The Hexi region is highly vulnerable to ecological degradation, but quantitative assessments of its ecological sensitivity remain limited. This study developed an integrated assessment framework that combines an Albedo-normalized difference vegetation index (NDVI) feature space desertification index with ecological indicators, and analyzed spatio-temporal patterns and drivers of variation in the Hexi region, China during 2003-2020 using analytic hierarchy process (AHP)-entropy weighting and Geographical detector. Ecological sensitivity showed a clear west-east gradient, with highly sensitive areas concentrated in the northern deserts and the southern Qilian Mountains. The average sensitivity increased from 0.4838 in 2003 to 0.5169 in 2020, with a temporary decline to 0.4891 in 2015 due to reduced desertification sensitivity (DS). Habitat sensitivity (HS; q=0.376) and DS (q=0.321) were the dominant drivers, and the interaction between DS and terrain produced the strongest effect (q=0.757). During 2003-2020, barren land decreased by 3.38%, while cropland and grassland increased by 13.76% and 7.21%, respectively. However, rising ecological sensitivity indicates persistent vulnerability despite land-cover improvement. These findings support ecological conservation and sustainable land management in arid regions.

Under global climate change, limited research on the spatial and temporal variability and influencing factors of climatic water availability (CWA) constrains assessment of surface water surplus or deficit driven by climate. This study used an explanatory framework that integrated the Optimal Parameter Geographic Detector (OPGD) with the eXtreme Gradient Boosting-SHapley Additive exPlanations (XGBoost-SHAP) model to explore the spatiotemporal variability of CWA and the model-based explanatory variables across the Pamir Plateau from 1960 to 2020. Results showed that CWA exhibited significant spatial heterogeneity, with higher availability in the western part of the plateau and lower values in the eastern part. OPGD results highlighted soil moisture (SM) and snow water equivalent (SWE) as dominant explanatory variables of spatial heterogeneity, with terrain and human factors exerting weaker effects. XGBoost-SHAP results further identified SWE (58.00%) and SM (22.20%) as the two most important explanatory variables, while the maximum temperature (T_max), vapor pressure deficit (VPD), and solar radiation (SRAD) combined accounted for only 11.60%. These findings advance the understanding of complex mountain hydrology by quantifying the relative importance of coupled meteorological and topographic drivers. The identification of SWE and SM as dominant explanatory variables highlights the crucial role of cryospheric and soil hydrological processes in regulating water availability across the Pamir Plateau, offering new insights into regional water resource management under climate change.

Farmland ecosystems within the oasis-desert ecotone of arid regions play a crucial role in sustaining regional ecological stability and environmental functioning. However, the spatial distribution patterns of ecosystem multifunctionality (EMF) and the key factors associated with its variation across different crop types and habitat zones remain inadequately understood. This study investigated jujube orchards and cotton fields across two contrasting habitat zones, namely the oasis core and the oasis-desert transition zone, in the Alar region of southern Xinjiang Uygur Autonomous Region, China, during the growing season from June to September 2024. Eight ecosystem functional indicators, including three soil nutrient pools, soil water-holding capacity, three herbaceous α-diversity indices, and dust retention per unit leaf area, were quantified and standardized to calculate EMF and subsequently integrated into five ecosystem functional dimensions representing carbon sequestration, nutrient cycling, water storage, plant diversity, and air purification. An integrated analytical framework combining random forest analysis, two-stage partial least squares structural equation modeling (PLS-SEM), and trade-off-synergy analysis was employed to identify dominant predictors associated with EMF, clarify potential pathways linking habitat zone and crop type to EMF, and characterize functional interactions across different habitat zone-crop type systems. Along the gradient from the oasis core to the oasis-desert transition zone, soil organic carbon, total nitrogen, and total phosphorus stocks in both jujube and cotton systems declined by 14.8%-37.2%, 25.0%-51.0%, and 16.9%-24.9%, respectively. Soil water-holding capacity also decreased by 5.3-20.8 mm, whereas dust retention per unit leaf area increased markedly by 16.0%-73.0%. Accordingly, EMF was approximately 10.0% lower in the oasis-desert transition zone than in the oasis core, but remained consistently higher in jujube orchards than in cotton fields within the same habitat zone. Random forest analysis and two-stage PLS-SEM consistently showed that habitat zone regulates EMF primarily through a soil fertility-biodiversity pathway, whereas crop type exerted a weaker effect mainly through soil water dynamics. Trade-off-synergy analysis revealed predominantly synergistic functional relationships in the oasis core, with all pairwise relationships among the five ecosystem functional dimensions in oasis-core cotton fields exhibiting synergy. In contrast, air purification in oasis-core jujube orchards showed clear trade-offs with the other four functional dimensions. Trade-offs became more frequent and pronounced in the oasis-desert transition zone, particularly in transition-zone cotton fields, where reductions in carbon sequestration and water storage are accompanied by enhancements in plant diversity, nutrient cycling, or air purification. Overall, this study elucidates the mechanistic basis of EMF decline and the intensification of functional trade-offs under conditions of farmland marginalization in oasis-desert ecotones. These results provide important scientific support for zone-specific management strategies that emphasize multifunctional co-benefit optimization in the oasis core, while prioritizing the conservation of carbon sequestration and water storage functions in environmentally vulnerable oasis-desert transition zones.

Intelligent and high-precision monitoring of soil salinization is critical for effective soil environmental management and for protecting and improving farmland quality. This study is focused on the ecologically fragile lower reaches of the Shiyang River Basin, China and involves the use of multisource remote sensing data and weakly supervised semantic segmentation to monitor changes in soil salinization from 2017 to 2023. By integrating spatial autocorrelation analysis, geographic detectors, and a coupling coordination degree model, we systematically examined the scale-dependent aggregation effects, key driving factors, and ecological impacts that have arisen since the implementation of environmental interventions. The results reveal that salinization exhibited interannual stability but significant seasonal variation over time. Spatially, this process displayed a pattern characterized by "low-salinity core oases surrounded by high-salinity peripheries". Temperature change and groundwater depth were identified as the primary drivers, whereas interactions among other factors, such as evaporation, demonstrated synergistic enhancement effects. Furthermore, coupling coordination analysis revealed improved coordination between the soil and vegetation systems, indicating that ecological restoration measures effectively reduce the risk of ecosystem degradation. This study provides technical support for the precise management of soil salinization in arid regions and important scientific evidence for ecological restoration and decision-making strategies.

In the Hexi Corridor of Northwest China, oasis-irrigated agriculture depends on intensive water and fertilizer inputs to attain high yields. However, the synergy between resource efficiency and environmental sustainability remains unclear. Based on a two-year (2021-2022) field experiment in the arid irrigation areas of Hexi Corridor, this study evaluated four management practices for spring wheat systems: conventional practice (CP), optimized practice (OP), OP with nitrification inhibitor (OP-NI), and OP with slow-release fertilizer (OP-SRF). To identify the optimal strategies, we assessed their effects on carbon and nitrogen footprints, energy balances, and economic benefits using life cycle assessment (LCA), energy balance analysis, and economic calculation methods. Among the four treatments, two-year average cumulative soil direct greenhouse gas (GHG) emissions ranged from 7118.7 to 8353.6 kg CO₂-eq/hm². The GHG emissions from agricultural management ranged from 6823.0 to 7904.4 kg CO₂-eq/hm². Compared to CP, OP-NI and OP-SRF treatments significantly reduced the carbon footprint per unit area (by 232.9% and 267.4%, respectively) and the nitrogen footprint per unit area (by 32.5% and 35.5%, respectively), while improving energy use efficiency (by 35.7% and 39.0%, respectively). The OP-NI treatment achieved the highest economic returns, which was 18.4% higher than the OP-SRF treatment over the two-year average. The multi-dimensional trade-off analysis based on Z-score showed CP treatment with the lowest total score (-20.92) and OP-NI treatment with the highest (9.62). The OP-NI treatment was proven to be the optimal management strategy for spring wheat production in the arid irrigation areas of Hexi Corridor. It can maintain crop yield, enhance energy efficiency, and improve economic returns, while reducing carbon and nitrogen footprints, thereby promoting sustainable agriculture. This study provides a scientific basis and practical reference for sustainable, low-carbon wheat production in arid irrigation regions of Northwest China.

Arid ecosystems occupy approximately 41% of the Earth's land surface and play crucial roles in global carbon (C) sequestration and biodiversity maintenance. However, extreme water limitation and nutrient scarcity in these regions pose significant challenges to plant growth and ecosystem functioning. This study characterized the spatial patterns of leaf C, nitrogen (N), and phosphorus (P) concentrations and their stoichiometric ratios (C:N, C:P, and N:P), identified key climatic and edaphic controls through correlation analyses and linear mixed-effects models, and assessed differences in mediating stoichiometric responses to aridity among plant life forms along a strong aridity gradient in Xinjiang Uygur Autonomous Region, Northwest China. Leaf C, N, and P were quantified for 428 samples representing 315 species across 74 sites spanning an aridity-index (AI) range of 0.03-0.47 during June-August 2024. With increasing aridity, leaf N and P declined significantly, whereas leaf C remained relatively stable, leading to higher C:N and N:P ratios. At the driest sites (AI<0.10), mean leaf N and P concentrations were only 16.61 and 2.02 mg/g, respectively—about 46%-70% (for N) and 60%-75% (for P) lower than both the overall means and the values at mesic sites (AI>0.40). Soil organic carbon (SOC) showed significant positive correlations with leaf N and P. Herbs had higher N and P and lower C:N, C:P, and N:P than shrubs and trees. Mixed-effects models showed that species identity explained approximately 40% of the variance in leaf C, whereas environmental variables explained 13%-16% of variation in leaf N, P, and N:P. Aridity-driven nutrient limitation is governed by coupled climate-soil mechanisms and modulated by plant functional traits; leaf C:N:P stoichiometry is a robust indicator for monitoring and restoration in drylands under climate change. Our findings reveal that intensifying aridity shifts plants toward P-limitation, with important implications for predicting dryland vegetation responses to future warming and for designing effective ecological restoration strategies in arid regions.

Planting the drought-resistant vegetation is important to control desert in the world. However, the resistant mechanism to drought of psammophytes especially at the canopy scale remains unclear. To elucidate the mechanisms of water adaptation in Caragana korshinskii Kom. across various vertical canopy layers, we conducted an experiment in Dawukou District, Shizuishan City, Ningxia Hui Autonomous Region, China to measure hydraulic architecture and photosynthetic traits at different canopy heights under drought. Results showed a distinct vertical gradient in soil volumetric water content (VWC), characterized by water accumulation in deeper soil layers (60-80 cm) and depletion in shallower layers (0-20 cm). Under well-watered condition (70.00%-80.00% field capacity (FC)), the upper canopy achieved the highest photosynthetic rate (P_n) and transpiration rate (T_r); under moderate drought stress (40.00%-50.00% FC), photosynthetic amplitudes attenuated across all layers; under severe drought stress (10.00%-20.00% FC), the middle canopy became the primary photosynthetic refuge while lower-canopy photosynthesis nearly ceased. This hierarchical regulation strategy facilitated water conservation and survival under severe drought conditions. Upper-canopy photosynthetic and transpiration traits exhibited the strongest and most significant associations with shallow VWC (0-20 cm), reflecting rapid physiological adjustments to surface water fluctuations. By contrast, middle-canopy traits showed markedly weaker linkages to VWC, while lower-canopy traits displayed overall non-significant relationships with any measured soil layer, including 60-80 cm, indicating that lower leaves may depend on stored stem water or hydraulic redistribution rather than direct soil uptake. Furthermore, key ecological thresholds were identified as follows: (1) normal function: plant growth proceeded normally when VWC exceeded 3.04%, with optimal canopy WUE empirically confirmed within the measured VWC range of 10.07%-11.76%; (2) functional maintenance: as VWC declined to 1.52%-3.04%, photosynthetic activity gradually ceased in a layer-specific sequence—upper canopy<3.04%, lower canopy<2.03%, and middle canopy<1.52%; and (3) functional degradation: when VWC decreased to below 1.52%, total canopy photosynthesis ceased completely, indicating irreversible physiological decline. These findings provide an empirical basis for water management strategies, survival maintenance, and early-warning systems for degradation in C. korshinskii vegetation within arid areas.

Sucrose transporters (SUTs) play a pivotal role in carbon allocation, influencing plant growth, development, and stress responses. Eremosparton songoricum (Litv.) Vassilcz., a desert legume adapted to harsh environments, represents a valuable genetic resource for mining stress-tolerance genes. In this study, we identified 5 sucrose carrier (SUC) genes (EsSUC2, EsSUC3, EsSUC4a, EsSUC4b, and EsSUC8) in the E. songoricum genome, which phylogenetically clustered into the SUT1, SUT2, and SUT4 clades. These genes exhibited tissue-specific expression patterns and differential responses to various abiotic stresses. Notably, EsSUC8 (SUT1 clade) was predominantly up-regulated in response to salt stress, with subcellular localization confirming its targeting to the plasma membrane and validating its sucrose transport activity in the invertase-deficient yeast strain SUSY7/ura3. Heterologous overexpression of EsSUC8 in Arabidopsis thaliana (L.) Heynh. resulted in enhanced vegetative growth, earlier flowering, increased branching, and silique production, and ultimately an 8.65%-18.26% increase in seed yield. These yield improvements were associated with elevated sucrose accumulation in developing seeds. Furthermore, EsSUC8 overexpression enhanced salt tolerance, characterized by longer roots, reduced H₂O₂ accumulation, and higher root sucrose content under salt stress. Our results suggest that EsSUC8 is associated with changes in sucrose distribution under developmental and environmental stress.

Lycium barbarum L., valued for its potential immunomodulatory and metabolism-regulating functions, contains abundant bioactive compounds, including polysaccharides and betaine. The global demand for L. barbarum has grown rapidly at an annual rate exceeding 10.00%. Northwest China is the principal cultivation region. However, the highest urea application rate has induced soil acidification and nutrient imbalance, threatening the sustainability of this agricultural system. A three-year field experiment was conducted in the Wuwei oasis irrigation area to assess how different nitrogen (N) application rates affected fruit yield, fruit quality traits, and soil physicochemical properties. Four N rates, N0, N1, N2, and N3, supplied 0.00, 161.00, 322.00, and 483.00 kg N/hm², respectively, and a non-fertilized blank control (BLK) was included. Yield, betaine, polysaccharides, total flavonoids, soluble solids, soil pH, soil organic matter (SOM), total phosphorus (TP), available phosphorus (AP), and soil enzyme activities were determined. Compared with the BLK, N2 increased the fruit yield from 933.24 to 2899.71 kg/hm², an approximately threefold increase. Conversely, the highest N input decreased the soil pH and SOM in the 20-40 cm layer while increasing the surface soil electrical conductivity (EC). Under N3, the total flavonoid and betaine contents decreased by 14.78% and 55.32%, respectively. Thus, moderate N application improved fruit yield while maintaining fruit quality, whereas the highest N input reduced key functional components and enhanced the risk of soil degradation. These findings provide insights for optimizing N management in L. barbarum cultivation within arid regions.