Objective, accurate, and timely evaluation of the spatiotemporal changes and driving forces of ecological environment quality is of great significance for the formulation of ecological protection plans and policies. Taking Alxa Left Banner as an example, this study constructs a Remote Sensing-based Ecological Index (RSEI) for arid regions based on the Google Earth Engine (GEE) platform and analyzes the spatiotemporal changes and driving forces of RSEI over the past 30 years (1991-2021). The study shows that: (1) Over the past 30 years, the RSEI of Alxa Left Banner has shown a fluctuating upward trend, with the maximum RSEI in 2012 (0.360) and the minimum in 2007 (0.264). (2) Over the past 30 years, the area of ecological improvement (RSEI>0.2, 3.15%) in Alxa Left Banner is larger than the area of degradation (RSEI<-0.2, 2.48%), with the largest area showing no change (-0.2<RSEI<0.2, 94.37%). Regions with poorer RSEI are mainly distributed in bare land areas, while the RSEI of forest, grassland, farmland, and impervious surface areas has gradually improved. (3) From 1991 to 2021, the Global Moran’s I index ranged between 0.600 and 0.650, indicating a high degree of clustering. (4) According to the results of the linear mixed-effects model, human activities account for 89% of the changes in RSEI, while climate change accounts for 11%. In summary, over the past 30 years, the overall ecological environment quality in the Alxa Desert area has gradually improved, with significant improvements in the northern edge of the Tengger Desert, primarily due to human activities, especially the aerial seeding afforestation projects.

As the scarcity of global water intensifies, accurate assessments of water resource carrying capacity (WRCC) have become essential for sustainably managing regional water resources and combating the adverse effects of climate change. However, the water resources-ecology-society system is highly complex, involving multidimensional interactions anddynamic internal changes that cannot be fully captured by a single evaluation method. This paper reviews the application status and research progress of coupled-model methods for WRCC evaluation. A systematic comparative analysis reveals the strengths and limitations of the major evaluation methods—systems analysis, comprehensive evaluation, and machine learning—in WRCC evaluation. Particular attention is devoted to the challenges of these methods in arid regions. The dynamic feedback mechanisms, nonlinear modeling capabilities, data-driven characteristics, and applicabilities of different methods are analyzed through a horizontal comparison study. The review also analyzes the suitabilities and limitations of each method in arid regions and explores the feasibility of coupled models, providing new insights for resolving WRCC issues in these areas. Multimodel integration and data-driven optimization will enhance the generalizability and applicability of models in future, facilitating the transition of water resource management from static evaluation to dynamic simulation and precise prediction. These developments will offer scientific support for sustainable water resource utilization in arid regions and worldwide.

Agricultural solar thermal resources are the core advantage in the national strategy of the Tarim Basin’s western development. However, there has been no comprehensive quantitative assessment of the potential for developing agricultural solar thermal resources in the Tarim Basin. Based on the analysis of the inter-annual trend and spatial pattern characteristics of agricultural solar thermal resources in 42 counties in the Tarim Basin, this study established a comprehensive evaluation index system and used the entropy-weight TOPSIS method and Mann-Kendall trend test to evaluate the potential for developing agricultural solar thermal resources in the Tarim Basin. The results revealed that (1) between 1990 and 2020, the agricultural solar thermal resources in the Tarim Basin, including annual sunshine hours, annual solar radiation, annual active heat accumulation above 10 ℃, and annual mean temperature, exhibited an upward trend, while the number of days with at least three hours of effective sunshine and annual evaporation displayed a downward trend. (2) a significant spatial imbalance was observed in the agricultural solar thermal resources in the Tarim Basin, and different indicators displayed different spatial differentiation patterns, forming obvious spatial features of high and low agricultural solar thermal resources aggregation distribution. (3) a significant spatial difference was observed in the potential for developing agricultural solar thermal resources in the Tarim Basin, with an average score of 0.199. The highest score of 0.578 was observed in Zhalay County, which was more than six times higher than in Keping County, with 0.094. These results reveal a “multicore” distribution pattern. The findings can provide a realistic reference for the development and utilization of agricultural solar thermal resources in the Tarim Basin and help improve the local resource utilization efficiency.

To examine the mineralization characteristics and their effect on soil organic carbon components in sandy loamy soils following the application of organic fertilizers in conjunction with trace elements, indoor culture experiments and field trials were conducted. We assessed the decomposition rate and residue ratio as well as the influence of varying amounts of organic fertilizer on soil organic carbon, active organic carbon, particulate organic carbon, organo-mineral-bound organic carbon, and microbial carbon content, as well as the level of amino sugars, N-galactosamine, and galactomannan. Compared with the application of organic fertilizers alone, the addition of trace elements to the indoor culture significantly decreased the amount of mineralized organic carbon in the sandy loam soils. In field trials, this addition further increased active organic carbon (1.79%-1.99%), low-active organic carbon (2.20%-4.91%), organo-mineral-bound organic carbon (3.89%-7.95%), and microbial carbon (1.71%-8.10%) content, while also enhancing the level of amino sugars (3.46%-6.32%), N-galactosamine (1.21%-13.32%), galactomannan (2.41%-6.14%), and microbial residual carbon (2.70%-4.99%). However, the increase was less pronounced for high-active organic carbon (0.71%-1.48%) and particulate organic carbon (4.91%-5.86%) content. The addition of micro and trace elements to organic fertilizers may, to some extent, mitigate the mineralization process of organic fertilizers in sandy soils, thereby enhancing the level of labile organic carbon, recalcitrant organic carbon, organic carbon bound with minerals, and microbial biomass carbon in the soil, ultimately promoting the turnover and retention of organic carbon in the soil.

Based on the data from 19 sounding stations in 2022-2023, this study investigates the temporal and spatial variations of the temperature inversions in the lower, middle, and upper troposphere in northwest China. The results indicated the following: (1) In terms of monthly variations, inversions across all three tropospheric levels exhibit similar patterns, peaking in December and January-February of the following year and reaching a minimum from June to August. (2) In terms of spatial distribution, among the low-level inversions, low-level inversions were most frequent in northern Xinjiang, at 40%-60%; the greatest thickness of low-level inversions was observed in northern Shanxi, exceeding 90 m; the intensity of low-level inversions was stronger in most areas of Xinjiang, ranging from 2 ℃ and 3 ℃. For mid-level inversions, their frequency was highest in Qinghai and decrease outward from this region. High-level inversions were most pronounced in northern Xinjiang, with their frequency decreasing outward from this region. (3) The occurrence of low-level inversions in northwest China is influenced by surface radiation and topography, the occurrence of mid-level inversions is associated with warm advection and subsidence movement, and the occurrence of high-level inversions may be related to the top of the temperate troposphere and ozone. (4) In the summer of northwest China, influenced by solar radiation and surface cooling. below the 0 ℃ isotherm height, the intensity of inversions is stronger; above the 0 ℃ isotherm height, the inversions have weaker intensity.

The ongoing decline in biodiversity adversely effects ecosystem services. Investigating spatiotemporal changes in land use and habitat quality in the Three River Source Region is crucial for ecological protection and restoration. This study, based on the PLUS model and the InVEST model’s habitat quality module, conducts multi-scenario simulations to predict land use changes and estimate habitat quality. The results are as follows: (1) During the historical period, 9663.53 km² of grassland converted to unused land, represented the largest proportion of total land conversion, whereas unused land converted to grassland only covered 3659.27 km², the grassland degraded into unused land to a relatively serious extent in the Three River Source Region. (2) Multi-scenario predictions for 2030 reveal that the biodiversity conservation scenario performs best, followed by the grassland protection scenario, then the water resources protection scenario, and finally the natural development scenario. (3) Among conversion types, the contribution rate of converting unused land to grassland in enhancing habitat quality is highest at 0.7167, followed by that of converting unused land to water bodies, at 0.2603. Implementing biodiversity protection strategies, resolving the grass-livestock conflict, and enhancing management of unused land, while reducing grassland-to-unused land conversion will help mitigate the decline in habitat quality.

Wind-sand activities cause surface erosion or accumulation, affecting the safe operation of photovoltaic power plants. This study analyzed the field characteristics of wind speed flow and the erosion variation of photovoltaic panels under different wind speed conditions (6, 8, and 10 m·s^-1) through wind tunnel experiments and numerical simulations to elucidate the mechanism of surface wind erosion in desert PV power plants. The research results revealed that (1) photovoltaic panels change the near-surface wind speed and flow field, forming a front plate airflow lifting zone, a bottom plate airflow acceleration zone, a back plate vortex deceleration zone, and a tail plate airflow recovery zone; the wind speed near the surface of the board significantly increases, making it prone to erosion, while the wind speed behind the board decreases, making it prone to accumulation. (2) when the wind direction is reversed, the “narrow tube effect” under the photovoltaic panel leads to increased airflow, and wind erosion is significantly greater than normal airflow. The accumulation behind the panel is related to the deceleration of the vortex on the leeward side. (3) the wind erosion under the edge array panel of the photovoltaic power station is the most severe, while the wind erosion inside the power station array is relatively light; as the height of the photovoltaic modules increases, the wind erosion under the panels is reduced to some extent. The results provide a scientific basis for sand hazard prevention and efficient production of desert photovoltaic power plants.

The impact of surface O₃ on air quality in China has intensified, making it the primary pollutant for air quality management. As a gateway to Northwest China, Xinjiang has undergone rapid economic development, resulting in air quality issues, particularly in Urumqi and Kashgar. In this study, we analyzed the variation characteristics and potential sources of O₃ in these cities and employed a backward trajectory model to explore transmission paths, potential source areas, and influencing factors. The results indicated the following: (1) From 2015 to 2022, O₃ concentrations in Urumqi and Kashgar peaked in 2018, followed by a slight decrease and subsequent stabilization. O₃ concentrations showed significant seasonal variations, with the highest concentrations occurring in summer, alongside weekend effects and diurnal fluctuations. (2) Backward trajectory analysis revealed that from 2015 to 2022, airflow sources in Urumqi and Kashgar were similar, with long-distance airflows primarily originating from the western Central Asian region. Long-distance transport trajectories account for 31.86% of airflow trajectories in Urumqi, compared to 15.42% in Kashgar. Conversely, medium- and short-distance airflows mainly come from local sources, constituting 68.14% of the trajectories in Urumqi and 84.58% in Kashgar. (3) Urumqi and Kashgar encompass extensive potential source areas. In Urumqi, local sources are the primary contributors, while potential sources in Kashgar include both local and external origins. The range of high-value potential source areas expanded in 2022 compared to 2015.

In this study, we explored the chemical control factors influencing groundwater and the causes of high-fluoride concentrations in the Irtysh River Basin plain, Xinjiang. In 2018, 70 groundwater samples were collected to analyze the spatial distribution characteristics of hydrochemical components and fluoride. The mechanisms behind the formation and enrichment of the high-fluoride water were also examined. Using an absolute factor analysis-multiple linear regression model (APCS-MLR), we quantitatively assessed the contributions of various factors to the hydrochemical components of groundwater in the basin. The results show the following: (1) The groundwater in the study area is generally neutral and slightly alkaline. The north of the Irtysh River is dominated by fresh water, while the south is dominated by brackish water. The rates of fluoride exceedance in the north and south of the Irtysh River are 27.91% and 44.44%, respectively. The primary chemical type of groundwater in both areas is HCO₃·SO₄-Na·Ca type. (2) The results of the SOM analysis suggest that fluoride may be derived from fluorine-containing minerals mixed with various elements. The APCS-MLR model indicates that the formation of groundwater chemical components in the study area is mainly affected by leaching enrichment (58.03%), groundwater pH (16.28%), and the primary geological environment (10.28%). (3) The primary factors influencing the formation of high-fluoride groundwater include mineral dissolution and precipitation, evaporation and concentration, rock weathering, and cation exchange. Additionally, the groundwater environment, climatic factors, topography, and human activities significantly contribute to the enrichment of high-fluoride groundwater.

Using hourly precipitation data collected from automatic weather stations (AWS) in eastern Gansu Province during the summer months from 2010 to 2021, a total of 50 regional heavy rain showers were identified. An analysis was then conducted to examine the spatiotemporal distribution and intensity of such events in eastern Gansu Province. The obtained results can be summarized as follows: (1) The intensity of the heavy rain showers primarily ranged between 20 and 30 mm·h^-1, which accounted for more than 60% of such events. Intensities exceeding 40 mm·h^-1 represented less than 10% of such events. Notably, short bouts of intense precipitation with intensities exceeding 50 mm·h^-1 occurred in 74% of the heavy rain showers in the studied region. (2) In the studied region, heavy rain showers mainly occur from mid-June to late August, peaking in the period from late July to mid-August. While such events occur throughout the year, the interannual variability in their occurrence is significant and closely associated with the position of the Western Pacific subtropical high, the transport of abnormally warm water vapor from the South China Sea or East China Sea, and significant baroclinic features resulting from the interaction of weather systems at mid- and low latitudes. (3) The area typically affected by heavy rain showers in eastern Gansu Province accounts for only 3.17% of its total area. However, there are notable regional variations in the spatial distribution of these events, with areas struck by high-intensity rainfall being primarily located in the Taizishan region, the western section of the Qinling Mountain, Liupan Mountain, and Ziwu Mountain. Additionally, areas affected by rainfall of extreme intensity, exceeding 40 mm·h^-1, are concentrated in these high-incidence centers. (4) There is a clear pattern in the distribution of stations recording heavy rain showers under different circulation patterns. Stations associated with the eastward-moving plateau trough type are dispersed and most abundant. Meanwhile, stations related to the subtropical high’s southwestern airflow type record the lowest median number of such events. Finally, stations experiencing shear between two high-pressure systems are concentrated, while those associated with the northwest airflow type are the least numerous. There was no significant difference in the distribution of the events with heavy rainfall intensity among these circulation types. However, rainfall intensities between 30 and 50 mm·h^-1 are more likely to occur in the two high-shear types.

The characteristics of variation in leaf functional traits of different plant types (shrubs, herbaceous plants) in Hexi Corridor and the relationships between these functional traits are extremely important for maintaining the stability of the ecosystem in this region. To explore the mechanisms of adaptation and the ecological strategies of different plant life forms in arid environments, we established survey sites in the eastern, central, and western sections along Hexi Corridor, following a gradient of decreasing natural precipitation from southeast to northwest. We selected 26 dominant desert plant species, including 14 shrubs and 12 herbaceous plants, and analyzed their variability and regional patterns of 14 key leaf functional traits. We also investigated the trade-offs and adaptive strategies among these traits. The following results were obtained: (1) The coefficient of variation for leaf-bound water content (BW), carbon to phosphorus ratio (C:P), plant height (H), and leaf free water content (FW) of dominant desert plant species in the Hexi Corridor exceeds 100%. (2) Plants in different regions of Hexi Corridor displayed diverse survival strategies: plants in the eastern section adopted a “slow-return” strategy, shrubs and herbaceous plants in the central section exhibited “slow-return” and “fast-return” strategies respectively, while shrubs in the western section adopted a “rapid resource acquisition” strategy under resource-rich conditions, and herbaceous plants adopted a “slow-return” strategy under unfavorable soil conditions. The survival strategies of plants are influenced by multiple ecological factors, and they adapt to arid environments through trait optimization and resource allocation.

In this study, the typical desert plants, Haloxylon ammodendron and Nitraria tangutorum in the sand-blocking and sand-fixing belt of the Hexi Corridor were studied, Through the combination of field survey, sample collection, indoor analysis and statistics, To explore the adaptation strategies of desert plants to arid environment. Select Minqin oasis the sand-blocking and sand-fixing belt and Gaotai oasis the sand-blocking and sand-fixing belt. The natural vegetation sealing protection zone from the upper direction and the downwind tree irrigation shelterbelt, and the sand resistance and sand fixation belt with consistent spatial structure characteristics, Set three 10 m×10 m H. ammodendron quadrats and three 10 m×10 m N. tangutorum quadrats. The spatial distribution characteristics of the main leaf parameters and the environmental factors were analyzed. It aims to provide data support for the evaluation of leaf functional traits in two desert plants. Results showed that, Typical desert plants can adapt leaf functional traits to soil and climatic conditions under specific habitat conditions: (1) Leaf dry material content (LDMC) and specific leaf area (SLA) were significantly different (P<0.05), Leaf organic carbon (LOC), leaf nitrogen (LN) and leaf phosphorus (LP) showed significant differences in the two habitats (P<0.001). (2) Principal component analysis as indicated, The top three index factors affecting the leaf traits of Minqin plants are LN, C:N and C:P; The top three index factors affecting the leaf traits of Gaotai plants are LP, C:N and N:P. (3) Redundancy analysis showed that, soil water content (SWC), soil organic carbon (SOC), and air dryness (AD) are the main limiting environmental factors affecting the functional traits of the two desert plants.

The interaction between wind and water is key in shaping the morphology and spatial distribution of eolian landforms. Quantifying the influence of rivers on eolian landforms has always been challenging. This work selected the Hotan River, which crosses the Taklamakan Desert and the surrounding eolian landforms, as the research object. Based on high-resolution remote-sensing images, DEM and NDVI data, comparing relevant characteristic parameters of typical cross-sections, and analyzing the pattern of eolian landforms and the changes in river channel morphological parameters, the following results were obtained. (1) In the intersection area of the Hotan River and eolian landforms, NDVI=0.05 can be used as a critical value to distinguish the influence of rivers on the pattern of eolian landforms. Consequently, the spatial distribution of the area affected by the Hotan River on eolian landforms is revealed: its area is 20700 km² and its width ranges from 6 to 121 km. (2) The channel morphology of the Hotan River changes little, making it difficult to cause long-distance lateral migration of the river channel; the impact area on the surrounding eolian landforms will not change significantly. In the process of the interaction between wind and water, the Hotan River plays a leading role. Moreover, the southern section belongs to the fully fluvial dominant type, while the northern section belongs to the mostly fluvial dominant type. (3) The distribution pattern of eolian landforms that can be recognized as sabkhas, longitudinal dunes, transverse ridges, and reticulate dunes in sequence from the river channel to both sides results from long-term interactions between wind and water.

To more accurately obtain precipitation distributions in remote areas, this study combined the high-resolution advantages of radar and the wide-coverage detection of satellites. By integrating radar and satellite-derived precipitation, we generated high-precision quantitative precipitation estimation products. Using the strong convective events in Xinjiang on August 12 and 13, 2023, as an example, we used radar reflectivity for precipitation inversion based on cloud classification and Z-R relationships. We fed the Himawari 9 satellite brightness temperature and IMERG precipitation into a BP neural network model to establish the relationship between the average brightness temperature and the average rainfall intensity. Subsequently, we used the instantaneous brightness temperature of the Himawari 9 satellite to invert the momentary precipitation through the BP neural network model. We also proposed two precipitation data fusion schemes: Scheme I uses a uniform correction value to integrate radar and satellite precipitation, whereas Scheme Ⅱ further considers the precipitation intensity levels for comparison. Finally, we obtained high-precision precipitation inversion products for Xinjiang. The results showed that: (1) Cloud classification based on brightness temperature can finely estimate precipitation within the radar range, and brightness temperature differences can reduce the impact of non-precipitating clouds to some extent. (2) The root mean square error (RMSE) of the satellite precipitation inversion was 1.793 mm·h^-1, with a coefficient of determination (R²) of 0.572, indicating reasonable model accuracy. The binary classification score indicated that the model can accurately invert precipitation in over 70% of the areas. (3) The fusion of precipitation by the two schemes slightly improved the accuracy of short-duration light rain distributions. Scheme Ⅱ outperformed Scheme I for short-duration moderate rain but showed a slight decline for short-duration heavy rain compared with Scheme I, indicating that the asynchrony between satellite observation and near-surface precipitation had some impact. (4) Under a 95% confidence interval, the P-values for the RMSE and R² differences between the two schemes and satellite inversion were all less than 0.005, while the P-value for Scheme Ⅱ compared with Scheme I was greater than 0.05. Both fusion schemes significantly improved the accuracy of the satellite precipitation; however, the improvement of Scheme Ⅱ, which considers the precipitation intensity levels, over Scheme I was minimal.

Accurate identification for ecological restoration is essential for promoting sustainable ecological development. Longnan City, as a crucial water source conservation area and ecological security barrier in the upper reaches of the Yangtze River, plays a critical role in maintaining the regional ecological balance. This study used the InVEST model to evaluate ecosystem services and combined the morphological spatial pattern analysis (MSPA) method with circuit theory to construct the ecological security pattern of Longnan City, then analyze its evolution. The results showed: (1) From 2000 to 2022, the number of ecological source areas increased, primarily distributed in the Kang County, Hui County, and Cheng County. The spatial distribution exhibited a pattern of higher density in the south and lower in the north. (2) The average resistance value first decreased then increased, while the length of ecological corridors initially increased and later decreased, during the study period with a net reduction of approximately 508.94 km. Spatially, the corridors shifted from central to southeastern regions. (3) Ecological bottleneck areas, primarily dominated by forests, croplands, and grasslands, were concentrated in low-resistance zones. Their total area decreased annually, with a net reduction of about 144.84 km² over the study period. Ecological obstacles also decreased in both number and area, mainly clustered in Wudu County, Li County, and Tanchang District. Thus, the research results provide a scientific foundation for the formulation of ecological restoration plans and promotion of high-quality regional economic development in Longnan City. The findings provide scientific support for formulating ecological restoration plans and promoting high-quality economic development in Longnan City.

Nitrous oxide (N₂O) a remarkable greenhouse gas in the atmosphere, exerts a pronounced effect on global climate warming. Changes in land use types critically affects N₂O emissions, particularly in ecologically fragile semiarid regions with more complex underlying mechanisms. However, there is still a lack of systematic research on how complex and diverse land use types affect soil N₂O emissions in semiarid regions of China and the key driving factors involved. To address this, this study focused on four typical land use types in the semiarid Loess Plateau of central Gansu Province: Picea asperata forest, Medicago sativa grassland, abandoned land, and wheat field. Soil N₂O fluxes were monitored using the static chamber-gas chromatography method, combined with soil physicochemical property data, to elucidate the key drivers regulating soil N₂O emissions under different land use types. Compared to the abandoned land, the Picea asperata forest and Medicago sativa grassland had significantly increased soil water content, while wheat fields exhibited elevated ammonium nitrogen (NH₄⁺-N) and nitrate nitrogen (NO₃^--N) concentrations. Compared to the abandoned land, the Medicago sativa grassland and wheat fields exhibited markedly enhanced nitrate reductase and nitrite reductase activities, which decreased with an increase in soil depth across all treatments. Soil N₂O fluxes under different land use types exhibited an initial increase followed by a decline during the vegetation growth stages. The total soil N₂O emissions decreased by 34.2% and 23.3% in the Picea asperata forest and Medicago sativa grassland, respectively, and increased by 32.47% in the wheat fields, compared to the abandoned land. Random forest analysis identified soil temperature as the most influential factor affecting the soil N₂O flux. Overall, compared to the abandoned land and wheat fields, the artificial forest and grassland systems in the study area demonstrated superior emission reduction effects. Therefore, future vegetation restoration and ecological rehabilitation efforts should prioritize optimizing the proportional allocation of “forest-grass-cropland” land use types and appropriately increasing the coverage of artificial forests and grasslands to achieve the dual objectives of ecological benefits and emission mitigation.

The microphysical characteristics of a stratiform precipitation cloud in the central Qilian Mountains on August 27, 2022, were analyzed through aircraft measurements. The results revealed significant differences in the cloud microphysical characteristics with different altitudes and regions. The supercooled liquid water content decreased as the altitude increased. In the -6 ℃ to -3 ℃ layer, the mean supercooled liquid water content was about 0.05 g·m^-3, while in the higher layer of -15 ℃ to -12 ℃, the supercooled liquid water content was only 0.015 g·m^-3, less than one-third of the lower layer. The riming process is essential in the growth of particles at all altitudes, with the mean diameter of the particles in the cloud reaching several hundred micrometers. Combining riming and aggregation processes can result in a particle spectrum width of over 6 mm. The mean diameter of the particles in the -6 ℃ to -3 ℃ layer was smaller than that in the upper layer, which may be caused by the evaporation and fragmentation of large particles while falling. On the mountain’s southwestern side, the low-level southerly wind with moisture lifted by the topography resulted in condensation and the production of numerous cloud droplets. The small particle concentration on the mountain’s southwestern side is one order of magnitude higher than that on the northeastern side, and the supercooled liquid water content is also higher. On the mountain’s southwestern side, the cloud particles are mainly supercooled cloud droplets and graupel particles; the aggregation process is not obvious, and the particle concentration is high. On the northeastern side, aggregated ice particles and graupels dominate, and the low concentration of small particles leads to a larger mean size of cloud particles.

This study examines cotton growth affected by soil temperature under the condition of phosphate fertilizer drip application. It also explores the role and mechanism of soil temperature regulation of cotton root growth on improving the utilization rate of cotton phosphate fertilizer. Using potted tests, three soil temperature gradients were examined: low temperature (LT: 11-18 ℃), medium temperature (MT: 22-26 ℃), and high temperature (HT: 30-34 ℃). Single factor testing with water bath temperature control was utilized. The effects of various soil temperatures on the growth traits, biomass, root distribution, effective soil phosphorus distribution, and phosphate utilization efficiency in cotton were assessed. As soil temperature increased, cotton plant height, stem thickness, leaf number and biomass all showed parabolic changes that peaked in the medium temperature (22-26 ℃) group. Additionally, root length in the 0 to 5 cm soil layer increased with soil temperature, most notably with high temperature treatment, followed by low temperature and medium temperature treatments increasing by 5.2%-126.9% and 4.9%-62.3%, respectively. Below the 5 cm soil layer, root length decreased with increasing temperature, with the medium temperature treatment having the longest root length, 81.68%-98.43%, which was 170.17%-218.35% longer than the low temperature and high temperature treatment, respectively. The effective P content of each treatment increased with lower temperatures, with the medium and high temperature treatment content being 13.7% and 20.5% lower than the low temperature treatment, respectively. Phosphorus absorption and phosphate utilization were maximized in the medium temperature cotton, followed by the low temperature cotton. With the lowest high temperature, the total phosphorus absorption in the medium temperature cotton increased relatively by 49.69% and 89.36% compared with low temperature and high temperature treatments, respectively. Furthermore, the phosphate utilization rate was twice and 50% higher than the high and low temperature treatments, respectively. These findings indicate that based on the effects of soil temperature on cotton growth, root and soil effective phosphorus distribution, phosphorus absorption, and phosphate utilization, the most suitable soil temperature for cotton growth is 22-26 ℃.

Investigating the content characteristics of organic carbon components and microbial biomass carbon in farmland soil under different land-use methods is of considerable significance for guiding the rational utilization and management of soil resources in the Ili River Valley. By combining field investigations, sample collection, indoor analysis, and geostatistics, this study explored the content characteristics of soil SOC, POC, DOC, LFOC, EOC, and MBC in five land-use types, including dryland, irrigated land, paddy field, orchard, and abandoned land in the Ili River Valley. This study compared and analyzed the effects of land-use changes on soil organic carbon components and microbial biomass carbon in farmland in the Ili River Valley. Results showed that the contents of TN, AN, AP, and AK in soil were in the order of paddy field>irrigated land>dryland>orchard>fallow land. The nutrient content of paddy soil was significantly higher than that of the other four land-use types. The soil SOC content showed significant differences, primarily reflected in paddy fields (25.62 g·kg^-1)>dryland (13.80 g·kg^-1)>irrigated land (12.19 g·kg^-1)>orchards (11.58 g·kg^-1)>abandoned land (8.81 g·kg^-1), and all reached a significant difference level (P<0.05). The contents of soil SOC, DOC, POC, LFOC, and MBC showed the characteristics of paddy field>dryland>irrigated land>orchard>abandoned land, with significant differences. The EOC content showed the characteristics of paddy field>irrigated land>dryland>orchard>abandoned land, with significant differences. The contents of SOC, DOC, POC, LFOC, MBC, and EOC in paddy soil were significantly higher than those in the other four land-use types. A highly significant positive correlation was detected between soil SOC and POC, LFOC, and DOC in the five land-use types, with the correlation coefficients being 0.622, 0.36, and 0.489, respectively (P<0.01), indicating that soil SOC content is an important factor affecting soil particulate organic carbon, light organic carbon, and soluble organic carbon contents.

Drawing upon China’s comprehensive land use data and socioeconomic panel statistics spanning 1980-2020, this study meticulously analyzed the spatiotemporal evolution characteristics of nonagricultural and nongrain farmland. It aimed to elucidate their underlying patterns of change and driving mechanisms, establishing a solid foundation for sustainable cultivated land utilization and stable food security. Utilizing the SD ellipse and trend analysis, we comprehensively assessed the dynamic evolution traits of these nontraditional agricultural uses. Furthermore, we constructed a comprehensive index system tailored for nonagricultural and nongrain farmlands and developed a partial correlation model to quantitatively assess the relative contributions of various influencing factors. This comprehensive approach offers a nuanced understanding of the intricate dynamics governing these farmland transitions and their implications for China’s agricultural sustainability and food security. (1) Regarding time, the current situation of nonagriculture farmland in China is getting better, but the nonagriculture phenomenon is still prominent in some areas and tends to intensify further. (2) Regarding space, the degree of nonagriculture is more serious in the northeast, central, and eastern regions, while it is higher in the northwest, south, and some coastal areas of southeast China. The polarization phenomenon exists in the direction of nonagricultural chemical evolution. The nongrain center exhibited a development trend of moving from the southwest to the northeast. (3) Economic factors are the leading driving effect of nonagricultural chemistry, and their degree of influence has decreased in the past ten years. Agricultural production condition is the basic factor of nongrain production, and it is gradually increased by economic factors, such as the output value of grain per acre and the income gap between urban and rural areas. The spatiotemporal evolution characteristics and influencing factors of nonagricultural and nongrain lands in China from 1980 to 2020 can provide a reference for the scientific implementation of cultivated land protection decisions.

Land use change is a key factor affecting carbon emissions.Studying the spatiotemporal evolution of regional carbon emissions is significance for promoting reasonable emission reduction. Based on the measured data of land use carbon emissions in Ningxia at two scales of county (district) and 10 km grid from 1990 to 2020, combined with trend analysis, spatial autocorrelation analysis, and GTWR model, this study discusses the spatiotemporal variation characteristics and influencing factors of carbon emissions in Ningxia. The results show that: (1) Both scales of land use carbon emissions show an upward trend in time series, and construction land is the main source of carbon emissions in Ningxia. (2) There are differences in carbon emissions among different counties (districts), with Xingqing District and Lingwu City showing the most rapid growth in carbon emissions. (3) Carbon emissions show a distribution pattern of northwest region>central region>southern region in space. Grid-scale carbon emissions have significant spatial autocorrelation, and the agglomeration pattern of carbon emissions increases with time. (4) The proportion of construction land and human activities are important factors driving the spatial and temporal differentiation of carbon emissions in Ningxia, which has a significant positive effect and the impact intensity increases year by year.

Atmospheric Precipitable Water Vapor (PWV) is an important indicator to characterize the water vapor content in the atmosphere, and clarifying the conversion mechanism between PWV and precipitation is of great significance for efficient water resource utilization. This paper takes Xinjiang as the study area, calculates PWV based on multi-source data, and evaluates the advantages and disadvantages of ERA5 global atmospheric reanalysis data for calculating PWV using radiosounde data as reference, and reveals the conversion relationship between PWV and precipitation with the help of Precipitation Conversion Efficient (PCE). The results show that (1) The PWV calculated by ERA5 has a high accuracy, with correlation coefficients and root mean square errors of 0.98 and 2.6 mm, respectively, compared to the PWV determined by traditional radiosounde data dependent methods. (2) Overall increasing trend of PWV in Xinjiang from 1960-2020, with an increase of 0.1 mm·(10a)^-1; the wavelet spectrum shows that the period of PWV change in the study area is dominated by the short period, which is 2.6 a and 6 a, respectively. (3) From a point perspective, PCE increases with increasing precipitation at the station. From a line perspective, the pattern of change in PCE is “U” type in the direction of longitude and roughly “L” type in the direction of latitude. At the surface scale, the high value areas of PCE were mainly distributed in the forested land, the slope range of 25°-35° and the area above 5000 m above sea level, which were 7.17%, 5.8% and 5.1%, respectively. (4) Typical years of precipitation abundance anomalies vary significantly in PCE, with exceptionally abundant years with strong convergence and strong upward movement of water vapor giving rise to higher PCE, and flat and dry water years with lower PCE. (5) Arctic Oscillation Index and Pacific Decadal Oscillation are the main factors affecting the PCE in the whole of Xinjiang, and there are some differences in the PCE controlled factors among different regions due to differences in climate and topography. The results of the study can provide theoretical references for airborne water resource utilisation and precipitation conversion assessment in Xinjiang.

The sandy lands of northeastern China, located near the edge of the East Asian monsoon zone, are highly sensitive to climate change, making them ideal for investigating the evolutionary history of regional aeolian processes. This study presents optically stimulated luminescence dating of aeolian sediments from two representative profiles situated near the edge of the Horqin Sandy Land (KE) and the Otindag Sandy Land (HS). By integrating sedimentary facies data from the two profiles with additional regional paleoenvironmental records, we reconstructed the regional aeolian evolution history and examined the factors influencing sand and paleosol formation. The results revealed that: (1) The KE profile indicated the development of dark black sandy paleosols between about 9.8 and 3.0 ka, likely reflecting weak aeolian activity. In contrast, thick light gray sandy paleosols formed from around 0.2 ka, indicating intensified aeolian activity and continuous reworking of surface sediments, preventing older deposit formation. (2) In the HS profile, gray-yellow aeolian sand layers were deposited around 13.4 ka, 1.2-0.5 ka, and since 0.5 ka, indicating episodes of strong aeolian activity. Dark black sandy paleosols formed between about 11.6 and 1.9 ka, corresponding to a period of weaker aeolian activity. (3) Since about 13.4 ka, the region has undergone three stages of climatic and aeolian evolution: (i) a warming period from 13.4 ka to the early Holocene, associated with relatively strong aeolian activity; (ii) a warm and humid midHolocene, marked by reduced aeolian activity; and (iii) a late Holocene period of fluctuating cooling, during which aeolian activity increased again. (4) Variations in the timing of dark black sandy paleosol development between the KE and HS profiles, compared with records from the central parts of these sandy lands, suggest that regional topography and paleoclimatic differences may significantly influence aeolian sediment development.

Water supply services sustain the survival and development of human society and are key to promoting the construction of China’s ecological civilization and the high-quality development of river basins. As a significant component of ecosystem services, it is central to ensuring the stability of watershed ecosystems and promoting the construction of ecological civilization in arid and semi-arid regions. This study focuses on the Ili River Valley in Xinjiang, analyzing the equilibrium characteristics of water supply and demand from 2005 to 2020. Using statistical yearbook and remote-sensing data, we apply models of water supply services, the water resources security index (FSI), and supply-demand matching analysis. The results indicate: (1) The FSI of the Ili River Valley fluctuates from “rising to falling,” and the supply-demand balance exhibits a three-stage evolution from “general deficit to general surplus to deficit persistence.” The spatial difference is significant: five counties and cities continue to deficit (i.e., Yining City, Yining County, Huocheng County, Qapqal Xibe Autonomous County, and Xinyuan County), while three counties and one city (i.e., Nilek County, Tekes County, Zhaosu County, and the city of Horgos [2020]) maintain the surplus that appeared in 2010 during the surplus inflection point. (2) The match between water supply and demand presents three dominant types: “low supply-high demand,” “low supply-low demand,” and “high supply-low demand.” The spatial distribution of supply-demand matching types is differentiated by gradients in the east, middle, and west. Counties and cities with the same matching types display spatial agglomeration and industrial convergence. They are significantly driven by the regional economic structure, which manifests in the following ways: the livestock areas with superior ecological fundamentals maintain a high supply capacity, while the arable land-intensive agricultural areas continue to face high demand pressure. To support regional sustainable development, this study analyzes county-level water supply-demand matching in the Ili River Valley, considering socioeconomic and natural geographic factors. Based on the analysis, ecological management zones—conservation, control, and improvement—are defined to promote integrated development, ecosystem sustainability, and efficient water resource use.

Climate change has increased the frequency of long-term droughts and heavy rainfall events, impacting ecosystems’ carbon cycle. Therefore, understanding how soil enzyme activity in different dry/wet conditions affects organic carbon mineralization can help deepen our understanding of the carbon cycle mechanism and advance the goal of global carbon neutrality. This study was based on the unique terraces built to control erosion in the Loess Plateau, and three treatments of flooding stress, drought stress, and wet/dry cycles were designed to monitor soil enzyme activity and organic carbon mineralization. The results indicate that the wet/dry cycle has a transient stimulating effect on organic carbon mineralization, and the cumulative mineralized organic carbon occurs between the drought and flooding stress. At the same time, the wet/dry cycle will increase the activity of carbon and nitrogen cycle-related enzymes; however, the enzyme activity will gradually decrease and stabilize as the number of cycles increases. The enzyme activity in all three water treatment conditions was limited by carbon and phosphorus, and the carbon limitation was more substantial with increasing wet/dry cycles. After the fourth alternating wet/dry cycle, the phosphorus limitation exceeded the flooding and drought stress treatments. When the soil was under drought stress, flooding stress, or wet/dry cycles, the enzyme activity factors that limit organic carbon mineralization were different. The direct effect of the phosphatase factor under drought stress was 99%, the direct impact of EAA_C/N (carbon cycle- /nitrogen cycle-related enzyme) and xyloglucosidase factor under flooding stress was 87%, and the direct effect of the interaction between factors under drought and flooding stress was only 1% and 13%. Under wet/dry cycle conditions, the direct impact of phosphatase and N-acetyl-beta-glucosaminidase factor was 75%, the direct effect of interaction between factors was 25%, and the wet/dry cycle significantly increased the interaction between factors. This study provides theoretical support for clarifying the role of Loess Terrace.

Pixel-based classification struggles with the accurate identification of glacier changes in areas with similar spectral characteristics, particularly in debris-covered areas where spectral features closely resemble the surrounding mountains and rocks, thereby resulting in low extraction accuracy. This study investigates the Yinsugaiti and Yalong Glaciers using Google Earth Engine to integrate spectral indices, microwave texture features, and topographic data. An object-based (OB) machine learning algorithm is applied for automated glacier extraction and compared to pixel-based (PB) classification methods. The results show the following. (1) The OB classification approach, integrating multi-feature fusion, significantly improved the glacier extraction accuracy. The OB_RF classifier achieved an overall accuracy of 98.1%, a Kappa coefficient of 0.97, and an F1-score of 98.67%, outperforming the OB_CART and OB_GTB classifiers. When compared to PB_RF, the overall accuracy, Kappa coefficient, and F1-score increased by 1.7%, 0.024, and 5.57%, respectively. (2) Between 2001-2022, the Yinsugaiti and Yalong Glaciers retreated at average annual rates of 0.08% and 0.13%, respectively. (3) Supraglacial debris was primarily distributed below 5000 and 4800 m on the Yinsugaiti and Yalong Glacier, respectively. Over the same period, debris-covered areas on both glaciers expanded upward.

Water resources form the foundation for maintaining ecosystem balance and ensuring human life and economic development. Simulating hydrological processes in arid and semi-arid ecosystems promotes the effective utilization of local water resources. This paper analyzed the applicability of two models—the Distributed Hydrology Soil Vegetation Model (DHSVM) and the Soil and Water Assessment Tool (SWAT)—in different types of watersheds in semi-arid regions by performing: Sensitivity analysis and parameter calibration. simulation of monthly runoff for the upper reaches of the Xar Moron River and the Laoha River during the growing seasons of 2011-2012 and 2017-2019. The upper reaches of the Xar Moron River are dominated by grasslands, while those of the Laoha River are dominated by forestland and farmland. The results show that DHSVM exhibits 7 primary sensitive parameters in the Xar Moron River and 6 in the Laoha River, whereas SWAT identifies 11 and 12 sensitive parameters, respectively. Following parameter calibration, in the upper reaches of the Xar Moron River the Nash-Sutcliffe efficiency coefficient for DHSVM is 0.70 during calibration and 0.11 during validation, while for SWAT it is 0.43 and 0.04, respectively. In the upper reaches of the Laoha River, the Nash-Sutcliffe efficiency coefficients for DHSVM are 0.56 and 0.70 during the two periods, compared with 0.86 and 0.54 for SWAT. The findings indicate that both models are applicable for simulating hydrological processes in the study area, with DHSVM more accurately simulating overall runoff and SWAT more accurately simulating peak monthly runoff.

Drought is a significant natural disaster in Ordos, exacerbating desertification and degrading grassland vegetation. Therefore, studying drought in this region is crucial for effective drought prevention, desertification control, and ecological restoration. In this study, we explored the spatiotemporal dynamics and trends of drought and analyzed the driving factors behind the spatial differentiation of DSI using a geographic detector model. The results show that evapotranspiration (ET) and the normalized difference vegetation index (NDVI) in the Ordos exhibit a significant increasing trend (P<0.05), with rates of 4.291 mm·a^-1 for ET and 0.004 a^-1 for NDVI. Additionally, the interannual variation of DSI also showed a significant increase, with a trend change rate of 0.089. ET and NDVI showed a spatial pattern, with lower values in the southwest and higher values in the northeast. Conversely, PET showed a spatial pattern of higher values in the southwest and lower values in the northeast. The DSI showed a dry spatial pattern in the west and a wet pattern in the east. The spatial differentiation of the DSI was primarily affected by five factors, such as air temperature, precipitation, land use type, soil type, and the digital elevation model (DEM), with q value exceeding 0.15, indicating these are the main driving factors of drought in the Ordos. Multiple factors interact to drive drought in Ordos, with four key combinations—temperature and DEM, precipitation and DEM, sunshine duration and DEM, and relative humidity and DEM. Among these, the combination of precipitation (0.156) and DEM (0.248) exerted the strongest influence on drought occurrence, with a q value of 0.389. This study can provide a scientific basis for ecological protection and drought management measures in the region.

The effect of environmental factors on the seed germination of two medicinal plants, Asclepias curassavica and Amaranthus tricolor, was studied using PEG-6000, NaCl, and pH gradient solutions to simulate drought, salt, and acidity stresses, respectively. The results provide the basis for their cultivation in arid, saline-alkali areas and the production of high-quality medicinal materials. The findings revealed that the seed germination percentage and index of A. curassavica and A. tricolor decreased with increasing PEG and NaCl concentrations. After 14 days of stress, the nongerminated seeds could rapidly germinate after rehydration and did not lose their vitality. TTC staining of the nongerminated seeds after rehydration revealed that the seeds remained active; the viable seed proportion of the two medicinal plants was significantly higher than in the control or did not decrease significantly, with mean values of 84% and 90%, respectively. At pH 3-6, the A. curassavica and A. tricolor seed germination percentages were 57% and 83%, while the nongerminated seeds of A. curassavica and A. tricolor lost their vitality. The percentages of dead seeds were 10% and 15%, and the proportions of viable seeds were 91% and 87%, respectively, for A. curassavica and A. tricolor. The two medicinal plants displayed a certain tolerance to drought and salt stress and a strong tolerance to acid stress during germination. The two plants can adopt different germination strategies, such as advanced or delayed germination or dormancy, to adapt to their environmental stresses. This study clarified the seed germination characteristics and differences of A. curassavica and A. tricolor under three abiotic stress factors. It provides a theoretical basis for producing and improving the quality of two medical plants.

In this study, we analyzed meteorological data from 1980 to 2020, hydrological runoff data, and future climate models from CMIP6 in the Jinghe River Basin. The CMIP6 climate data was processed using the delta downscaling method and coupled with the Soil and Water Assessment Tool hydrological model to investigate the variations in blue-green water due to climate change in the basin. The results showed that under the SSP1-2.6 pathway, the blue-green water content in the study area exhibited an insignificant upward trend. Under the SSP3-7.0 pathway, the blue water content showed an insignificant downward trend, while the green water content showed a significant upward trend. Similarly, under the SSP5-8.5 pathway, the blue water content showed an insignificant downward trend, and the green water content also exhibited an insignificant upward trend. The average annual blue water volume under the three pathways decreased compared to the historical period, with annual averages of 128.8 mm, 117.2 mm, and 126 mm, respectively. Conversely, the average annual green water volume increased, recording values of 372.7 mm, 369.3 mm, and 372.1 mm, resulting in a green water coefficient higher than that of the historical period. The spatial distribution of blue-green water increased from northwest to southeast, with consistent spatial distribution characteristics across each pathway.

To better understand the response mechanisms of seasonal changes in high-altitude areas to ecological and environmental factors amid global climate change, it is crucial to study the indicators of seasonal early or late and length grade duration classification in Xizang. In this study, we analyzed daily temperature data from 38 meteorological stations in Xizang (1981-2023) using temperature thresholds of 6 ℃, 17 ℃, 17 ℃ and 6 ℃ for four seasons, to explore the classification indices and evolution laws of seasonal early or late and length grade. The results revealed the following: (1) The average start dates for spring, summer, autumn, and winter at the 38 stations were April 21, June 17, July 17, and October 17, with average lengths of 56 d, 29 d, 92 d, and 188 d, respectively. (2) The start and end times, as well as the lengths of the climatic seasons, exhibit characteristics of minimum standard deviation in winter and maximum standard deviation in summer. (3) The start dates, end dates, and length of the climatic seasons, as well as the start and end times and length of the four seasons, showed the following patterns: Normal>slightly early (late) and early (late)>significantly early (late) and abnormally early (late). A indicator is more in line with the threshold of the classification indicators of early or late and length grade. (4) In Xizang, the onset of spring and summer trends was earlier, while autumn and winter had late trends. (5) The start date of spring, the end date of winter, and the length of summer across the 38 stations were primarily classified as normal, whereas the start dates of summer, autumn, and winter, along with the end dates of spring and autumn, were mainly categorized as early. Conversely, the lengths of spring and autumn were mainly classified as short, while winter was predominantly classified as long, and the end date of summer was primarily considered late. These findings provide valuable insights into climate resource management, ecological protection, and the overall impact on human production and life.

Scientifically assessing cloud water resources and studying the distribution and evolution of cloud water resources is of great significance to guide the local weather modification work, accelerate the development and utilization of aerial water resources, and alleviate water shortage. In this study, the monthly reanalysis data of ERA-5 from 1979 to 2022 and the EOF decomposition method were used to analyze the spatial and temporal distribution characteristics of cloud water resources in the Tarim Basin in summer. The following results were revealed. (1) Regarding spatial distribution, the atmospheric water vapor content in the Tarim Basin was higher in the west, lower in the east, and slightly higher in the north than in the south. The water vapor content of the whole layer in the basin displayed an increasing trend in the past 44 years. (2) The two modes of EOF revealed that the water vapor transport in the basin in summer was mainly consistent in the whole region, followed by more water vapor transport in the southwest and less in the northeast. (3) The total cloud cover and cloud water content in summer were higher in the north and south and lower in the middle of the Tarim Basin, and the cloud cover in the mountainous areas was higher than that in the oasis and desert areas. Meanwhile, the cloud ice water content in the north was higher than that in the south of the basin in summer, and the cloud liquid water content in the south was higher than that in the north. The largest cloud liquid water content in the basin was concentrated in the Pamir Plateau, and the peak value of the cloud ice water content was located in the Tianshan Mountains. (4) The mountainous areas and the northern slope of the Kunlun Mountains were dominated by water-bearing medium and low clouds. In contrast, the cloud water thickness in the Tianshan Mountains was deeper, and the cloud ice water content was larger. A significant increase in cloud water content was observed in the mountainous areas of the Kunlun Mountains and the northern slope of the Kunlun Mountains, while a decrease was observed in the Tianshan Mountains after 2000. The results of this study provide a scientific basis for assessing aerial cloud water content and weather modification operations in the Tarim Basin.

Salinization in the irrigation areas of watersheds in downstream arid regions exacerbates soil degradation, crop yield reduction, and river water salinization, severely limiting agricultural production and harming ecological stability. It arises in a manner influenced by the depth of groundwater and poor irrigation and drainage management. Scientifically formulating measures to regulate soil water-salt is key to addressing these issues. In this study, field experiments were conducted in a typical farmland area of the riparian zone by the downstream part of Aksu River. Based on dynamic observations and field survey data, an unsaturated model was established using the HYDRUS-1D software to simulate soil water and salt transport patterns during the cotton growing season, determine appropriate regulatory strategies, and explore the relationship between the stable groundwater evaporation depth and riparian soil structure. The results revealed that the identification and validation accuracy of the soil moisture content and total dissolved solids were 0.862 and 0.752 with root mean square errors of 0.033 and 0.008, respectively, indicating that the model was highly reliable. Irrigation infiltration accounted for 85% of the total soil water recharge, introducing 127.164 mg·cm^-2 of salt, while soil water discharge to groundwater accounted for 59.67% of the total discharge, removing 267.78 mg·cm^-2 of salt. The water balance error was 9.2% and the desalination rate was 33.89%. Considering the demand for water for crops and soil salinity dynamics, setting the irrigation water depth to 70 cm while maintaining the groundwater depth at approximately 220 cm can effectively reduce the soil salinity in the root zone. In sandy loam structures, the position of the loam layer has little effect on the critical evaporation depth of groundwater (150 cm), but significantly influences the stable evaporation depth and actual evaporation. If the loam layer is closer to the surface, the stable evaporation depth becomes shallower and the actual evaporation decreases. The findings provide a reference for preventing salinization and managing water resources in arid regions.

In the Aksu River Basin, 20% of the domestic and irrigation water comes from groundwater, making it crucial to understand the distribution and formation of high-arsenic (As) groundwater in the area. Based on the hydrochemical and isotope results, graphical methods were used to analyze the hydrochemical characteristics of the groundwater and the spatial distribution and forms of arsenic, revealing the As occurrence environment combined with geological, geomorphological, and hydrogeochemical processes. The results revealed that the single-structure phreatic water is alkaline oxidizing brackish water, the phreatic water in the confined water area is alkaline weakly oxidizing saline water, and the confined water is alkaline reducing fresh water. The As content ranged from 0.05 to 160 µg·L^-1, with a rate exceeding the standard of 19.5%. The hydrochemical types of high-As groundwater are mainly Cl·SO₄-Na, SO₄·Cl-Na·Ca, and Cl-Na, distributed in confined and phreatic water in the area downstream of the Aksu and Tailan Rivers at a depth of 10-42 m. From the mountainfront to the fine soil plain, the occurrence environment changes from weakly oxidizing to reducing. The As content and saturation index of the groundwater generally exhibited an increasing trend. The single-structure phreatic water and confined water were mainly controlled by the water-rock interaction. In contrast, the phreatic water in the confined water areas was mainly controlled by the evaporation concentration. The distribution of groundwater As is mainly related to structural factors, with realgar dissolution being the primary natural source. The arid climate and the geological, geomorphological, and hydrogeological conditions create external conditions for the enrichment of high-As groundwater. Factors like pH, desulfurization process, Eh, and groundwater circulation patterns affect As release. This study helps us understand the formation and evolution of high-As groundwater in the Aksu River Basin, which is crucial for ensuring water supply safety.

Soil nutrient levels and microbial community structures are critical indicators for evaluating the ecosystem services of artificial forests. In arid and semi-arid regions, which are the major distribution areas for artificial forests, the regulatory effects of stand density on soil nutrients and microbial communities remain poorly understood. This study analyzed a 30-year-old Robinia pseudoacacia plantation on the Loess Plateau’s eastern edge. Based on Reineke’s stand density effect law and regional management standards, the stands were categorized into low (950-1350 trees·hm^-2), medium (1600-2050 trees·hm^-2), and high (2400-3300 trees·hm^-2) density groups. Data were collected through field surveys, soil nutrient analyses, and high-throughput sequencing of 16S rRNA and ITS. These methods systematically assessed the soil nutrient characteristics and microbial community structures and diversity across different stand densities. The study’s findings indicate that as the stand density increases, the soil total nitrogen, nitrate nitrogen, total carbon, and organic carbon contents significantly increase, especially in the high-density group (P<0.05). Conversely, the available phosphorus content peaks in the medium-density group. The bacterial community was primarily composed of Proteobacteria (38.70%), Actinobacteria (19.37%), Gemmatimonadetes (8.23%), and Chloroflexi (7.71%), with Actinobacteria’s relative abundance significantly increasing alongside the stand density (P<0.05). In the fungal community, Ascomycota (51.79%), Mortierellomycota (30.70%), and Basidiomycota (10.07%) were the dominant phyla. In the high-density group, bacterial and fungal community diversity was significantly enhanced, as evidenced by notable increases in the Shannon and Chao1 indices (P<0.05). Principal Coordinates Analysis revealed that the bacterial community structures in the medium- and low-density groups exhibited significant clustering, distinctly differing from those in the high-density group (P<0.05). In contrast, the fungal community structures remained relatively stable across different stand densities. The Mantel test revealed that bacterial and fungal community structures were significantly associated with TN (P<0.05). Cooccurrence network analysis indicated that moderate stand density increases microbial interaction strength and network complexity. However, when the stand density exceeded 2400 trees·hm^-2, the network stability decreased, potentially hindering efficient resource utilization. Maintaining a stand density of 1600-2050 trees·hm^-2 improves soil nutrient levels and enhances microbial community diversity and stability, providing a scientific basis for the sustainable management of R. pseudoacacia plantations on the Loess Plateau.

Based on the 2022 daily precipitation data from weather stations in the eastern Tibetan Plateau, this study evaluated the accuracy of three datasets from the China Meteorological Administration: the Multi-source Precipitation Analysis System (CMPAS), Land Data Assimilation System (CLDAS), and Global Atmospheric Reanalysis (CRA)—via error indices and grading methods. The results indicate: (1) CMPAS exhibits the lowest error and highest correlation, making it the most reliable for annual precipitation analysis. (2) CMPAS monthly data align closely with observations, while CRA overestimates and CLDAS underestimates precipitation in most months. (3) During two large-scale precipitation events, CLDAS best captures accumulated rainfall, while CMPAS more accurately reflects precipitation centers, intensities, timing, and location. Overall, CMPAS is the most effective dataset for analyzing precipitation in the region, supporting improved monitoring of sparse areas and laying a solid foundation for climate operations and disaster prevention.

The precipitation concentration index (PCI) is a measure of precipitation during the year. Based on the monthly precipitation data of 15 meteorological stations in the Yarlung Zangbo River Basin (YZRB) from 1981 to 2024, the spatiotemporal variation characteristics of PCI, the amount of seasonal precipitation, its frequency and intensity over the last 44 years, and the reasons for a change in PCI were analyzed using a linear equation, Person coefficient, and five mutation tests, including the Mann-Kendall and Cramer tests. The results indicated that (1) The PCI increased from east to west in YZRB, whereas annual precipitation, precipitation frequency, and precipitation intensity decreased from east to west. (2) Over the past 44 years, the PCI decreased at a rate of -0.26 per decade, indicating a trend toward more evenly distributed monthly precipitation throughout the year. Precipitation exhibited an increasing trend from January to July and October (the fastest increase in July), and it decreased in other months (the most in September). Monthly precipitation accounted for the proportion of annual precipitation (MPAP), which increased in February and April-July (the largest in May). MPAP was decreased in other months (the largest decrease in September). (3) The increase of precipitation in spring, summer, and winter was primarily due to the increase in precipitation intensity, whereas the decrease of precipitation frequency played a major role in the decreased amount of precipitation during autumn. Furthermore, the increase in annual precipitation intensity resulted from the significant increase of the Tibetan Plateau-1 index and the western Pacific warm pool intensity index. The decrease in the PCI was related to a decrease in the seasonal difference under the background of warming. (4) The PCI was lower only in the 2000s, but was higher in the other three decades, although there was a sudden change in the early 1990s. The abrupt changes in annual precipitation, frequency, and intensity occurred during the first 10 years of the 2000s and the middle and late 1990s.

Desertification is a serious environmental problem globally, severely restricting the sustainable development of regional economies. In recent years, clay minerals have been widely used for improving wind-eroded and sandy soil, and bentonite with its unique 2:1 layered structure has particularly good prospects for application in the improvement of wind-eroded and sandy soil. In this study, the effects of different proportions of bentonite [without bentonite addition (B0), 2% bentonite addition (B2), and 4% bentonite addition (B4)] on the physical and chemical properties of wind-eroded and desertified soil and plant growth were studied. The results showed the following: (1) Bentonite addition increased the content of fine-grained soil and improved the soil’s water retention and water holding capacity (12%-88%). (2) The shear strength of wind-eroded and sandy soil supplemented with B2 and B4 bentonite was increased by 150% and 205%, respectively, compared with that upon B0 treatment. (3) Bentonite addition can lead to crust formation on the sandy surface, which is beneficial for sand fixation. (4) Among the treatments, B4 bentonite addition significantly increased plant coverage, biomass, and plant height by 32%-33%, 56%-85%, and 71%-107%, respectively. In summary, the addition of bentonite not only improved the soil’s water retention capacity, improved the soil’s physical properties, and fixed the sandy surface, but also promoted plant growth.

Exploring the transition situation of land use in ecologically significant but underdeveloped areas is crucial for promoting urban-rural integration and achieving regional sustainable development. Using the land use data from five time points in Gansu Province from 2000 to 2020, this study analyzed the quantitative distribution, spatial patterns, and mutual transfer of land use types. The Future Land Use Simulation model was used to simulate the land use transformation under four scenarios of inertia development, urban-rural integration, planning constraints, and ecological restoration in 2035. The study found that: (1) The main land use types in Gansu Province are cultivated land, grassland, and unused land, exhibiting significant regional heterogeneity in spatial distribution. The comprehensive land use dynamics initially increased, then decreased, before increasing again. (2) Under the influence of the continuous promotion of the Western Development Strategy and the policy of returning farmland to forest and grassland, the land use transition in the Gansu Province is mainly manifested in the transfer of cultivated land to grassland and woodland, and the transfer of construction land to cultivated land and grassland. (3) Under the two scenarios of urban-rural integration and planning constraints, the results of land use simulation are reasonable, considering cultivated land protection and regional ecological environment restoration, which can meet the needs of future development. This study provides a valuable reference for land governance and spatial planning in Gansu Province.

As the fundamental terrain of deserts, sand ridges play a crucial role in shaping the surface water and thermal environment at different slope positions, which profoundly influences how biological soil crusts develop and their spatial distribution patterns. Lichen crusts are widely distributed on the desert surface. However, issues such as how lichen crusts at different slope positions affect the soil phosphorous cycle and what factors play key roles in influencing this remain unclear. Against this background, this study was conducted in Gurbantunggut Desert, involving a systematic analysis of the changes in phosphorus fractions and related enzyme activities in the lichen crust and 0-5 cm soil layer beneath the crust at different slope positions. The results showed that stable phosphorus in the soil (HCl-Pi, HHCl-Po, HHCl-Pi, and Residual-P) accounted for over 75% of the total phosphorus (TP) content, followed by medium labile phosphorus (NaOH-Pi and NaOH-Po) and labile phosphorus (Resin-P, NaHCO₃-Pi, and NaHCO₃-Po). The slope position had a significant impact on stable phosphorus, and the soil layer had a significant impact on medium labile phosphorus (P<0.05). The data on the contents of stable phosphorus, TP, organic phosphorus (Po), and inorganic phosphorus (Pi) all revealed that, in the crust layer, the values at the bottom of the slope were significantly higher than those on the east and west slopes, while in the 0-5 cm soil layer, the values on the west slope were significantly lower than those at the bottom of the slope and on the east slope (P<0.05). However, the content of NaOH-Pi was significantly higher on the east and west slopes than at the bottom of the slope in the crust layer, and it was significantly higher on the west slope than on the east slope and at the bottom of the slope in the 0-5 cm soil layer. In terms of soil enzymes, the east slope exhibited the lowest activity of alkaline phosphatase activity (ALP) and β-glucosidase activity (GC) in the crust layer, but the highest in the 0-5 cm soil layer. Random forest model analysis showed that the changes in moisture and temperature brought about by the slope position were the most important factors affecting the levels of labile phosphorus and stable phosphorus in the crust soil, respectively. This provides scientific support that enriches the theoretical framework of soil phosphorous cycling in desert ecosystems.