Search Results (169)

Understanding alpine plants’ survival and reproduction is crucial for their conservation in climate change. Based on 423 valid distribution points, this study utilizes the MaxEnt model to predict the potential habitat and distribution dynamics of Leontopodium nanum under both current and future climate scenarios, while clarifying the key factors that influence its distribution. The primary ecological drivers of distribution are altitude (2886.08 m–5576.14 m) and the mean temperature of the driest quarter (−6.60–1.55 °C). Currently, the suitable habitat area is approximately 520.28 × 10⁴ km², covering about 3.5% of the global land area, concentrated mainly in the Tibetan Plateau, with smaller regions across East and South Asia. Under future climate scenarios, low-emission (SSP126), suitable areas are projected to expand during the 2050s and 2070s. High-emission (SSP585), suitable areas may decrease by 50%, with a 66.07% reduction in highly suitable areas by the 2070s. The greatest losses are expected in the south-eastern Tibetan Plateau. Regarding dynamic habitat changes, by the 2050s, newly suitable areas will account for 51.09% of the current habitat, while 68.26% of existing habitat will become unsuitable. By the 2070s, newly suitable areas will rise to 71.86% of the current total, but the loss of existing areas will exceed these gains, particularly under the high-emission scenario. The centroid of suitable habitats is expected to shift northward, with migration distances ranging from 23.94 km to 342.42 km. The most significant shift is anticipated under the SSP126 scenario by the 2070s. This study offers valuable insights into the distribution dynamics of L. nanum and other alpine species under the context of climate change. From a conservation perspective, it is recommended to prioritize the protection and restoration of vegetation in key habitat patches or potential migration corridors, restrict overgrazing and infrastructure development, and maintain genetic diversity and dispersal capacity through assisted migration and population genetic monitoring when necessary. These measures aim to provide a robust scientific foundation for the comprehensive conservation and sustainable management of the grassland ecosystem on the Qinghai–Tibet Plateau. Full article

Mineral imbalances in livestock can critically impair growth, immunity, and productivity. Yaks inhabiting the Qinghai–Tibetan Plateau face unique environmental challenges, including high-altitude-induced nutrient variability. This study investigated the status of mineral elements and their correlations with altitude in healthy yak calves across five regions in Ganzi Prefecture, located at elevations ranging from 3100 to 4100 m. Hair and serum samples from 35 calves were analyzed for 11 essential elements (Na, K, Ca, Mg, S, Cu, Fe, Mn, Zn, Co, and Se). The results revealed widespread deficiencies. Key deficiencies were identified: hair Na and Co were significantly below references value (p < 0.05), and Se was consistently deficient across all regions, with deficiency rates ranging from 35.73% to 56.57%. Serum Mg and Cu were generally deficient (Mg deficiency > 26% above 3800 m). S, Mn (low detection), and Co were also suboptimal. Serum selenium deficiency was notably severe in lower-altitude areas (≤59.07%). Significant correlations with altitude were observed: hair sodium levels decreased with increasing altitude (r = −0.72), while hair manganese (r = 0.88) and cobalt (r = 0.65) levels increased. Serum magnesium deficiency became more pronounced at higher elevations (r = 0.58), whereas selenium deficiency in serum was more severe at lower altitudes (r = −0.61). These findings indicate prevalent multi-element deficiencies in yak calves that are closely linked to altitude and are potentially influenced by soil mineral composition and feeding practices, as suggested by previous studies. The study underscores the urgent need for region-specific nutritional standards and altitude-adapted mineral supplementation strategies to support optimal yak health and development. Full article

The Qinghai–Tibetan Plateau (QTP), often referred to as the “Third Pole” of the world, harbors alpine grassland ecosystems that play an essential role as global carbon sinks, helping to mitigate the pace of climate change. Nonetheless, alterations in natural environmental conditions coupled with escalating human activities have disrupted the seasonal growth cycles of grasslands, thereby intensifying degradation processes. To date, the key drivers and lifecycle dynamics of Grassland Depletion across the QTP remain contentious, limiting our comprehension of its ecological repercussions and regulatory mechanisms. This study comprehensively investigates grassland degradation on the Qinghai–Tibetan Plateau, analyzing its drivers and changes in ecological suitability during the growing season. By integrating natural factors (e.g., precipitation and temperature) and anthropogenic influences (e.g., population density and grazing intensity), it examines observational data from over 160 monitoring stations collected between the 1980s and 2020. The findings reveal three distinct phases of grassland degradation: an acute degradation phase in 1990 (GDI, Grassland Degradation Index = 2.53), a partial recovery phase from 1996 to 2005 (GDI < 2.0) during which the proportion of degraded grassland decreased from 71.85% in 1990 to 51.22% in 2005, and a renewed intensification of degradation after 2006 (GDI > 2.0), with degraded grassland areas reaching 56.39% by 2020. Among the influencing variables, precipitation emerged as the most significant driver, interacting closely with anthropogenic factors such as grazing practices and population distribution. Specifically, the combined impacts of precipitation with population density, grazing pressure, and elevation were particularly notable, yielding interaction q-values of 0.796, 0.767, and 0.752, respectively. Our findings reveal that while grasslands exhibit superior carbon sink potential relative to forests, their productivity and ecological functionality are undergoing considerable declines due to the compounded effects of multiple interacting factors. Consequently, the spatial distribution of ecologically suitable zones has contracted significantly, with the remaining high-suitability regions concentrating in the “twin-star” zones of Baingoin and Zanda grasslands, areas recognized as focal points for future ecosystem preservation. Furthermore, the effects of climate change and intensifying anthropogenic activity have driven the reduction in highly suitable grassland areas, shrinking from 41,232 km² in 1990 to 24,485 km² by 2020, with projections indicating a further decrease to only 2844 km² by 2060. This study sheds light on the intricate mechanisms behind Grassland Depletion, providing essential guidance for conservation efforts and ecological restoration on the QTP. Moreover, it offers theoretical underpinnings to support China’s carbon neutrality and peak carbon emission goals. Full article

The blue-eared pheasant (Crossoptilon auritum), a Near Threatened (NT) species endemic to China, is primarily distributed across the northeastern region of the Qinghai–Tibetan Plateau. To bridge the fine-scale spatiotemporal gap in blue-eared pheasant behavioral ecology, this study combines satellite telemetry, movement modeling, and field-based habitat assessments (vegetation, topography, human disturbance). This multidisciplinary approach reveals detailed patterns of their behavior throughout the breeding season. Using satellite-tracking data from six individuals (five males tracked at 4 h intervals; one female tracked hourly) in Wanglang National Nature Reserve (WLNNR), Sichuan Province during breeding seasons 2018–2019, we quantified their home ranges via Kernel Density Estimation (KDE) and examined the female movement patterns using a Hidden Markov Model (HMM). The results indicated male core (50% KDE: 21.93 ± 16.54 ha) and total (95% KDE: 158.30 ± 109.30 ha) home ranges, with spatial overlap among individuals but no significant temporal variation in home range size. Habitat selection analysis indicated that the blue-eared pheasants favored shrub-dominated areas at higher elevations (steep southeast-facing slopes), regions distant from human disturbance, and with abundant animal trails. We found that their movement patterns differed between sexes: the males exhibited higher daytime activity yet slower movement speeds, while the female remained predominantly near nests, making brief excursions before returning promptly. These results enhance our understanding of the movement ecology of blue-eared pheasants by revealing fine-scale breeding-season behaviors and habitat preferences through satellite-tracking. Such detailed insights provide an essential foundation for developing targeted conservation strategies, particularly regarding effective habitat management and zoning of human activities within the species’ range. Full article

Simulating potential glacier collapses can provide crucial support for local disaster prevention and mitigation efforts. The Xiaomagou Glacier in the Amnye Machen Mountains, Qinghai–Tibetan Plateau, has experienced five collapses in the past two decades. Field investigation and remote sensing observations indicate that the topography and bedrock characteristics of the Qushi’an No. 22 Glacier, which is 3.5 km south of the Xiaomagou Glacier, are similar to those of the Xiaomagou Glacier. More importantly, the mass movement of the Qushi’an No. 22 Glacier since 2018 closely resembles that of the Xiaomagou Glacier exhibited before its previous collapses. Therefore, in the context of rising temperatures, it is possible that the Qushi’an No. 22 Glacier will collapse in the near future. Based on remote sensing imagery and the glacier’s surface elevation changes, we reconstructed the 2004 collapse process of the Xiaomagou Glacier via numerical simulation. The key parameters of the mass flow model were optimized based on the actual deposition area of the 2004 collapse. The model with optimized parameters was then used to simulate the potential Qushi’an No. 22 Glacier collapse. Two collapse scenarios were set for the Qushi’an No. 22 Glacier. In Scenario 1, the lower half of the tongue detaches; in Scenario 2, the whole tongue detaches. Simulation results show that, in Scenario 1, the maximum mass flow depth is 72 m, the maximum mass flow speed is 51.6 m/s, and the deposition area is 5.40 × 10⁶ km²; in Scenario 2, the maximum mass flow depth is 75 m, the maximum mass flow speed is 59.7 m/s, and the deposition area is 6.32 × 10⁶ km². In both scenarios, the deposition area is much larger than that of the Xiaomagou Glacier 2004 collapse, which had a deposition area of 2.21 × 10⁶ km². The simulation results suggest that the Qushi’an No. 22 Glacier collapse could devastate the pastures and township roads lying in front of the glacier, seriously affecting local transportation and livestock farming; furthermore, it may deposit in the Qinglong River, forming a large, dammed lake. At present, the Qushi’an No. 22 Glacier remains in an unstable state. It is crucial to strengthen monitoring of its surface morphology, flow speed, and elevation. Full article

Based on ascending and descending orbit SAR data from 2017–2025, this study analyzes the long time-series deformation monitoring and slip pattern of an active-layer detachment thaw slump, a typical active-layer detachment thaw slump in the permafrost zone of the Qinghai-Tibetan Plateau, by using the small baseline subset InSAR (SBAS-InSAR) technique. In addition, a three-dimensional displacement deformation field was constructed with the help of ascending and descending orbit data fusion technology to reveal the transportation characteristics of the thaw slump. The results show that the thaw slump shows an overall trend of “south to north” movement, and that the cumulative surface deformation is mainly characterized by subsidence, with deformation ranging from −199.5 mm to 55.9 mm. The deformation shows significant spatial heterogeneity, with its magnitudes generally decreasing from the headwall area (southern part) towards the depositional toe (northern part). In addition, the multifactorial driving mechanism of the thaw slump was further explored by combining geological investigation and geotechnical tests. The analysis reveals that the thaw slump’s evolution is primarily driven by temperature, with precipitation acting as a conditional co-factor, its influence being modulated by the slump’s developmental stage and local soil properties. The active layer thickness constitutes the basic geological condition of instability, and its spatial heterogeneity contributes to differential settlement patterns. Freeze–thaw cycles affect the shear strength of soils in the permafrost zone through multiple pathways, and thus trigger the occurrence of thaw slumps. Unlike single sudden landslides in non-permafrost zones, thaw slump is a continuous development process that occurs until the ice content is obviously reduced or disappears in the lower part. This study systematically elucidates the spatiotemporal deformation patterns and driving mechanisms of an active-layer detachment thaw slump by integrating multi-temporal InSAR remote sensing with geological and geotechnical data, offering valuable insights for understanding and monitoring thaw-induced hazards in permafrost regions. Full article

Gonghe Basin is an important frontier of resource and energy development and environmental protection on the Qinghai–Tibetan Plateau and upper sections of the Yellow River. As a characteristic ecotone, this area exhibits complex and diverse ecosystem types while demonstrating marked ecological vulnerability. The response of ecosystem services (ESs) to human activities (HAs) is directly related to the sustainable construction of an ecological civilization highland and the decision-making and implementation of high-quality development. However, this response relationship is unclear in the Gonghe Basin. Based on remote sensing data, land use, meteorological, soil, and digital elevation model data, the current research determined the human activity intensity (HAI) in the Gonghe Basin by reclassifying HAs and modifying the intensity coefficient. Employing the InVEST model and bivariate spatial autocorrelation methods, the spatiotemporal evolution characteristics of HAI and ESs and responses of ESs to HAs in Gonghe Basin from 2000 to 2020 were quantitatively analyzed. The results demonstrate that: From 2000 to 2020, the HAI in the Gonghe Basin mainly reflected low-intensity HA, although the spatial range of HAI continued to expand. Single plantation and town construction activities exhibited high-intensity areas that spread along the northwest-southeast axis; composite activities such as tourism services and energy development showed medium-intensity areas of local growth, while the environmental supervision activity maintained a low-intensity wide-area distribution pattern. Over the past two decades, the four key ESs of water yield, soil conservation, carbon sequestration, and habitat quality exhibited distinct yet interconnected characteristics. From 2000 to 2020, HAs were significantly negatively correlated with ESs in Gonghe Basin. The spatial aggregation of HAs and ESs was mainly low-high and high-low, while the aggregation of HAs and individual services differed. These findings offer valuable insights for balancing and coordinating socio-economic development with resource exploitation in Gonghe Basin. Full article

Strong UV-B radiation is one of the main climatic characteristics of the Qinghai–Tibet Plateau. Plants grown on the Tibetan Plateau are exposed to high-intensity UV radiation and therefore require effective mechanisms to adapt to these stresses. However, little attention has been paid to the response of grass–endophytic fungi symbiosis to UV-B radiation in this area. In this study, we investigated the relationship between Epichloë gansuensis and the growth and antioxidant responses of Achnatherum inebrians seedlings exposed to different UV-B doses, aiming to evaluate the growth and antioxidant capacity of A. inebrians seedlings under UV-B stress. The plant height, tillers, biomass, electrical conductivity, soluble sugars, malondialdehyde (MDA), proline, hydrogen peroxide (H₂O₂), superoxide dismutase (SOD), polyphenol oxidase (POD), and catalase (CAT) of A. inebrians seedlings were determined under different intensities of UV-B radiation treatments. The results showed that, with the increase in UV-B radiation intensity, the plant height, tiller and biomass of A. inebrians seedlings showed a decreasing trend, the electrical conductivity increased, malondialdehyde content increased, soluble sugar and proline content decreased, SOD, POD, and CAT activities showed a decreasing trend, and the content of H₂O₂ increased, which means that the UV-B radiation was able to inhibit the morphogenesis and aggravate the membrane lipid peroxidation of A. inebrians seedlings. The tolerance of the A. inebrians–E. gansuensis symbiont to UV-B may enable it to have a high infection rate on the Qinghai–Tibet Plateau. Full article

Plateau environments present unique mental health challenges owing to stressors including hypoxia, low temperatures, and intense ultraviolet (UV) radiation. These factors induce structural and functional alterations in the gut microbiota, disrupting gut-brain axis homeostasis and contributing to the higher prevalence of depression in plateau regions relative to flatland areas. For example, studies report that 28.6% of Tibetan adults and 29.2% of children/adolescents on the Qinghai-Tibet Plateau experience depression, with increasing evidence linking this trend to alterations in the gut microbiota. Dysbiosis contributes to depression through three interconnected mechanisms: (1) Neurotransmitter imbalance: Reduced bacterial diversity impairs serotonin synthesis, disrupting emotional regulation. (2) Immune dysregulation: Compromised gut barrier function allows bacterial metabolites to trigger systemic inflammation via toll-like receptor signaling pathways. (3) Metabolic dysfunction: Decreased short-chain fatty acid levels weaken neuroprotection and exacerbate hypothalamic-pituitary-adrenal axis stress responses. Current interventions—including dietary fiber, probiotics, and fecal microbiota transplantation—aim to restore microbiota balance and increase short-chain fatty acids, alleviating depressive symptoms. However, key knowledge gaps remain in understanding the underlying mechanisms and generating population-specific data. In conclusion, existing evidence indicates an association between plateau environments, the gut microbiota, and depression, but causal relationships and underlying mechanisms require further empirical investigation. Integrating multiomics technologies to systematically explore interactions among high-altitude environments, the microbiota and the brain will facilitate the development of precision therapies such as personalized nutrition and tailored probiotics to protect mental health in high-altitude populations. Full article

The temporal stability of alpine plant α-diversity remains poorly understood, constraining predictions of biodiversity dynamics. Here, this study examined spatiotemporal patterns in the temporal stability of plant α-diversity (species richness, Shannon, Simpson, and Pielou) across the Tibetan grasslands from 2000 to 2020. The temporal stability of plant α-diversity was more sensitive to changes in elevation compared to longitude and latitude. The greater the temporal stability of a plant species’ Shannon, the higher its rate of increase under the combined effects of climate change and human activities. The spatial average temporal stability of plant α-diversity declined by 8.83–16.40% across all the grasslands of the Qinghai-Xizang Plateau, while 39.34–43.77% of the region exhibited increasing trends under the combined effects of climate change and human activities. Climate change and human activities dominated 44.12–48.71% and 51.24–55.84% of grassland areas of the change of temporal stability of plant α-diversity, respectively. Radiation variability exerted some exclusive effects on the temporal stability of plant α-diversity. The relative change in plant α-diversity did not exhibit simple linear relationships with the relative change in its temporal stability. Therefore, climate change and human activities resulted in the spatial heterogenization of the temporal stability of plant α-diversity. While the overall temporal stability of plant α-diversity declined, some areas experienced local increases. Human activities drove changes in temporal stability across a broader area than climate change. In addition to climate warming and precipitation changes, attention should also be paid to the impact of radiation variability on the temporal stability of plant α-diversity. The relationships between plant α-diversity and its temporal stability were not always characterized by a trade-off or synergy. In future grassland biodiversity conservation efforts, it is essential to consider the potential influence of global dimming on the temporal stability of plant α-diversity. Simultaneously monitoring both α-diversity and its temporal stability, especially in areas where both are declining, should be a priority. Full article

As high-quality sheep germplasm resources in China, Hu sheep are characterized by fast growth and development, high fecundity, and tolerance to drought and cold. Tibetan sheep, adapted to high-altitude environments, have developed strong environmental adaptability. To explore the differences in the interaction among rumen microbial flora, hepatic gluconeogenesis, and mitochondrial function between Tibetan sheep and Hu sheep in the Qinghai–Tibet Plateau, this study systematically compared and analyzed the rumen flora density, key enzyme activities related to hepatic gluconeogenesis and mitochondrial function, and the expression levels of related genes in Tibetan sheep and Hu sheep under identical feeding management conditions, followed by correlation analysis. The results showed that Hu sheep had significantly higher densities of Ruminobacteramylophilus (Ram) and Fibrobacter succinogenes (Fs) associated with starch and protein degradation (p < 0.01). The expression levels of Forkhead box O1 (FOXO1), pyruvate carboxylase (PC) activity, and adenosine triphosphate (ATP) content were also significantly higher than those in Tibetan sheep (p < 0.01). In contrast, Tibetan sheep had higher densities of Butyrivibrio fibrisolvens (Bf), Ruminococcus albus (Ra), Ruminococcus flavefaciens (Rf), etc., related to cellulose degradation (p < 0.01). The gluconeogenesis-related genes, Glucose-6-phosphatase catalytic subunit 1 (G6PC1) and phosphoenolpyruvate carboxykinase1 (PCK1), and the activities of phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1,6-bisphosphatase (FBPase) were significantly higher in Tibetan sheep than in Hu sheep (p < 0.01). Mitochondrial function-related genes Mitofusin-1 (Mfn1), Mitofusin-2 (Mfn2), subunit 6 of ATP synthase (ATP6), cytochrome b (Cytb), etc., also showed significantly higher expression in Tibetan sheep (p < 0.01). While no significant differences were observed in the contents of citric acid (CA), pyruvic acid (PA), glucose (Glu), etc. (p > 0.05). Correlation analysis indicated that rumen flora was associated with the key enzyme activities and gene expressions of hepatic gluconeogenesis and mitochondrial function to varying degrees. In summary, Tibetan sheep exhibit strong fiber degradation capacity, the efficient utilization of gluconeogenic intermediates, and mitochondrial oxidative phosphorylation (OXPHOS) ability, forming adaptive strategies for high-altitude environments. By contrast, Hu sheep show efficient protein and starch degradation capacity, thereby enhancing the supply of gluconeogenic precursors. It is indicated that when introducing Hu sheep to high-altitude areas, dietary intervention can be used to regulate rumen microorganisms, such as increasing fiber-decomposing bacteria or enhancing mitochondrial oxidative capacity, to counteract metabolic limitations induced by hypoxia. Full article

Against the background of climate change, grazing accelerates the warming and drying processes in grasslands. There is a relatively clear temperature and humidity difference between grassland used for grazing and grassland that has been excluded from grazing practices. This paper asks whether temperature and humidity differences affect plant roots and cold resistance. Representative plants from an alpine meadow on the eastern margin of the Qinghai–Tibetan Plateau were selected under grazing exclusion and grazing conditions. Dominant plants within and outside of an alpine meadow enclosed for 10 years in the study area were selected as the research objects to study the root morphology and physiological indices of the cold resistance of these plants. The results showed that (1) grazing exclusion (GE) was beneficial for soil temperature and water retention, reduced soil pH, and increased soil nutrient content. Under grazing exclusion conditions, all plant root morphological traits, except root tissue density, increased compared with those under grazing grassland (FG) conditions. Grazed plants adopted resource acquisition strategies, while grazing exclusion plants adopted resource conservation strategies. (2) The changes in the physiological indices of cold resistance in different years and grazing treatments were different. In 2023, the superoxide dismutase (SOD) activity and soluble protein content in GE conditions were significantly lower than those in FG conditions, while the peroxidase (POD) activity was significantly higher than that under FG conditions. The activity of catalase (CAT) in the GE plot was significantly lower than that in the FG plot in 2024. The cold resistance of Gramineae species was lower than that of non-Gramineae plants. A redundancy analysis (RDA) of plant root morphological traits, soil properties, and cold resistance showed that root length and soil pH were the most important factors affecting plant cold resistance. We concluded that grazing exclusion is conducive to plant root growth, but also acidifies the soil and reduces plant cold resistance. Full article

We conducted experiments to screen annual forage oats suitable for cultivation at high altitude (4200 m), and to establish a green fertilization system with microbial fertilizers and manure organic fertilizers in order to provide technical support for a sustainable forage production system in the pastoral areas of the Qinghai–Tibetan Plateau. The experiment followed the principle of randomized block design to systematically analyze the agronomic traits, yield quality, and soil health of oats among different treatments, and to screen for adaptable oat varieties and the optimal application rate of microbial fertilizers with organic manure. The results showed that the following: (1) The results of the oat variety screening test showed that the yield and quality indexes of ‘Qing Yin No. 2’ and ‘Bai Yan No. 7’ introduced in high altitude areas were higher than those of other oat varieties, with high membership function values of 0.69 and 0.65, respectively. (2) The combined application of microbial fertilizer and organic fertilizer showed that the combined application could significantly improve the growth and photosynthetic characteristics of ‘Bai Yan No. 7’. The combination of the two also improved the yield quality of ‘Bai Yan No. 7’; the hay yield with the BHC3 treatment was 8508.00 kg·hm⁻², significantly higher than the BCK treatment (p < 0.05). Regarding soil fertility, under the BHC3 treatment, compared with the BCK, soil nutrient contents and soil enzyme activities were also significantly improved (p < 0.05). At the same time, the combination of the two treatments also significantly improved the growth and photosynthetic characteristics of ‘Qing Yin No. 2’. The combination of the two also improved the yield quality of ‘Qing Yin No. 2’, and the hay yield with the QDY4 treatment was 8707.67 kg·hm⁻², which was significantly increased by 25.37%, compared with that of QCK. Regarding soil fertility, under the QHC2 treatment, compared with the QCK treatment, soil nutrient contents and soil enzyme activities were also significantly improved. To sum up, ‘Qing Yin No. 2’ and ‘Bai Yan No. 7’ can better adapt to the ecological environment in high altitude areas, and are suitable for planting in areas with an altitude of 4200 m. The combined application of Trichoderma harzianum, Bacillus licheniformis, and organic fertilizer can improve the yield, nutritional quality, and soil fertility of ‘Qing Yin No. 2’ and ‘Bai Yan No. 7’. The best treatment for ‘Qing Yin No. 2’ is QDY4, that is, 15.00 kg of Bacillus licheniformis is applied per hectare, and 18,000 kg of cattle and sheep manure organic fertilizer is applied per hectare. The best treatment for ‘Bai Yan No. 7’ is BHC3, that is, 6.00 kg of Trichoderma harzianum is applied per hectare, and 18,000 kg of cattle and sheep manure organic fertilizer is applied per hectare. With the above treatment, the forage grass grows best, the soil nutrient content in the forage grass field is the highest, and the input–output ratio is the highest. Full article

Climate change and overgrazing significantly constrain the sustainability of meadow land and vegetation in the livestock industry on the Tibetan–Plateau ecosystem. In context of climate change mitigation, grassland soil C sequestration and forage sustainability, it is important to understand how manure regimes influence SOC stability, grassland soil, forage structure and nutritional quality. However, the responses of SOC fractions, soil and forage structure and quality to the influence of manure gradient practices remain unclear, particularly at Tianzhu belt, and require further investigation. A field study was undertaken to evaluate the soil bulk density, aggregate fractions and dynamics in SOC concentration, permanganate oxidizable SOC fractions, SOC stabilization and soil nutrients at the soil aggregate level under manure gradient practices. Moreover, the forage biodiversity, aboveground biomass and nutritional quality of alpine meadow plant communities were also explored. Four treatments, i.e., control (CK), sole sheep manure (SM), cow dung alone (CD) and a mixture of sheep manure and cow dung (SMCD) under five input rates, i.e., 0.54, 1.08, 1.62, 2.16 and 2.70 kg m⁻², were employed under randomized complete block design with four replications. Our analysis confirmed the maximum soil bulk density (BD) (0.80 ± 0.05 g cm⁻³) and micro-aggregate fraction (45.27 ± 0.77%) under CK, whilst the maximum macro-aggregate fraction (40.12 ± 0.54%) was documented under 2.70 kg m⁻² of SMCD. The SOC, very-labile C fraction (Cfrac₁), labile C fraction (Cfrac₂) and non-labile/recalcitrant C fraction (Cfrac₄) increased with manure input levels, being the highest in 2.16 kg m⁻² and 2.70 kg m⁻² applications of sole SM and the integration of 50% SM and 50% CD (SMCD), whereas the less-labile fraction (Cfrac₃) was highest under CK across aggregate fractions. However, manures under varying gradients improved SOC pools and stabilization for both macro- and micro-aggregates. A negative response of the carbon management index (CMI) in macro-aggregates was observed, whilst CMI in the micro-aggregate fraction depicted a positive response to manure addition with input rates, being the maximum under sole SM addition averaged across gradients. Higher SOC pools and CMI under the SM, CD and SMCD might be owing to the higher level of soil organic matter inputs under higher doses of manures. Moreover, the highest accumulation of soil nutrients,, for instance, TN, AN, TP, AP, TK, AK, DTPA extractable Zn, Cu, Fe and Mn, was recorded in SM, CD and SMCD under varying gradients over CK at both aggregate fractions. More nutrient accumulation was found in macro-aggregates over micro-aggregates, which might be credited to the physical protection of macro-aggregates. Overall, manure addition under varying input rates improved the plant community structure and enhanced meadow yield, plant community diversity and nutritional quality more than CK. Therefore, alpine meadows should be managed sustainably via the adoption of sole SM practice under a 2.16 kg m⁻² input rate for the ecological utilization of the meadow ecosystem. The results of this study deliver an innovative perspective in understanding the response of alpine meadows’ SOC pools, SOC stabilization and nutrients at the aggregate level, as well as vegetation structure, productivity and forage nutritional quality to manure input rate practices. Moreover, this research offers valuable information for ensuring climate change mitigation and the clean production of alpine meadows in the Qinghai–Tibetan Plateau area of China. Full article

The Yushu yak is one of China’s distinctive yak breeds, primarily distributed in the Yushu Tibetan Autonomous Prefecture of Qinghai Province and its surrounding areas. Yushu yaks are not only economically and culturally significant but also play a crucial role in protecting the ecosystem of the Qinghai-Tibet Plateau and promoting sustainable development. However, there are no clear records regarding the ancestry, population structure, and unique traits of Yushu yaks. Therefore, this study conducted an analysis of genetic diversity, population structure, and selection signals in Yushu yak populations, aiming to provide references for the conservation and utilization of the breed genetic resources. The results of the analysis showed that the Yushu yak population has high genetic diversity and low inbreeding coefficients, indicating a stable genetic structure. Population structure analysis revealed that the Yushu yak lineage is unique, with limited gene flow between domestic and wild yaks. Functional enrichment analysis of positively selected genes in Yushu yaks indicated prominent selection features related to growth and development as well as energy metabolism. Additionally, we classified the Yushu yak breeding bulls into family lineages based on kinship, which is essential for improving the efficiency of utilizing genetic resources and scientifically managing the population. Full article