Search Results (1,234)

The alpine grassland ecosystem of the Tibetan Plateau is a vital base for animal husbandry and a key ecological security barrier in China. Phosphorus (P), an essential nutrient, is among the primary factors limiting grassland productivity. However, the spatial distribution of soil P fractions across alpine grasslands on the Tibetan Plateau and their environmental drivers remain unclear, limiting our understanding of P cycling and grassland productivity. This study examined the composition and distribution of soil P in three representative alpine grasslands (meadow, steppe, and desert) using a combination of chemical fractionation and ³¹P nuclear magnetic resonance (NMR) spectroscopy. The results revealed pronounced spatial heterogeneity, with total soil P content varying by approximately 2.4-fold among the grassland types. Alpine meadows had the highest total P (0.73 g kg⁻¹) and available P (4.02 mg kg⁻¹) concentrations, with the latter being nearly twice that of alpine steppes and deserts. Alpine meadows were characterized by a predominance of labile and moderately labile organic P (e.g., NaOH-Po) and a diverse array of phosphate monoesters and diesters, whereas alpine deserts were dominated by stable, calcium-bound inorganic P (HCl-Pi). Temperature, precipitation, pH, and phosphatase activity were identified as key factors regulating the distribution and transformation of P fractions. The distinct P fractions and availability uncovered in this study are essential for predicting grassland ecosystem responses to environmental change and guiding sustainable pasture management on the Tibetan Plateau. Full article

Accurately assessing grazing impacts is essential for sustaining alpine grasslands. Conventional approaches often rely on total forage productivity, an indirect and uncertain proxy for forage availability. In this study, we propose a novel framework for estimating grazing pressure that integrates residual biomass with grazing intensity, thereby overcoming the limitations and uncertainties inherent in total forage-based assessments. Our results reveal pronounced spatiotemporal variation in grazing intensity: lowland areas experienced the highest intensity early in the growing season, whereas upland areas became more heavily grazed later in the season. However, grazing intensity alone proved insufficient to explain grazing pressure or predict pasture degradation risk. Overlay analyses demonstrated that only 38.8% of high intensity areas identified as under high grazing pressure, and more than 40% of high intensity area exhibiting substantial aboveground biomass. These findings highlight the limited explanatory power of grazing intensity when considered in isolation. By explicitly incorporating standing biomass rather than relying merely on total production, the proposed framework reduces estimation uncertainty, enhances ecological realism, and provides a scalable, more accurate and practical tool for monitoring grassland utilization and degradation. Full article

Ensuring equitable access to basic education is a core issue for promoting balanced regional development and sustainable educational outcomes. As a vast and sparsely populated region with relatively slow development, the Qinghai–Tibet Plateau faces particular challenges in ensuring educational accessibility and equity. Using a 100 m × 100 m travel time cost raster constructed from OSM road networks and the cost-distance method, together with local spatial autocorrelation, Lorenz curve, and Gini coefficients, as well as the Geodetector method, this study examines the spatial equity and factors influencing the accessibility of primary and secondary schools across 2798 townships at three time points (2016, 2020, and 2024) under three scenarios: Scenario 1 (nearby schooling), Scenario 2 (schooling within the prefecture-level city), and Scenario 3 (schooling within the county). The results show that: (1) Overall accessibility improved from 2016 to 2024, with primary schools being more accessible than secondary schools. Western townships, although initially disadvantaged, experienced the most notable gains. However, accessibility declined markedly when administrative-boundary constraints were imposed, with the greatest losses observed in ultra-high-altitude remote areas such as Ngari and Nagqu. (2) Spatial equity also improved, but when administrative boundaries were imposed, population-weighted inequities became even more pronounced than disparities in accessibility itself. Equity declined most sharply under county-level constraints, with pronounced impacts on both primary and secondary schooling. (3) Spatial variations in accessibility were jointly driven by multiple factors. In Scenario 1, road network density and population density had the strongest explanatory power. Under administrative boundary constraints, however, county type and ethnic autonomy became increasingly influential. In conclusion, in ultra-high-altitude areas where natural conditions remain difficult to overcome, improving educational equity depends less on transport expansion or facility provision and more on relaxing county-level boundary restrictions that constrain access to services. These findings may provide useful evidence to inform targeted policy interventions and resource allocation strategies aimed at promoting equitable access to basic education in underdeveloped and high-altitude regions. Full article

As viromics advances, the diversity and ecological significance of RNA viruses in global ecosystems are gaining growing recognition. Nevertheless, studies on RNA viruses in wildlife, especially non-model avian species, are still relatively scarce. This study employed viral metagenomics to systematically characterize the gut RNA viromes of three widely distributed corvid species on the Qinghai–Tibet Plateau: the Red-billed chough (Pyrrhocorax pyrrhocorax), Daurian jackdaw (Coloeus dauuricus), and Rook (Corvus frugilegus). These three corvid species are closely associated with human-inhabited areas on the Qinghai–Tibet Plateau and display distinctive scavenging behaviors that may lower their exposure to environmental pathogens while concurrently elevating their risk of viral infection, rendering them key targets for viral surveillance and research into zoonotic disease transmission. The analysis annotated viral communities into 4 phyla and 8 classes, with Pisuviricota and Kitrinoviricota emerging as the predominant phyla in all samples. Alpha diversity analysis indicated no significant differences among groups, while beta diversity showed significant compositional differences. KEGG annotation revealed that enriched functional pathways were mainly concentrated in “Global and overview maps”, “Drug resistance: antimicrobial”, and “Biosynthesis of other secondary metabolites”. Furthermore, 4 antibiotic resistance genes and 13 putative virulence factor genes were identified. Phylogenetic analysis further indicated that several identified viruses have the potential for cross-species transmission, underscoring the pivotal role of wild birds in viral ecosystems and disease spread. This study uncovered multi-faceted features of the gut RNA viromes in the three crow species, spanning structural, functional, and evolutionary dimensions. These results offer novel perspectives on the viromes of wild corvids and their potential contributions to viral emergence and dissemination in the Qinghai–Tibet Plateau ecosystem. Full article

To address the limitations of traditional groundwater quality assessment and prediction methods, this study integrates game theory and machine learning to investigate the drinking quality of groundwater in the southwestern Qinghai–Tibet Plateau. The results showed that the groundwater in the study area is generally weakly alkaline (mean pH: 8.08) and dominated by freshwater (mean TDS: 302.58 mg/L), with hardness levels mostly ranging from soft to medium. Major cations follow the concentration order: Ca²⁺ > Na⁺ > Mg²⁺ > K⁺; anions are in the sequence of HCO₃⁻ > SO₄²⁻ > Cl⁻. The hydrochemical type is mainly Ca-HCO₃. A few samples exceed the limit values specified in the Groundwater Quality Standard. Through multivariate statistical analysis, ion ratio analysis, and saturation index calculations, water-rock interaction is identified as the primary factor influencing groundwater chemistry. It consists of carbonate dissolution and silicate weathering, accompanied by cation exchange. The water quality index improved based on game theory, integrated subjective weights (from analytic hierarchy process) and objective weights (from entropy-weighted method), shows that the overall groundwater quality in the study area is good: 95.97% of the samples are high-quality water (WQI ≤ 50), more than 99% of the samples have a WQI < 150, which is suitable as drinking water sources; only 0.81% of the samples are of extremely poor quality, presumably related to local pollution. Linear regression achieved the best performance (R² = 0.99, RMSE≈0.00) with strong stability, followed by support vector machines (test R² = 0.98), while the extreme gradient boosting model showed overfitting. This study provides a scientific basis for groundwater management in river basins. Full article

Human settlements’ suitability in ecologically fragile regions is critical for sustainable development and ecological security. However, comprehensive assessments that integrate multiple natural environmental factors are insufficient. Here, we establish a human settlements suitability index (HSI) to assess human settlements’ suitability on the Qinghai–Tibet Plateau, including Relief Degree of Land Surface (RDLS), Temperature–Humidity Index (THI), Land Surface Water Abundance Index (LSWAI), and Land Cover Index (LCI). The results show that: (1) The RDLS of the Qinghai–Tibet Plateau was generally high, reflecting elevated terrain and steep topography, with strong regional variation. THI increases from the northwest arid region to the southeast, while high LSWAI and LCI were concentrated and show a zonal distribution. (2) The HSI ranged from 0.07 to 1, with seven suitability types. Low-suitability was distributed in the Kunlun, Gangdise, Himalayas, and the northern and southern parts of the Tibetan valleys. Mid-suitability appeared in the Sichuan–Tibet Alpine Canyon, while high-suitability was concentrated in the northeast (Qaidam Basin, Qilian, Hengduan Mountains), the west (Menyu), and the Qaidam Basin. (3) Low-suitability covered over 70% of the Qinghai–Tibet Plateau but hosts only 20% of the population. Mid-suitability occupied about 20% of the land, yet contained nearly 70% of the population. High-suitability (HSI > 0.7) areas were limited but concentrated populations in the Qaidam Basin, southern Tibetan valleys, and eastern Sichuan–Tibet Alpine Valleys. Future development should target these high-suitability regions to support sustainable population growth and reduce land pressure. These findings provide a scientific basis for regional planning, population distribution, and ecological security on the Qinghai–Tibet Plateau. Full article

The soil freeze–thaw process is a dominant disturbance in the seasonally frozen ground and the active layer of permafrost, which plays a crucial role in the surface energy balance, water cycle, and carbon exchange and has a pronounced influence on vegetation phenology. This study proposes a novel density-based Freeze–Thaw Disturbance Index (FTDI) based on the identification of the freeze–thaw disturbance region (FTDR) over the Qinghai–Tibet Plateau (QTP). FTDI is defined as an areal density metric based on geomorphic disturbances, i.e., the proportion of FTDRs within a given region, with higher values indicating greater areal densities of disturbance. As a measure of landform clustering, FTDI complements existing freeze–thaw process indicators and provides a means to assess the geomorphic impacts of climate-driven freeze–thaw changes during permafrost degradation. The main conclusions are as follows: the FTDR results that are identified by the random forest model are reliable and highly consistent with ground observations; the FTDRs cover 8.85% of the total area of the QTP, and mainly in the central and eastern regions, characterized by prolonged freezing durations and the average annual ground temperature (MAGT) is close to 0 °C, making the soil in these regions highly susceptible to warming-induced disturbances. Most of the plateau exhibits low or negligible FTDI values. As a geomorphic indicator, FTDI reflects the impact of potential freeze–thaw dynamic phase changes on the surface. Higher FTDI values indicate a greater likelihood of surface thawing processes triggered by rising temperatures, which impact surface processes. Regions with relatively high FTDI values often contain substantial amounts of organic carbon, and may experience delayed vegetation green-up despite general warming trends. This study introduces the FTDI derived from the FTDR as a novel index, offering fresh insights into the study of freeze–thaw processes in the context of climate change. Full article

Thermokarst lakes play a crucial role in regulating hydrological, ecological, and biogeochemical processes in permafrost regions. However, due to the limited spatial resolution of earlier satellite imagery, small thermokarst lakes—highly sensitive to climate change and permafrost degradation—have often been overlooked, hindering accurate spatiotemporal analyses. To address this limitation, five water indices—Modified Normalized Difference Water Index (MNDWI), Multi-Band Water Index (MBWI), Automated Water Extraction Index (AWEI_sh and AWEI_nsh), and Red Edge Water Index (RWI)—were employed based on Sentinel-2 imagery from 2021 to extract thermokarst lakes in the Qinghai–Tibet Highway (QTH) region, China. Visual validation indicated that the Red Edge Water Index (RWI) yielded the best performance, with an error of only 10.21%, significantly lower than other indices (e.g., MNDWI: 41.36%; MBWI: 38.80%). Seasonal comparisons revealed that the applicability of different water indices varies, with autumn months (September to October) being the optimal period for lake extraction due to stable and unfrozen surface conditions. Using the RWI, 56 thermokarst lake drainage events were identified in the study area from 2016 to 2025 (as of September 2025), most occurring after 2019—likely associated with climatic factors—and small lakes were found to be more prone to drainage, accompanied by notable surface subsidence in drained regions. These findings are applicable across the Qinghai–Tibet Plateau (QTP) and provide a scientific basis for monitoring thermokarst lakes, delineating accurate lake boundaries, and exploring drainage mechanisms. Full article

The severe degradation of alpine grasslands on the Qinghai–Tibet Plateau poses a significant threat to regional ecological security. While insects are critical for ecosystem functions, their responses to restoration measures in these fragile habitats are poorly documented. This study assessed the initial impacts of four restoration approaches—grazing exclusion fencing (FE), no-till reseeding (FR), planting grass (GC), and grazing control (CK)—on insect trophic guilds (herbivores, predators, saprophagous, and omnivores) in the Qilian Mountains. Using a multi-dimensional indicator (alpha, zeta, and dark diversity), we systematically assessed community assembly and recovery potential. The results revealed the following: (1) FE supported the highest insect abundance, dominated by phytophagous insects. FR significantly enhanced species’ richness and diversity across multiple functional groups (p < 0.05). GC significantly increased the richness of omnivorous insects, but caused a significant decrease in the Shannon–Wiener index for saprophagous insects (p < 0.05). (2) Zeta diversity revealed stable, widespread-species-dominated communities under FR and FE, while CK and GC favored rare-species-driven succession. Dark diversity analysis indicated high recovery potential for phytophagous insects under FR and FE, while GC enhanced saprophagous latent diversity. However, we emphasize that mechanistic interpretations require further validation. Our findings highlight no-till reseeding as a promising initial strategy, though longer-term studies are essential to evaluate successional trajectories and establish definitive management protocols for alpine grassland restoration. Full article

Tomato fruit malformation causes substantial yield and economic losses, but its molecular mechanisms are not well understood. This study compared floral traits of WT ‘QT57’ and malformed-fruit mutant ‘QT2’, integrated transcriptomic data, and qRT-PCR analysis to screen key candidate genes, and analyzed the pectinase gene family. The results found the ‘QT2’ mutant differed from WT ‘QT57’ in flower and fruit development. Expression analysis of CLAVATA-WUSCHEL pathway genes preliminarily validated the compensatory mechanism of SlCRCa and SlCRCb in ‘QT2’ malformed fruit. Six pectinase genes were identified as key candidates via RNA-seq and qRT-PCR analysis. Transcriptomic and qRT-PCR analyses of the pectinase gene family revealed their potential role in regulating tomato fruit malformation. Family analysis showed 34 pectinase genes distributed unevenly across 12 chromosomes. Subcellular localization confirmed SlPL7 in the nucleus and SlPME9 in the cell membrane/endoplasmic reticulum. The PL and PME genes were evolutionarily close, suggesting a potential functional overlap. Gibberellin-responsive elements were found in most pectinase genes. Pectinase genes may regulate tomato fruit malformation through the gibberellin-WUS pathway, carbohydrate metabolism, or cell wall metabolic disorder. This pathway provides new targets gene for the precise regulation of fruit malformation and offers significant reference value for practical production. Full article

Near space, as a critical atmospheric domain with unique physical, electromagnetic, and biological characteristics, remains a frontier with extensive unresolved scientific questions in atmospheric physics, electromagnetic environment dynamics, and biological adaptability mechanisms. In response to these knowledge gaps, the Chinese Academy of Sciences (CAS) initiated a strategic pilot science and technology project dedicated to systematically investigating the aforementioned three core domains of near space. This project has allowed for a series of near-space scientific experiments to be successfully conducted on the Qinghai–Tibet Plateau, utilizing large zero-pressure high-altitude balloons to carry diverse scientific payloads. From an engineering perspective, all experiments achieved complete success: high-altitude balloons with volumes ranging from 2000 m³ to 50,000 m³ safely transported scientific exploration equipment and payload cabins (with payload masses of 100 kg to 400 kg) to the near space; all scientific instruments maintained stable operational status throughout the missions; payload cabins reliably provided essential support functions, including power supply, data storage, real-time data transmission, and video monitoring for the scientific payloads; and both the scientific equipment and payload cabins were successfully recovered. These efforts are expected to enhance the scientific understanding of Earth’s near space environment and provide a technical foundation for subsequent large-scale near space exploration initiatives. Full article

Morphological plasticity (MP) is an essential strategy for plants in nutrient acquisition, disturbance alleviation, and community coexistence during environmental and climatic changes. However, to date, there has been little research concerning the MP for alpine–subalpine forests on the Qinghai–Tibet plateau. These forests are representative of the ectomycorrhizal (ECM) type, and morphological traits of these ECM roots, such as root tip lengths, diameters, and their adherent hyphal lengths and exploration types, have rarely been studied in the context of nutrient and environmental gradients. In this study, we examined the morphological traits of ECM roots for faxon fir (Abies fargesii var. faxoniana), which dominated in subalpine forests across nine elevations on the Eastern Qinghai–Tibet plateau. By quantifying ca. 90,000 root tips, the hyphal lengths of ectomycorrhizal extraradical mycelium (EEM, i.e., short- and long-distance exploration types) reached up to 1.1 × 10⁶ cm/m³ in soil, which decreased significantly due to gradually increasing altitude. In contrast, the variability of ECM root traits (diameter, length, and superficial area) was highly conserved along the altitudinal gradients, yet the root tip lengths were positively associated with soil protease enzyme activity. The increase in diameter and length of ECM root tips was climate-independent yet significantly associated with increasing root N concentration. In the studied forests, a long-distance exploration type of ECM hyphae was controlled by precipitation (p < 0.05), whereas the short-distance one was controlled by precipitation and temperature simultaneously. The EEM lengths of short- and long-distance exploration types were associated with high C concentration and low N concentration in host tree root tissues. Our findings demonstrated that MP expression in nutrient-foraging strategies for the dominant coniferous trees facilitates the adaptation to changing environments by specialized hyphal structures. In conclusion, ECM root tips and hyphal structures are two dimensions of functional traits linked to root N concentration in opposite ways, and their MP collectively ensures the temporal stability and resistance of subalpine forests on the Qinghai–Tibet plateau. These results provide new insights into ECM morphological traits and their adaptation in changing environments, which is valuable for understanding responses of subalpine forests to climate change. Full article

Przewalski’s gazelle (Procapra przewalskii) is an endangered ungulate endemic to the Qinghai–Tibet Plateau, with a small population size and exposure to multiple ecological pressures. Its gut microbiota may play a crucial role in host environmental adaptation. To investigate the functional divergence of gut microbial communities, we performed high-throughput metagenomic sequencing on 105 wild fecal samples collected from 10 geographic regions around Qinghai Lake. The results revealed significant regional differentiation in key functional modules related to metabolism, antibiotic resistance mechanisms, and virulence-associated pathways. All populations showed enrichment in core metabolic pathways such as carbohydrate and amino acid metabolism, with carbohydrate-active enzymes dominated by glycoside hydrolases (GHs) and glycosyltransferases (GTs), exhibiting overall functional conservation. Although populations shared many antibiotic- and virulence-related reference genetic markers, the marker composition associated with distinct resistance mechanisms and pathogenic processes exhibited clear population-specific patterns, suggesting differential microbial responses to local environmental pressures. Correlation network analysis further identified core taxa (e.g., Arthrobacter and Oscillospiraceae/Bacteroidales lineages) as key genera linking community structure with core metabolic, resistance-related, and virulence-associated marker functions. Overall, the gut microbiota of Przewalski’s gazelle exhibits a complex spatially structured functional differentiation, reflecting host–microbiome co-adaptation under region-specific ecological pressures. These findings provide critical methodological and theoretical support for microecological health assessment and regionally informed conservation management of this endangered species. Full article

The distinctive geographical environment of the Qinghai–Tibet Plateau has nurtured a variety of anthocyanin-rich berry plants. This review systematically summarizes the current state of research on anthocyanins obtained from Lycium ruthenicum Murr. (LRAs), Nitraria tangutorun Bobr (NTAs), and Rubus idaeus (RAs) for their potential health benefits and use. The anthocyanins found in these three berries have attracted considerable interest for their significant biological effects, such as their antioxidant, anti-aging, hypoglycemic, anti-inflammatory, and neuroprotective activities, as well as their ability to regulate the gut microbiota and inhibit cancer cells. These anthocyanins have potential applications as natural colorants, packaging materials and smart labels, as well as functional food and health supplements in the food industry. They have diverse molecular architectures with glycosylation and acylation profiles. The structural features of anthocyanins are closely related to their biological activities. This review provides a detailed overview of the chemical structures, synthesis pathways, biological activities, and applications in the food industry of LRAs, NTAs, and RAs. This summary offers a theoretical foundation for exploring plant resources characteristic of the Qinghai–Tibet Plateau and for the development and utilization of high-value-added functional foods, pharmaceuticals, and cosmetics. Full article