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Soil moisture， as a key hydrological variable connecting the surface and atmospheric water and heat exchange， affects the land-air water and heat exchange and carbon cycle process.However， due to the difficulty in monitoring soil moisture in alpine mountain areas， there are some difficulties in related research.The study of time stability can reduce the difficulty of soil moisture acquisition by selecting representative points.In this study， the slope of Shangzhangfanggou grassland in Shiyang River basin of Qilian Mountain was selected to set up a high-density and high-time resolution soil moisture monitoring network to explore the temporal and spatial variation and temporal stability of soil moisture on the slope scale in alpine mountainous areas.The research results show that： （1） The surface soil moisture （10 cm， 15.90%） is significantly higher than that in the deep layer （50 cm， 11.78%）， and its temporal variability （CvT=19.46%） is also stronger than that in the deep layer （CvT=10.67%）， but its spatial variability （CvS=20.05%） is weaker than that in the deep layer （CvS=27.06%）.（2） The time stability Index of Temporal Stability （0.24） is stronger than that of the deep layer （0.34）， and the surface layer and the deep layer can represent the surface soil moisture of the slope through 3 or 5 soil moisture monitoring points respectively （R2> 0.90）.（3） Slope position and soil hydrological properties have obvious influence on time stability， and the time stability point is more likely to appear at the position with larger bulk density and smaller shape parameter n under the slope.The research results are helpful to better understand the temporal and spatial variation law， temporal stability characteristics and control function of soil moisture on slope in alpine mountain areas.

Global warming in tandem with surface albedo reduction caused by black carbon (BC) deposition on glaciers accelerated glacier melting; however, their respective contributions remain unclear. Glaciers in the Qilian Mountains are crucial for the development of oases in the Hexi Corridor; however, their area has decreased by more than 20% over the past half-century. Thus, this study developed a dynamic deposition model for light-absorbing particles (LAPs), coupled with a surface energy and mass balance model. We comprehensively assessed the effects of BC and warming on the melting of a typical glacier in the Qilian Mountains based on the coupled model. BC on the glacier surface caused 13.1% of annual glacier-wide melting, of which directly deposited atmospheric BC reduced the surface albedo by 0.02 and accounted for 9.1% of glacier melting. The air temperature during 2000–2010 has increased by 1.5 °C relative to that during the 1950s, accounting for 51.9% of current glacier melting. Meanwhile, BC emission have increased by 4.6 times compared to those of the early Industrial Revolution recorded in an ice core, accounting conservatively for 6.3% of current glacier melting. Mitigating BC emissions has a limited influence on current glacier melting; however, in the long-term, mitigation should exert a noteworthy impact on glacier melting through the self-purification of glaciers.

Based on soil temperature and humidity and meteorological data at different elevations during the 2020-2021 growing season in the Pailugou watershed of Qilian Mountain， this study analyzed the variation characteristics of soil temperature and humidity and the relationship with meteorological factors， and determined the main meteorological factors affecting soil temperature and humidity.The results showed that： （1） soil temperature tended to increase and then decreased during the growing season （2020）， with a gradual increase in soil temperature from May to August （3.93 ℃） and a decrease from September to October （2.44 ℃）.Meanwhile， soil temperature showed a fluctuating increase with increasing elevation and a gradual decrease with increasing depth of soil layer.（2） Soil moisture showed considerable variation within the growing season， with a general trend of increase and then decrease （2020）， with the lowest soil moisture in May （0.164 m3·m-3） and the highest soil moisture in September （0.318 m3·m-3）.（3） The variation of soil moisture increases with elevation and decreases with the depth of the soil layer.（4） The main meteorological elements affecting soil temperature are air temperature and relative humidity， while soil moisture is mainly affected by air temperature and vapor pressure deficit.

Amidst global climate change and increased anthropogenic activities, the Qilian Mountains face critical ecological and environmental challenges, including vegetation degradation and declining carbon stocks. Therefore, effective mitigation strategies are critical to building China’s ecological security and enhancing carbon storage. This study constructed and optimized an ecological corridor in the Qilian Mountains using models, such as minimum spanning tree and carbon stock calculation. It combined geographic meta cellular automata and other methods to model ecological recovery in the Qilian Mountains following corridor construction and investigated the areas of particular concern. The results show that: (1) the distribution of the 118 extracted ecological source sites (2020) exhibited a pattern of “dense in the east and sparse in the west.” Compared with the results of the 2010 extraction, the source site area had shrunk by 0.87 % and number of sites had increased by 45.68 %. This implies that the shrinkage and fragmentation of source sites are still increasing, underscoring the urgent need for ecological corridors. (2) Compared to the pre-optimization period, the network node connectivity of the corridor network formed by the optimized 114 primary corridors and 131 secondary corridors has increased by 110 % and the network connectivity has increased by 112 %, which enhances the connectivity of the corridors. (3) From 2000 to 2020, the carbon stock in the Qilian Mountains decreased and then increased; with the construction of a corridor mountain range, the carbon stock can be further increased by 1.4748 million tons. Additionally, the Geographic Cellular Automata (GCA) model simulated that in 2030, the area of forest land in the Qilian Mountains, area of grassland, and carbon stock will increase by 71.75 km2, 313.87 km2, and 6.663 million tons, respectively. These results confirm that ecological protection and corridor construction promote ecological restoration and enhance carbon stocks in the Qilian Mountains, providing a scientific basis for future ecological projects and carbon stock analysis in the region.

Population density estimation is integral to the effective conservation and management of wildlife. The snow leopard Panthera uncia is categorized as Vulnerable on the IUCN Red List, and reliable information on its density is a prerequisite for its conservation and management. Little is known about the status of the snow leopard in the central and eastern Qilian Mountains, China. To address this, we estimated the population density of the snow leopard using a spatially explicit capture–recapture model based on camera trapping in Machang in the central and eastern Qilian Mountains during January–March 2019. We set up 40 camera traps and recorded 84 separate snow leopard captures over 3,024 trap-days. We identified 18 individual snow leopards and estimated their density to be 2.26/100 km2. Our study provides baseline information on the snow leopard and the first population estimate for the species in the central and eastern Qilian Mountains.

The Qilian Mountains, located on the northeastern edge of the Qinghai–Tibet Plateau, are characterized by unique high-altitude and cold-climate terrain, where permafrost and seasonally frozen ground are extensively distributed. In recent years, with global warming and increasing precipitation on the Qinghai–Tibet Plateau, permafrost degradation has become severe, further exacerbating the fragility of the ecological environment. Therefore, timely research on surface deformation and the freeze–thaw patterns of alpine permafrost in the Qilian Mountains is imperative. This study employs Sentinel-1A SAR data and the SBAS-InSAR technique to monitor surface deformation in the alpine permafrost regions of the Qilian Mountains from 2017 to 2023. A method for spatiotemporal interpolation of ascending and descending orbit results is proposed to calculate two-dimensional surface deformation fields further. Moreover, by constructing a dynamic periodic deformation model, the study more accurately summarizes the regular changes in permafrost freeze–thaw and the trends in seasonal deformation amplitudes. The results indicate that the surface deformation time series in both vertical and east–west directions obtained using this method show significant improvements in accuracy over the initial data, allowing for a more precise reflection of the dynamic processes of surface deformation in the study area. Subsidence is predominant in permafrost areas, while uplift mainly occurs in seasonally frozen ground areas near lakes and streams. The average vertical deformation rate is 1.56 mm/a, with seasonal amplitudes reaching 35 mm. Topographical (elevation; slope gradient; aspect) and climatic factors (temperature; soil moisture; precipitation) play key roles in deformation patterns. The deformation of permafrost follows five distinct phases: summer thawing; warm-season stability; frost heave; winter cooling; and spring thawing. This study enhances our understanding of permafrost deformation characteristics in high-latitude and high-altitude regions, providing a reference for preventing geological disasters in the Qinghai–Tibet Plateau area and offering theoretical guidance for regional ecological environmental protection and infrastructure safety.

The subalpine shrub zone of the Qilian Mountains is an important water-retaining area, and it is crucial to clarify the processes of its hydrological cycle. Therefore, based on the stable isotope values of different water bodies in the subalpine shrub zone of the eastern Qilian Mountains from May to October 2019, the characteristics of δD and δ18O of different water bodies and their hydraulic relationships with each other were studied. The results showed that the stable isotope values of precipitation exhibited the largest fluctuations, while they were the most stable for groundwater. Plant transpiration was stronger than the evaporation of other water bodies. The stable isotope of precipitation was enriched in high temperature and low humidity environments. Isotopic values of plant and soil water were higher and more stable on the semi-sunny slope than on the semi-shady slope. According to the stable isotopes, there was a strong hydraulic relationship between the different water bodies in the study area, and precipitation was the ultimate source of all of them. Precipitation replenished soil water through infiltration. Part of the soil water was absorbed by plants, while the rest continued to infiltrate to replenish groundwater. Groundwater and precipitation replenished the river water. HIGHLIGHTS The stable isotopes of precipitation, soil water, plant water, river water, and groundwater can vary because of season and slope orientation.; Isotopic values of plant and soil water were higher and more stable on the semi-sunny slope than on the semi-shady slope.; Water lines and isotopic analysis were used to qualitatively determine replenishment relationships among different water bodies.;

The study explores the impact of mine grassland restoration on plant communities and soil properties in alpine grasslands, a subject of significant interest due to the observed relationship between grassland changes, plant communities, and soil properties. While prior research has mainly focused on the consequences of grassland degradation on plant diversity and soil characteristics, the specific effects of varying restoration degrees in alpine mining grasslands at the regional scale remain poorly understood. To address this knowledge gap, we established 15 sampling plots (0.5m×0.5m) across five different restoration degrees within alpine mining grasslands in the Qilian Mountains, China. Our objective was to assess the variations in plant diversity and soil properties along these restoration gradients. We conducted comprehensive analyses, encompassing soil properties [soil water content (SWC), available nitrogen (AN), total phosphorus (TP), nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), total nitrogen (TN), available phosphorus (AP), soil organic carbon (SOC), nitrate nitrogen, soil pH, and electrical conductivity (EC)], plant characteristics (height, density, frequency, coverage, and aboveground biomass), and plant diversity indices (Simpson, Shannon-Wiener, Margalef, Dominance, and Evenness indexes). Our findings included the identification and collection of 18 plant species from 11 families and 16 genera across the five restoration degrees: Very Low Restoration Degree (VLRD), Low Restoration Degree (LRD), Moderate Restoration Degree (MRD), High Restoration Degree (HRD), and Natural Grassland (NGL). Notably, species like Carex duriuscula, Cyperus rotundus, and Polygonum viviparum showed signs of recovery. Principal component analysis and Pearson correlation analysis revealed that soil pH, SWC, SOC, NO3-N, and AN were the primary environmental factors influencing plant communities. Specifically, soil pH and EC decreased as restoration levels increased, while SWC, AN, TP, NH4-N, TN, AP, SOC, and NO3-N exhibited a gradual increase with greater restoration efforts. Furthermore, the HRD plant community demonstrated similarities to the NGL, indicating the most effective natural recovery. In conclusion, our study provides valuable insights into the responses of plant community characteristics, plant diversity, and soil properties across varying restoration degrees to environmental factors. It also elucidates the characteristics of plant communities along recovery gradients in alpine grasslands.

Surface albedo plays a pivotal role in the Earth’s energy balance and climate. This study conducted an analysis of the spatial distribution patterns and temporal evolution of albedo, normalized difference vegetation index (NDVI), normalized difference snow index snow cover (NSC), and land surface temperature (LST) within the Qilian Mountains (QLMs) from 2001 to 2022. This study evaluated the spatiotemporal correlations of albedo with NSC, NDVI, and LST at various temporal scales. Additionally, the study quantified the driving forces and relative contributions of topographic and natural factors to the albedo variation of the QLMs using geographic detectors. The findings revealed the following insights: (1) Approximately 22.8% of the QLMs exhibited significant changes in albedo. The annual average albedo and NSC exhibited a minor decline with rates of −0.00037 and −0.05083 (Sen’s slope), respectively. Conversely, LST displayed a marginal increase at a rate of 0.00564, while NDVI experienced a notable increase at a rate of 0.00178. (2) The seasonal fluctuations of NSC, LST, and vegetation collectively influenced the overall albedo changes in the Qilian Mountains. Notably, the highly similar trends and significant correlations between albedo and NSC, whether in intra-annual monthly variations, multi-year monthly anomalies, or regional multi-year mean trends, indicate that the changes in snow albedo reflected by NSC played a major role. Additionally, the area proportion and corresponding average elevation of PSI (permanent snow and ice regions) slightly increased, potentially suggesting a slow upward shift of the high mountain snowline in the QLMs. (3) NDVI, land cover type (LCT), and the Digital Elevation Model (DEM, which means elevation) played key roles in shaping the spatial pattern of albedo. Additionally, the spatial distribution of albedo was most significantly influenced by the interaction between slope and NDVI.

The Qilian Mountains constitute an important ecological security barrier in the northwest of China, with a wealth of habitat types and biological species. They have a profound impact on the surrounding area and even the world. However, due to both natural and anthropogenic influences, Achnatherum inebrians is widely distributed in this region, seriously threatening the balance of the grass-soil-livestock ecosystem. To explore appropriate restoration measures of alpine grassland of the Eastern Qilian Mountains degraded by the presence of A. inebrians, we studied the effects of restoration measures on the A. inebrians population, the grassland vegetation community, and soil characteristics following sward ripping (SR) and swarding ripping plus reseeding excellent forage (SREF) in Tianzhu County, Gansu Province; adjacent A. inebrians-type degraded alpine grassland without any measures was the control (CK). The SR and SREF inhibited A. inebrians growth and reproduction, increased the proportion of edible forage and the community species diversity, (especially aboveground biomass and sum of sub-coverage of edible forage by as much as two and three times), and improved soil nutrients and soil quality. The radar analysis showed that SREF had the best effect on the A. inebrians-type degraded alpine grassland. Correlation analysis showed that edible forage community, plant diversity, soil moisture, and available nutrient content were the main factors driving the restoration of this degraded alpine grassland. Implementing measures tailored to local conditions could effectively inhibit the spread of A. inebrians, stimulate edible forage growth, and improve the grassland plant community and soil environment. The results indicated a reasonable method of restoration for this poisonous weed-type degraded grassland and protection of the ecological environment.