the POC and MAOC content of cyanobacterial crust and bare sand were affected by a combination of climatic factors and soil physicochemical characteristics. In the case of soil organic carbon fractions， they had a significantly positive correlation with total nitrogen， ammonium nitrogen， and available phosphorus， but a significantly negative correlation with pH and mean annual temperature. In addition， mean annual temperature and precipitation were important factors for predicting POC and MAOC content， with mean annual temperature alone contributing 45.50% to predicting POC content in cyanobacterial crusts. This study reveals the carbon-sequestration role of cyanobacterial crust in the Northwest desert region of China， providing a scientific basis for carbon-stock assessment and carbon-sink management in arid region.

As a major ecologically fragile area， the landscape pattern changes in the typical dune alternated with meadow area in Horqin sand directly reflect the interaction between human activities and climate change. Based on the 2000-2020 land use dataset， this study extracted and analyzed the spatial and temporal dynamic characteristics and driving factors of the landscape pattern in the study area from 2000 to 2020， using rainfall， evapotranspiration， soil moisture， Water body area and population size as the driving factors， and using the ArcGIS and Fragstats software. The results show that grassland， unused or other land and cropland were the main landscape types（>93%）in the interspersed areas of dune alternated with meadow area in Horqin sand， the area of grassland and water area gradually decrease， landscape fragmentation increases， connectivity decreases， shape is relatively complex， and landscape heterogeneity shows a decreasing trend. climate change can change the spatial configuration of vegetation cover in the study area， which can lead to the transition of sandy landscapes from a continuous matrix to a fragmentation pattern； and demographic changes can increase the richness of landscape types through land-use diversification. Therefore， climate change and population change can jointly drive the transformation of the landscape pattern， clarify the spatial and temporal differences in the study area， optimize the landscape pattern， and provide technical support for the ecological strategy of sand control and prevention in the region.

Caragana korshinskii is a major shrub species in the Three-North Shelterbelt Forest Program， contributing significantly to ecological protection in arid and semi-arid regions. However， long-term and high-density monoculture management has led to widespread stand degradation， evidenced by diminished growth vigor， reduced natural regeneration capability， and impaired ecological function. Conventional restoration strategies often overlook natural successional processes， fail to enhance biodiversity， and rely on limited and non-targeted mechanical measures. This study was conducted at a degraded Caragana korshinskii site in Yuzhong County Gongjing Forestry. A close-to-nature restoration technological pattern was developed， incorporating selective coppicing， mixed planting， and inoculating biocrusts. The effects of various restoration treatments on stand development and vegetation cover were investigated to identify optimal solutions for stands exhibiting different degrees of degradation. The findings revealed that a 50% coppicing intensity with a stump height of 10 cm significantly improved C. korshinskii growth characteristics and increased vegetation cover， indicating this as the optimal near-natural coppicing regime. For mildly degraded stands， near-natural coppicing （50% intensity， 10 cm stump height） was sufficient. In moderately degraded stands， combining the optimal near-natural coppicing with a 2∶1 mix of C. korshinskii and C. tibetica yielded better restoration outcomes. The most effective technique for severely degraded stands involved a combination of the optimal near-natural coppicing， mixed planting of C. korshinskii and C. tibetica at a 1∶1 ratio， and biocrust inoculation at a coverage exceeding 60%.