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.

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.

Exploring the quantitative pre assessment of the climate impact of vegetation greenness changes in the Qaidam Basin can help promote the integrated protection and systematic management of mountains, waters, forests, fields, lakes, grasses, sands, and gases. This article is based on MODIS NDVI data, meteorological data, and climate change prediction datasets. It monitors the changes in vegetation greenness with NDVI ≤ 0.3 in the Qaidam Basin from 2000 to 2023, analyzes the climate driving factors of vegetation with different greenness, and predicts the future trends of vegetation changes with different greenness. The results showed that in the past 24 years, vegetation types Ⅰ, Ⅱ, and Ⅲ in the Qaidam Basin accounted for 49.33%, 19.81%, and 30.86% of low green vegetation, respectively. Among them, the vegetation areas of S_sum, S_Ⅰ, and S_Ⅱ decreased significantly (P<0.001), while the vegetation area of S_Ⅲ increased significantly, indicating a clear improvement in vegetation quality; The cumulative effect of water and heat conditions on precipitation of low green vegetation for 2-3 years and temperature for 5 years is significantly (P<0.01) greater than that of the current year, indicating that a warm and humid climate promotes the healthy development of grasslands; Under the three emission scenarios of RCP2.6, RCP4.5, and RCP8.5 in the future, the overall trend of low green vegetation in the Qaidam Basin is decreasing, and future climate conditions are favorable for vegetation restoration and expansion. The research results can provide scientific basis for the development of ecological environment protection and desertification control measures in the Qaidam Basin.

This study investigated the community structure and function of generalized and specialized fungal species (GFS and SFS, respectively) in the soil and roots of Pinus sylvestris var. mongolica forests and their relationship with soil physicochemical properties, aiming to identify key microbial mechanisms affecting ecosystem functioning in P. sylvestris var. mongolica forests. Using high-throughput sequencing technology, we analyzed the differences in the community structure and functional groups of GFS and SFS in the soil and roots of natural forests and plantations (24 a, 35 a, 44 a) of P. sylvestris var. mongolica in the Hulunbuir Desert. The results were as follows: (1) The soil and root-associated GFS retained 169 operational taxonomic units (OTUs) in total, the soil SFS retained 603 OTUs, and the root-associated SFS retained 216 OTUs, including Tricholoma and Suillus in soil GFS; and Tricholoma, Suillus, and Cadophora in root-associated GFS; Penicillium in soil SFS; and Acephala in root-associated SFS. (2) The relative abundance of symbiotic nutritive fungi accounted for 28.49%-47.21% of soil GFS, and the dominant ecological functional group was ectomycorrhizal fungi, which showed a trend of increasing and then decreasing with forest age. Saprophytic nutritive fungi accounted for 17.01%-40.01% of soil SFS. The relative abundance of saprophytic nutritive fungi in plantation forests was lower than that in natural forests, and it showed a tendency of increasing and decreasing followed by increasing with forest age. Symbiotic trophic fungi accounted for 43.25%-54.45% of the root-associated GFS; the dominant ecological functional group was ectomycorrhizal fungi, which showed an increasing trend with increasing forest age, and the relative abundance of ectomycorrhizal fungi in natural forests was higher than that in plantation forests. (3) The soil organic matter and available phosphorus content of natural P. sylvestris var. mongolica forests were significantly higher than those of plantation forests (P<0.05). In plantation forests, with increasing forest age, the soil organic matter (SOM), total phosphorus (TP), available nitrogen (AN), and available phosphorus in the soil increased significantly (P<0.05), whereas the soil pH decreased but not significantly (P>0.05). GFS was mainly dominated by SOM, soil NH₄⁺-N, and TP (P< 0.05). Furthermore, the community variability of root-associated SFS was regulated by total nitrogen (P<0.05), whereas soil SFS was significantly affected by only TP, AN, and NO₃^--N (P<0.05). The drivers of fungal community structure showed significant ecological niche differentiation. This study contributes to a deeper understanding of the ecological functions of fungi in the soil and roots of P. sylvestris var. mongolica forests, providing a basis for the sustainable management and protection of P. sylvestris var. mongolica forests in the Hulunbuir Desert.

Global warming has resulted in the phenomenon of warming and wetting in northwest China. The Qilian Mountains is located in the arid region of northwest China, which spans the arid, semi-arid, and extremely arid climate zones from east to west. The climate has also obviously changed, which exerts a significant effect on the regional ecology and hydrological process. Based on the data of air temperature and precipitation in the Qilian Mountains and its surrounding areas from 1961 to 2022, this study analyzed the temporal and spatial variations of air temperature and precipitation in the Qilian Mountains and the relationship between precipitation and changes in precipitation with altitude. Results demonstrated a significant increase in temperature and precipitation in the Qilian Mountains in the past 60 years. The variation in temperature was the largest in the middle part of the Qilian Mountains, and the variation in precipitation was the largest in the east part of the Qilian Mountains, whereas the variation in precipitation was the smallest in the western part. The interannual variation in precipitation was the largest in August. The tendency rate of temperature increase in the Qilian Mountain area was approximately 0.36 ℃·(10a)^-1, which was higher than the national level of 0.21 ℃·(10a)^-1. The maximum temperature increase rate was observed in winter [0.45 ℃·(10a)^-1], particularly in the western region where it was 0.5 ℃·(10a)^-1. The maximum increase rate of precipitation was found in the middle region [11.86 mm·(10a)^-1]. Precipitation in the Qilian Mountains and surrounding areas increased with altitude, showing two peaks. One peak was located at an altitude of 2600-2800 m, and the other was located at an altitude of 3600-3800 m. However, the relationship between precipitation and altitude was generally unimodal for each mountain. Among the mountains, the windward slope of Daban Mountain had the largest precipitation, and Qinghai Nanshan Mountain had the smallest precipitation. The climate in the Qilian Mountains exhibited warming and humidification. The annual mean minimum temperature increased faster than the maximum temperature, and the minimum temperature increased most obviously in the western part of the Qilian Mountains. The rapid increase in the minimum temperature will exert an impact on the glaciers and ecosystems of the Qilian Mountains.

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 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.

In arid areas, farmlands are few, water-holding capacity is poor, seepage is considerable, and crop yield is low. Understanding soil moisture movement in sandy loam farmland is crucial for conserving water resources and enhancing crop yields. This study focused on the sandy loam maize farmland in the middle reaches of the Heihe River, and three experimental plots—flat film irrigation, ridge mulching irrigation, and drip irrigation under film irrigation—were set up. The HYDRUS-2D model was used to simulate the soil moisture migration process of the maize farmland under different irrigation modes. The results revealed that: (1) The simulated values of the HYDRUS-2D model agreed strongly with the measured data, with R² reaching more than 0.864 and RMSE remaining below 0.006 cm³·cm^-3, which verified the feasibility and reliability of the model in the dynamic simulation of soil moisture in sandy loam farmland. (2) Compared with the flat land mulching irrigation mode, the ridge mulching irrigation mode could increase the soil volume water content of the crops’ root zone by about 20% and reduce the seepage loss by 13.3% when the irrigation water volume was reduced by 2099 m³·hm^-2. Compared with the flat land mulching irrigation mode, the drip irrigation mode under film irrigation could reduce the irrigation water consumption by 50% and the leakage by 50.7%. (3) The drip irrigation mode under film displayed “frequent irrigation and small amount” so that the water could be more directly and efficiently replenished in the crops’ root zone, which significantly improved the soil volume water content in the root zone of maize and further reduced the seepage. The sandy loam farmland in the middle reaches of the Heihe River should be irrigated by drip irrigation under film to save water and increase yield. (4) The HYDRUS-2D model’s parameter system can also provide a reference for the dynamic simulation of irrigation water in the same type of sandy loam farmland in northern China.

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.

Plant-based sand-fixing agents are ecofriendly materials that effectively stabilize sand without polluting the soil, and their decomposition products promote plant growth. This study investigated the physical characteristics of consolidated layers formed by plant-based sand-fixing agents and their effects on soil water movement in sandy farmland using water infiltration and evaporation simulation experiments with three plant-based sand-fixing agents (Artemisia desertorum, flax, and black locust) and six application rates (0.5 g·m^-2, 1.0 g·m^-2, 2.0 g·m^-2, 3.0 g·m^-2, 4.0 g·m^-2, and 5.0 g·m^-2). Wind-sand soil sprayed with the same amount of pure water served as the control (CK). The results showed the following: (1) The soil physical properties were altered. The compressive strength of the consolidated layer was in the order of black locust >flax >Artemisia desertorum>CK. The average compressive strength of the consolidated layer treated with the three agents increased by 109.38%, 95.06%, and 58.46% compared with CK, respectively. The compressive strength of the same agent increased with concentration. Soil bulk density increased with higher application rates, with a maximum increase of 3.76% compared with CK. Meanwhile, the total porosity and saturated and minimum water-holding capacity decreased by up to 44.55%, 47.65%, and 53.62%, respectively, compared with CK. (2) The water infiltration rate was effectively reduced. The infiltration times were as follows: flax (29.53 min)≈black locust (29.52 min) >Artemisia desertorum (29.03 min) >CK (26.08 min). As the application rate increased, the infiltration time showed a U-shaped trend for black locust and flax agents, whereas Artemisia desertorum increased gradually. (3) The soil water evaporation rates were significantly reduced. For all three agents, the application rates of 2.0-4.0 g·m^-2 demonstrated the most pronounced effects. (4) Application rates of 2.0-4.0 g·m^-2 improved water retention and prevented excessively slow water infiltration. This study provides theoretical support for the exploration of new sand-fixing agents and their application in the prevention of wind erosion in sandy farmland soils.

Ammopiptanthus nanus is an endangered evergreen shrub that is endemic to the desert area of Central Asia. It exhibits strong cold and drought resistance, serves as a model species for examining the mechanisms of plant adaptation to extreme environments, and is a focus of conservation research in desert biodiversity. In this study, black and green Ammopiptanthus nanus seeds were used to study the germination and viability of newly harvested seeds and their storage by three methods. The results indicated that the germination rate of the newly harvested seeds increased with an increase in temperature, and the viability of the newly harvested seeds reached 100%. There was a significant difference in the germination of seeds with the two colors under dry-cold and -hot storage conditions, with green seeds showing significantly higher germination rates compared with black seeds (P<0.05). However, there was no significant difference in germination under wet-cold storage conditions. Wet-cold storage promoted seed germination, whereas dry-cold and -hot storage resulted in inhibition. The three storage methods had little effect on the viability of either color seed, and viability after storage was >95%. Temperature and humidity are important ecological factors that influence seed germination and viability in Ammopiptanthus nanus. The difference in seed germination represents a strategy for adapting to harsh habitats, which is conducive to increasing its survival and reproduction ability. Wet-cold storage increases the seed germination rate and maintains viability, thus providing valuable technical guidance for the conservation of germplasm resources and nursery breeding.

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.

The damaging pest Agrilus viduus Kerremans was recorded for the first time in Ili Prefecture, Xinjiang. This pest has entered the core area of wild fruit forest, where it has damaged wild apples and wild apricots. Through field surveys, fixed-point observations, and laboratory rearing, the distribution range, life history, damage characteristics, and host plants of this pest in the wild fruit forest area were preliminarily studied. This pest is distributed in Xinyuan County, Gongliu County, Huocheng County, and Tekes County and has entered the wild fruit forests of Xinyuan County, Gongliu County, and Huocheng County. In terms of its reproduction, this pest exhibits one generation per year, starts to be active in the first half of May and begins to emerge in early July, with the peak emergence period in late July. Adult insects start to lay eggs in mid-July, and the emergence process ends in early August. In early November, the second-and third-instar larvae begin to overwinter. The damage mainly takes the form of larvae boring into the phloem, cambium, and xylem of host plants. When substantial infestation occurs, death of the host can occur. This pest can damage wild apricots, wild apples, and some other economically important fruit trees in the wild fruit forest. The oviposition characteristics of this pest are rather special. Eggs are laid in clusters on the bark surface and then covered with secretions to form egg cases. The distribution of this species’ egg cases is highly correlated with the height of apricot trees, with them mainly being found at heights of 120-240 cm; the distribution of the egg cases is also related to the basal diameter, being found mainly on branches with diameters of 2-3 cm. A literature review and field investigation revealed that this insect is a pest that has been newly introduced into the wild fruit forest of Xinjiang, posing a significant threat and requiring the attention of local authorities. There is an urgent need for physical control, biological control, and chemical control methods to be applied to eradicate it in accordance with its biological characteristics.

Using MODIS snow product data, this study investigates the spatiotemporal variation characteristics of the snowmelt period over the Mongolian Plateau during the 2003-2022 hydrological years. The movement of the snowmelt line toward higher latitudes and its response to air temperature are tracked and analyzed at 15-day intervals. The results show that: (1) The proportion of snow-covered area to the total area of the Mongolian Plateau during the 2003-2022 hydrological years ranged from 55.59% to 87.61%, with the smallest snow cover in 2018 and the largest in 2009. Additionally, over the past 20 years, the snowmelt start time on the Mongolian Plateau exhibited a significant advancing trend at a rate of 0.18 days per decade (P<0.05), while the stable snow-cover area showed a delaying trend. (2) Spatially, snowmelt occurred significantly later in northern regions of the Mongolian Plateau compared to southern regions. Stable snow-cover areas were primarily concentrated in the western Mongolia and northeastern Inner Mongolia, where snowmelt times were generally later. Approximately 64.9% of these areas showed an advancing trend in snowmelt, while regions with delaying trends were mainly distributed in the northwestern part of the study area. (3) Observational analysis at half-monthly scales from January during the winter season revealed that the movement of the snowmelt line demonstrated successive synchronicity with the -5 ℃ and 0 ℃ isotherms. Correlation coefficients between snowmelt line positions and temperature, except for the year 2018 (with the least snow cover), generally fell within the higher range of 0.72 to 0.98, indicating that temperature is a key factor influencing the position of the snowmelt line.

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.

Utilizing the Google Earth Engine (GEE) cloud computing platform, the Net Primary Productivity (NPP) of Ordos was calculated based on an improved CASA model. Sen’s slope analysis and MK trend analysis methods were used to analyze the spatiotemporal changes in NPP from 2001 to 2020 and estimate the carbon sequestration capacity of Ordos City. (1) NPP in Ordos City displayed a significant seasonal variation from 2001 to 2020, with the highest values in July and August and an average annual NPP of 78.04 g C·m^-2·a^-1, following an overall fluctuating upward trend. (2) Spatially, NPP demonstrated clear heterogeneity, with higher values in the northeast and lower values in the northwest; high values were concentrated in Dalate Banner and Jungar Banner, while low values were mainly in Hanggin Banner. (3) The implementation of ecological projects and NPP changes were not fully synchronized, with a general trend of initially slow then accelerating growth; NPP change rates significantly increased after 2011 in most areas, but areas with harsher ecological conditions, such as Hanggin Banner, exhibited a lower improvement and some lag. (4) In 2011, Ordos displayed a widespread negative carbon sequestration rate. Yet, by 2020, the spatial heterogeneity in carbon sequestration had significantly increased, with higher values in the east and lower values in the west. The carbon sequestration capacity in Hanggin Banner’s western region still requires reinforcement, while Dalate Banner significantly improved its carbon sequestration capacity.

The temporal continuity and spatial equilibrium of reservoir group construction in the north slope of the Tianshan Mountain Economic Belt was verified, by extracting the water area of each reservoir from the 1990-2020 remote sensing data. The variation process of reservoir quantity and storage capacity was also analyzed by combining statistical data. The Moran index was used to quantify the aggregation degree of reservoir spatial distribution, and geographically and temporally weighted regression was established to analyze the driving factors of the reservoir. The results showed that in the past 30 years, the reservoir water area in the study region first increased by 46.25% from 1990 to 2015 and then decreased by 1.63% from 2015 to 2020. The number of reservoirs and storage capacity enhanced by 64.94% and 71.06% respectively. From 1990 to 2020, the Moreland index of the reservoirs in each representative year was 0.81, 0.83, 0.79, 0.91, 0.66, 0.73, and 0.78, respectively, along with a positive correlation between the spatial distribution of the reservoirs. The high-value area of reservoir distribution was mainly concentrated in the agricultural irrigation region of the Kuitun River Basin, and the low-value area in the industrial region was represented by Urumqi City. The main factors affecting the variation in reservoir capacity were evaporation, rainfall, elevation, population, and GDP. Evaporation adversely affected storage capacity, and the effect of rainfall was not uniform in space. Altitude and population had a positive impact on the construction of the reservoir in the west section and a negative influence in the east section. The GDP had a positive association with reservoir construction in the eastern section and a part of the western section, but a negative correlation in the middle section. These results can provide a reference for reservoir planning, construction, and operation management in similar areas.

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.

Explore the dominant environmental factors affecting the distribution of Hippophae rhamnoides subsp. sinensis and simulate its potential suitable distribution areas, to provide a theoretical basis for the cultivation, conservation, and development of its wild resources. Methods: The working characteristic curve and the area under the curve of the subject were used to evaluate the accuracy of the model. The dominant environmental factors were screened by comprehensive contribution rate and the knife cutting method and their suitable range were determined; The MaxEnt model was applied to simulate and predict the suitable (growth) areas and their dynamic changes under current and future climatic conditions. Results: (1) The model accuracy was high (AUC=0.953), which can effectively simulate the potential distribution of H. rhamnoides subsp. sinensis. (2) Annual precipitation (325-650 mm), altitude (1200-3850 m), the average temperature during the coldest season (-7.25-1.25 ℃), and precipitation in the driest month (1-4 mm) were the leading environmental factors affecting its distribution. (3) It was mainly concentrated in Gansu, Qinghai, Sichuan, Xizang, Ningxia, Shaanxi, Shanxi, Henan, Hebei, and Inner Mongolia with sporadic occurrences in Yunnan and Guizhou; future climate change will not only force its expansion to the northwest high latitude, high-altitude area, and the Yunnan-Guizhou plateau but also remarkably shrunk the southeast low latitude and low altitude distribution area; the overall distribution area increased. Altitude and hydrothermal conditions were the leading factors affecting the distribution of H. rhamnoides subsp. sinensis. To cope with future climate change, the focus of its industry should be shifted to the northwest, middle, and high-altitude areas, and the reasonable development and utilization of its resources should be carried out to achieve sustainable development.

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.

In recent years, many studies on sand and dust storms in Northwest China have mainly focused on large and regional scales, with less research on urban sand and dust storms. This paper studies the changing characteristics of urban sand and dust weather in Lanzhou City to understand the alteration characteristics of urban sand and dust storms. The results showed that (1) The number of days of floating dust, sand lifting, and dust storms in Lanzhou City from 2009 to 2023 showed multisegment fluctuation; the change at the time series level as a whole and the total number of days of sand and dust weather showed a marginal decrease of 0.66 d·a^-1. (2) The sand and dust weather in Lanzhou City was concentrated in the spring, declining monthly after the cliff rises in March, mainly dominated by floating dust, followed by sand and dust storms. (3) The annual average frequency of dusty weather in Lanzhou City from 2009 to 2023 correlated positively with wind speed, which is the main meteorological factor affecting dusty weather, weakly negatively correlated with relative humidity, and no obvious correlation with the rest of the meteorological factors. (4) The number of dusty days occurred in 3-time cycle scales of 2~3 a, 4~7 a, and 8~23 a, revealing a multisegmented nonsignificant fluctuation, of which 8~23 a corresponded to two peaks with the most substantial amplitude, which is the primary cycle of dusty fluctuation.

Soil multifunctionality is a vital component of ecosystem multifunctionality. Exploring the multifunctionality of soil in the Picea schrenkiana plantation at various ages offers valuable insights into soil capabilities. This research should enhance our understanding and support the management of vibrant forest ecosystems, making a significant contribution to environmental science. This study investigated the Picea schrenkiana plantation at the ages of 30, 40, 50, and 60 years, focusing on 15 indicators related to soil carbon, nitrogen, and phosphorus, to evaluate the soil multifunctionality of the Picea schrenkiana plantation. The findings reveal the following: (1) Soil moisture content, total nitrogen, and available nitrogen initially decreased before increasing with forest age, while daily average temperature and organic matter content exhibited a consistent decline with increasing forest age. (2) The activity of soil urease displayed an inverted “N” shaped trend concerning forest age, whereas the activities of cellulase and invertase initially rose and then declined. Catalase activity gradually decreased with increasing forest age. (3) Soil multifunctionality increased and then decreased with aging of the forest. The main factors affecting soil multifunctionality included the available nitrogen and urease. Therefore, forest age is a significant ecological factor that influences soil multifunctionality of the Picea schrenkiana plantation. In addition, managing related factors such as soil physical and chemical properties and enzyme activity is crucial. These research findings are significant for the sustainable management of Picea schrenkiana plantation on the northern slopes of Tianshan Mountains in Xinjiang.

This study used GRACE and GRACE-FO gravity satellite data to invert the Terrestrial Water Storage reserves in the Yellow River Basin from 2002 to 2022. We also calculated the standardized Water Storage Deficit Index to analyze the drought characteristics of the Yellow River Basin from 2002 to 2022. From 2002 to 2022, the Terrestrial Water Storage in the entire Yellow River Basin, upstream, and middle lower reaches was about 5.43 mm·a^-1, 1.03 mm·a^-1, and 8.36 mm·a^-1, respectively. Between 2002 and 2022, six drought events occurred in the entire Yellow River Basin, eleven in the upper reaches and eight in the middle and lower reaches. Regarding the drought intensity, moderate and extreme droughts were more common in the upper reaches of the Yellow River, mild drought was more common in the middle and lower reaches, and mild drought was more common in the entire region, with the strongest event being severe drought. The drought events in the Yellow River Basin in 2022 were concentrated at the junction of the upper and middle lower reaches. Drought events mainly occurred in the upper reaches of the Yellow River Basin; the area is in a drought state throughout the year, except for the Yellow River source area. The drought phenomenon is evident in the Inland River Basin and Fen River Basin at the junction of the middle and lower reaches of the Yellow River Basin; only a few months in the lower reaches of the Yellow River Basin are affected by drought. In 2022, the center of the drought events gradually shifted from the Qiantao Basin to the Xitao Basin.

In this study, three typical sand-fixing plants in the desert-oasis transition zone were used as the research objects. To simulate water infiltration of 10 L, 15 L, and 20 L, respectively (simulating light rain, moderate rain, and heavy rain), the field staining tracer method and computer image processing technology were used. The distribution rules and characteristic parameters of the priority flow in the vertical and horizontal sections of the dyed images were analyzed, and the characteristic parameters were selected as evaluation indexes. The mean square decision method was used to determine the degree of development of the soil priority flow in the root zone of typical sand-fixation plants, which provided a reference for the restoration of sand-fixation vegetation and effective utilization of water resources in the desert-oasis transition zone. The results showed that (1) Soil preferential flow occurred in the root zone of sand-fixing plants in the desert-oasis transition zone, and the main types were funnel flow and finger flow. When infiltration water water was increased, the preferential flow occurred laterally. (2) Under the various conditions of water infiltration, the soil staining area ratio in the root zone of the three sand-fixing plants showed a nonlinear decrease with an increase in soil depth. The curve of the soil staining area ratio in the root zone of Haloxylon sacralis and Jujube sacralis showed an “S” shape, and the water infiltration was non-uniform. (3) The priority flow evaluation index P_FI was from large to small: Haloxell (0.685), Sphaerophora sphaerophora (0.543), and Hippophora hippophobia (0.502). The degree of priority flow development of the soil in the root zone was the highest.

Land resources are the most fundamental production factors for human survival and development. Investigating the driving factors of land use change and simulating future land use scenarios are of great significance for regional sustainable development. Taking the Gansu section in the Yellow River Basin as the research area, this paper, based on multi-source data, employs methods such as the land use transfer matrix, GeoDetector, and the Mixed-cell Cellular Automata (MCCA) model to reveal the evolution characteristics of land use and conduct multi-scenario simulations for 2035. The results are as follows: (1) From 2000-2020, the land use/cover in the research area mainly comprised cultivated land, forest land, and grassland. The extent of forest and grassland cover was relatively high, and the area of cultivated land decreased significantly. Moreover, the conversion between cultivated land and grassland was the most obvious. (2) The dominant factors influencing land use change of the Gansu section in the Yellow River Basin include elevation, temperature, precipitation, distance from rural settlements, and population density. The q-values of the interaction effects of all driving factors have increased. (3) The MCCA model exhibits high simulation accuracy, with an overall accuracy of 0.903. In 2035, the simulation results vary among scenarios. Under the natural evolution scenario, cultivated land and unused land contract, while other land types expand. Under the cultivated land protection scenario, the current stock of cultivated land is maintained, but the area of grassland decreases significantly. In the ecological priority scenario, the areas of forest land and grassland increase significantly. The economic development scenario is manifested in a more aggressive development paradigm, under which construction land experiences a remarkable expansion. The research results provide references for land management and high-quality development of the Gansu section in the Yellow River Basin.

In this study, we aimed to investigate the chemical characteristics of groundwater in farmland within Hetao Irrigation District, focusing on deep water conservation and the relationship between water and salt migration among various types of farmland. Typical irrigated farmland in Hetao Irrigation District was selected as the study area, and an analysis was conducted on shallow groundwater ions and changes in groundwater levels using classical statistics, principal component analysis, and the principle of solute dynamics. The main factors affecting groundwater quality were identified, and the changes in soil ions before and after crop cultivation were examined. Furthermore, the contribution of groundwater to salt accumulation across different types of farmland was quantified, and a water-salt equilibrium model was developed using the locational flux method. The results revealed the following: (1) Shallow groundwater cations were dominated by Na⁺+K⁺, constituting 53.22% of total cations, while anions were dominated by SO₄^2-, making up 41.04% of total anions; thus, the principal chemical type of groundwater was classified as HCO₃·SO₄-Na, with key factors affecting groundwater quality identified as Total Dissolved Solids (TDS), Na⁺+K⁺, HCO₃^-, and SO₄^2- through principal component analysis. (2) Salt accumulation before and after crop cultivation was mainly comprised of NaCl and Na₂SO₄. (3) Evapotranspiration (ET) varied across different types of fields, with measurements of 422.6 mm for wasteland, 475.6 mm for sunflower fields, and 625.8 mm for maize fields. (4) Maize, sunflower, and wasteland soils exhibited salt accumulation, with horizontal infiltration contributing 1924 kg·hm^-2 of salt to wasteland, accounting for 22.00% of total salt accumulation. (5) There is a salt transition zone between wasteland and arable land, indicating the planting of salt-tolerant cash crops, such as sunflower, near wasteland to mitigate crop yield reductions due to high salinity levels. This study offers valuable insights into the efficient use of local water resources, soil salinity management, and sustainable agricultural development.

Invasive plants have significantly impacted the function and biodiversity of the global ecosystem. In the context of global climate change, the effective control of invasive plants is important for maintaining the stability of grassland ecosystems. The spectral differences between invasive plants and native dominant species during phenological stages provide an opportunity for remote sensing technology to monitor their spatiotemporal distribution. Previous studies have primarily focused on single-phase monitoring and the classification of plants, with relatively fewer studies on multitemporal continuous monitoring, particularly during early phenological stages. In this study, we focused on Pedicularis kansuensis, an invasive species of the Bayinbuluk grassland of Xinjiang, using UAV-based multispectral data and machine learning algorithms to extract spatial distribution data for P. kansuensis during key phenological stages in 2023 (emergence, initial flowering, peak flowering, and senescence stages) and the peak flowering stage in 2024. We examined the feasibility of extracting P. kansuensis at each phenological stage and analyzed changes in inter-annual spatial distribution. The results indicated that (1) The random forest algorithm slightly outperformed the support vector machine, with model accuracy varying with the growth stages of P. kansuensis; specifically, peak flowering stage (late July to late August) > initial flowering stage (late June to early July) > emergence stage (mid-June) > senescence stage (mid-September). Throughout the growth season, spatial distribution during the early growth stages (emergence and initial flowering) exhibited a high spatial overlap with the peak flowering stage, and the key features were consistent with those of the peak flowering stage. This suggests that the random forest algorithm can effectively map the distribution of P. kansuensis during the emergence stage, which provides important technical support for the early-stage monitoring of invasive plants; (2) The spatial distribution of P. kansuensis exhibited significant inter-annual variation, with less than 15% spatial overlap between the two years; (3) During the growth season, the most important feature for distinguishing P. kansuensis (excluding the senescence stage), from other co-occurring species was the normalized difference index, calculated from the 555 nm and 720 nm bands, followed by the green band. Because P. kansuensis had entered the senescence stage, there was a noticeable change in feature importance, with significant differences in various background environments. These results demonstrate the feasibility of using UAV-based multispectral remote sensing technology for monitoring the early phenological stages of P. kansuensis and offer technical support for early warning and control measures.

Malus sieversii, a state-protected species and the progenitor of cultivated apples, is an important germplasm resource within the genus Malus. In this study, we aimed to compare the structural characteristics of chloroplast genomes across various populations of M. sieversii, clarify the lineage divergence pattern, and trace the evolutionary history of this species. We used the Illumina NovaSeq platform to conduct whole-genome sequencing of individuals from 16 different populations, with one sample representing each population. After conducting quality control on the sequencing data, we conducted genome assembly and functional annotation. Subsequently, we conducted a comprehensive structural analysis and lineage differentiation studies on the assembled genomes. The chloroplast genome length in M. sieversii ranged from 160195 to 160279 base pairs (bp), exhibiting a typical tetrad structure. In total, 131 genes were identified within the chloroplast genome, along with 48-58 long repeats and 93-101 simple sequence repeats. Notably, variations in the IR region between M. sieversii and other species in the genus were minimal, predominantly occurring in noncoding regions. Phylogenetic analysis revealed that M. sieversii clusters into three distinct lineages: lineage I, primarily occupying the eastern part of the distribution range, and lineages II and III, predominantly found in the west. The divergence time between lineages I and II was approximately 1.74 million years ago (Ma), while the divergence between lineages I, II, and III was around 2.28 Ma. These findings indicate that the lineage divergences of M. sieversii were significantly influenced by climate changes during the Quaternary period. Compared to internationally distributed populations, M. sieversii in China shows relatively low genetic diversity. Therefore, tailored conservation strategies should be implemented for M. sieversii across different regions, with particular emphasis on protecting genetically diverse populations in the Tacheng area.

Ningxia as the only province whose entire territory is included in the “Three-North project,” has an extremely important ecological location. This study investigated the temporal-spatial variation in the normalized difference vegetation index (NDVI) and quantified the impact of climate variations (CV) and human activities (HA) on NDVI based on various datasets (e.g., NDVI and meteorological dataset) and methods(e.g., trend analysis and residual trend analysis). The trend of future NDVI in the Ningxia was also determined using the Hurst index. Results demonstrated that (1) NDVI fluctuated, showing an increase at a rate of 7.6×10^-3 a^-1 during the study period. The spatial distribution of NDVI was heterogeneous, showing the characteristics of “Yellow River diversion irrigation area and southern mountainous area high and central-arid zone low.” NDVI in the Ningxia generally belonged to low-level vegetation cover (0.2<NDVI≤0.4) with a proportion of >50%. (2) NDVI exhibited an overall increasing trend across 94.94% of the total Ningxia from 2001 to 2020. Furthermore, 65.23% of vegetation of the study area in the future may be at potential risk of degradation. (3) Both CV and HA exerted a positive effect on the amelioration of NDVI, and increases in NDVI in 89.49% of the total Ningxia were controlled by the interactive effect of CV and HA. Among the climate factors, precipitation played a major role in promoting the change of NDVI. (4) The relative contribution rates of CV and HA to changes in NDVI were 43.79% and 56.21%, respectively. Overall, in future programs on vegetation restoration and ecological construction, the primary role of human activities in increasing vegetation cover should be actively exploited, and monitoring and management of the existing vegetation should be strengthened to avoid its degradation trend.

In this study, we examined seven species suited to desert grasslands and analyzed the relationship between soil nutrients and nitrogen cycling in natural and artificial vegetation through field sampling and laboratory analysis. The results showed the following: (1) Salsola collina and Caragana korshinskii howed high nutrient content, which had a fixed effect on nutrients and was conducive to the restoration of nutrient content within the study area. Additionally, these species significantly increased the abundance of bac, AOA, AOB, nirS, nirK, nifH, and nosZ genes in the rhizosphere soil. (2) The abundance of the nifH gene was significantly correlated with soil nutrient levels. (3) The ecological restoration of soil in the study area is influenced by the combined effects of carbon and nitrogen, necessitating adjustments to the fertilization structure and improvements to the soil environment in the future. Overall, natural vegetation, such as Salsola collina, and artificial vegetation, such as Caragana korshinskii, outperformed other species in soil nutrient fixation and nitrogen cycling functional gene abundance, making them ideal for restoration in the study area. These findings provides valuable insights for selecting plant species in future ecological restoration of gravel-sand-mulched fields.

In this study, 63 samples comprising atmospheric precipitation, river water, groundwater, lake surface brine, and intercrystaline bittern were collected from the Nalenggele River. These samples were analyzed to assess the distribution characteristics and influencing factors of hydrogen and oxygen isotope, as well as deuterium surplus. The key findings are as follows: (1) The δD and δ¹⁸O values of atmospheric precipitation in the study area are higher than the average values across China. Due to the combined effect of evaporation and water vapor recirculation, the slope of the meteoric water line in the study area is lower than the global meteoric water line but higher than that of other drainage basins in the northwest arid zone. The East Asian monsoon, which transports water vapor over long distances, is the primary factor contributing to the low deuterium surplus in the atmospheric precipitation of the study area in August. (2) The river water line slope in the study area is smaller than that of the global meteoric water line. The deuterium surplus in river water is negatively correlated with δ¹⁸O and TDS (Total dissolved solids), which is attributed to isotopic fractionation caused by evaporation. The river is primarily recharged by atmospheric precipitation from southern mountainous areas. Variations in isotopic elevation effects result in differences in δD and δ¹⁸O values across different sections of the Nalenggele River. (3) Groundwater-surface water interactions, along with the groundwater recharge from multiple sources in the southern mountainous areas, cause the slope and intercept of the groundwater lines to be larger than those of both the global and local meteoric water lines. (4) The hydrogen and oxygen isotopes of surface brine and intercrystaline brine show an “oxygen drift” phenomenon, with deuterium surplus values falling below zero. This is attributed to excessive fractionation induced by evaporation. The deuterium surplus value in intercrystaline is lower than that of surface brine, likely due to the dissolution and filtration of salt minerals.

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.

To address the imbalance between the supply and demand of water resources and compensate for the shortage of freshwater resources, the use of brackish and saline water for irrigation has become crucial. Simultaneously, the effects of different sodium adsorption ratios (SAR) on cotton growth and yield can vary under the same degree of mineralization in irrigation water. Therefore, to further explore the effects of irrigation water mineralization and SAR on cotton, we established three mineralization treatments at 3 g·L^-1(T3), 5 g·L^-1(T5), and 7 g·L^-1(T7). Additionally, we designed three SAR treatments at 10 (mmol·L)^1/2(S10), 15 (mmol·L)^1/2(S15), and 20 (mmol·L)^1/2(S20). Local freshwater irrigation served as a control (CK). In total, 10 treatments were conducted in this experiment to examine the combined effects of irrigation water mineralization and SAR costress on soil salinity, cotton growth, plant ion accumulation, yield, and water use efficiency. The results indicated that soil salinity increased with higher irrigation water mineralization or SAR, initially rising before decreasing with increasing soil depth. Plant Na⁺ content increased with increasing irrigation water mineralization or SAR, with the interaction effect between these factors being highly significant. Conversely, plant K⁺, K⁺/Na⁺, and N content decreased as irrigation water mineralization or SAR increased. Additionally, plant height, stem thickness, leaf area index, and dry matter mass all showed a significant decreasing trend with increased irrigation water mineralization and SAR, with significant inhibition of dry matter accumulation observed. Irrigation water mineralization and SAR significantly affected the number of bolls per plant, boll weight, seed cotton yield, and water consumption (ET). Moreover, irrigation water SAR significantly affected water use efficiency (WUE). Compared to the CK treatment, yield and WUE increased by 3.27% and 1.09% in T3S10, 2.54% and 0.47% in T5S10, and 1.18% in T3S15, respectively. This increase indicated that moderately reducing the irrigation water SAR can help mitigate yield reduction in cotton due to increased mineralization. Different levels of mineralization and SAR in irrigation water increased the Na⁺ content in cotton plants while reduced K⁺ and N nutrient uptake, and increased the K⁺/Na⁺ ratio. Consequently, cotton plant height, stem thickness, leaf area, and dry matter accumulation gradually decreased as irrigation water mineralization or SAR increased. The number of bolls per plant and boll weight increased in the T3S10, T3S15, and T5S10 treatments compared to the CK treatment. In conclusion, using brackish water with an irrigation water mineralization of 3 g·L^-1 and SAR below 15 (mmol·L^-1)^1/2, or an irrigation water mineralization of 5 g·L^-1 with SAR below 10 (mmol·L^-1)^1/2, can ensure cotton yield. These findings provide a theoretical basis and reference for the efficient use of brackish water in Xinjiang and other extreme arid regions.

Ecological restoration is a major project to implement China’s ecological civilization construction. Delineating zoning units is a prerequisite and an essential foundation for the differentiated implementation of land remediation and ecological restoration; it holds significant theoretical and guiding value for formulating differentiated restoration measures. Taking the Shanxi section of the Yellow River Basin as an example, this study introduces the GeoSOM (Geographic Self-Organizing Map) algorithm to perform spatial clustering for ecological restoration in the study area based on grid units. The Dunn index evaluated the effectiveness of the clustering and selected the optimal scheme. Finally, the Support Vector Machine (SVM) identified the boundaries of the ecological restoration zones, resulting in the delineation of the ecological restoration areas. The results indicate that, after the GeoSOM network spatial clustering, the study area was divided into four major categories according to the Dunn index evaluation, with each category exhibiting significant spatial differentiation characteristics. Based on the clustering results, the SVM identified ten ecological restoration zones, and ecological restoration strategies were proposed for each zone. This study improves the traditional SOM network, which emphasizes thematic attributes, by using the GeoSOM algorithm that measures the similarity of thematic and spatial attributes, making it more suitable for spatial clustering. The findings provide a new reference for methods of ecological restoration zoning.

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.

In this study, we investigated the spatiotemporal changes in vegetation greenness on the southern slopes of the Qilian Mountains and their responses to climate change and human activities. Utilizing the Google Earth Engine platform, we applied algorithms and remote sensing technologies to analyze these changes. By employing Sen’s trend analysis, the coefficient of variation, the Hurst index, ArcGIS spatial analysis, and multiple residual regression methods, we integrated multisource data products to comprehensively analyze the characteristics of vegetation greenness changes. Additionally, we assessed future trends and stability while thoroughly examining the influences of climate change and human activities. The results indicated the following: (1) From 2001 to 2020, vegetation greenness on the southern slope of the Qilian Mountains exhibited an overall upward trend, accompanied by significant spatial variations. Stability analysis revealed that the coefficient of variation ranged from 0 to 0.84, with a mean of 0.09, indicating that changes in vegetation greenness remained relatively stable and exhibited a positive trend. (2) Regarding influencing factors, both precipitation and temperature exhibited a positive correlation with vegetation greenness, with temperature showing a more pronounced effect. Notably, 95.7% of the study area passed the significance test, highlighting that temperature primarily drives changes in vegetation greenness. (3) Human activities have positively influenced changes in vegetation greenness. Overall, these changes result from the combined effects of climate change and human activities, with relative contribution rates of 36.68% for climate change and 63.32% for human activities. The higher contribution rate of human activities is closely linked to the implementation of ecological engineering initiatives.

The Yellow River Basin is an important ecologically fragile area in China. The clarification of the relationship between different levels of precipitation, precipitation days, and precipitation intensity in the basin is important to characterize the precipitation patterns in the basin. Using precipitation data collected from 96 meteorological stations in the Yellow River Basin from 1960 to 2020, the spatial and temporal variation characteristics of different grades of precipitation in the basin were analyzed using mathematical statistics and Pearson correlation analysis, and the contribution and impact of different grades of precipitation on the total precipitation were discussed. In the studied recent 61-year period, the annual precipitation and precipitation intensity in the Yellow River Basin followed increasing trends with rates of 0.008 mm·(10a)^-1 and 0.12 mm·d^-1·(10a)^-1, respectively. The number of precipitation days followed a decreasing trend with a rate of -1.82 d·(10a)^-1. The rainfall and days of light rain and moderate rain followed a downward trend; the amount and number of days of heavy rain, rainstorm, and heavy rainstorm followed an upward trend, and the precipitation intensity of each grade followed an increasing trend. Over the recent 61-year studied period, the highest occurrence rate of light rain was 84.32%, with the highest contribution rate from light rain (37.64%) followed by moderate rain (34.47%). The occurrence rate and contribution rate of light rain followed decreasing trends, whereas the occurrence rate and contribution rate of precipitation of heavy rain followed increasing trends. The areas with high values of light precipitation, light precipitation days, and light precipitation intensity were mainly concentrated in the southwest of the basin. As the precipitation level increased, the areas with high precipitation, precipitation days, and precipitation intensity were mainly concentrated in the southeast of the basin. Correlation analysis revealed that the annual precipitation of the Yellow River Basin was strongly affected by moderate and heavy rainfall, the annual precipitation days were strongly affected by the light rain days, and the annual precipitation intensity was strongly affected by the amount of heavy rain, rainstorm, and precipitation days. These findings can support ecological protection in the basin.

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.

Due to the frequent occurrence of drought events in Ordos, the local economic development has been seriously affected. Therefore, it is necessary to study the temporal and spatial evolution characteristics of droughts. This study used the monthly precipitation data of 85 grid points in Ordos from 1961 to 2020. It analyzed the applicability of the Standardized Precipitation Index and Precipitation Anomaly Percentage in the region by using the run theory. It further examined the temporal and spatial evolution characteristics of drought by inverse distance interpolation. The conclusions were (1) The Pa index had strong sensitivity and accuracy for drought description. (2) The interannual variation of drought was characterized by high frequency, low intensity, and robust continuity. In terms of seasonal changes, the frequency of summer drought was the highest, reaching 16.7%, and that of winter drought was the lowest, at only 13.3%; the drought incidence gradually decreased with an increase in the drought level. (3) The western part of the study area was more prone to enhanced drought levels than the eastern part. Simultaneously, the probability of being unaffected by drought has gently elevated from 42% to 75%. (4) The drought situation in the spring and summer impacted the annual drought situation the most; the situation in autumn and winter improved, more obviously in winter.

In this study, we assess the characteristic bias in the diurnal precipitation forecasts from two models—CMA-SH9 and CMA-MESO—for hourly precipitation forecasts across four subregions in the Hedong Region of Gansu Province (the Gannan Plateau and the Longnan, Longdong, and Longzhong regions). These forecasts were assessed based on rainfall amount and frequency, using observed hourly precipitation data from 20 storm rainy days between May and September 2019-2021 in the same region. The results show the following: (1) Both models have similar forecasting abilities for precipitation amounts of ≥2.5 mm·h^-1 and ≥5 mm·h^-1 in the Gannan Plateau and the Longnan and Longdong regions. However, the CMA-MESO model facilitates easier precipitation forecasts of ≥5 mm·h^-1 in the Longzhong region than the CMA-SH9 model. (2) For rainfall ≥2.5 mm·h^-1, both models overestimate intensity during the day and underestimate it at night compared to observations, with significant deviations mostly occurring around the peak time of observed rainfall at night. The CMA-SH9 model generally outperforms the CMA-MESO model in predicting rainfall intensity in the Longzhong and Longdong regions most times of the day. In the Longnan region, the CMA-SH9 model performs better than the CMA-MESO model in predicting rainfall intensity at night but performs worse during the day. For rainfall ≥5 mm·h^-1, the CMA-SH9 model consistently predicts rainfall intensity better than the CMA-MESO model in the Longnan and Longdong regions, but worse in the Gannan Plateau, most of the time. (3) For rainfall ≥2.5 mm·h^-1, both models predict higher rainfall frequency during the day and lower frequency at night compared to observations, with significant deviations mostly occurring around the peak time of observed rainfall at night. The CMA-SH9 model mostly outperforms the CMA-MESO model in predicting rainfall frequency. For rainfall ≥5 mm·h^-1, both models underestimate rainfall frequency compared to observations in the Longnan, Longzhong, and Longdong regions, with the negative forecast deviation more pronounced around the peak time of observed rainfall at night. (4) Phase error are predominant across the four subregions for both models, while amplitude error was minimal.