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Exploring NDVI variation and what drives it on the Qinghai–Tibet Plateau can strategically inform environmental protection efforts in light of global climate change. For this analysis, we obtained MODIS NDVI data collected during the vegetative growing season, vegetation types for the region, and meteorological data for the same period from 2001 to 2020. We performed Theil–Sen trend analysis, Mann–Kendall significance testing, spatial autocorrelation analysis, and Hurst index calculation to review the spatiotemporal changes in NDVI characteristics on the plateau for various vegetation types. We used the correlation coefficients from these analyses to investigate how the NDVI responds to temperature and precipitation. We found the following: (1) Overall, the Qinghai–Tibet Plateau NDVI increased throughout the multi-year growing season, with a much larger area of improvement (65.68%) than of degradation (8.83%). (2) The four main vegetation types were all characterized by improvement, with meadows (72.13%) comprising the largest portion of the improved area and shrubs (18.17%) comprising the largest portion of the degraded area. (3) The spatial distribution of the NDVI had a strong positive correlation and clustering effect and was stable overall. The local clustering patterns were primarily low–low and high–high clustering. (4) The Hurst index had an average value of 0.46, indicating that the sustainability of vegetation is poor; that is, the trend of vegetation change in the growing season in a large part of the Qinghai–Tibet Plateau in the future is opposite to that in the past. (5) The plateau NDVI correlated positively with air temperature and precipitation. However, the correlations varied geographically: air temperature had a wide influence, whereas precipitation mainly influenced meadows and grassland in the northern arid zone. The overall temperature-driven effect was stronger than that of precipitation. This finding is consistent with the current research conclusion that global warming and humidification promote vegetation growth in high-altitude areas and further emphasizes the uniqueness of the Qinghai–Tibet Plateau as a climate-change-sensitive area. This study also offers a technical foundation for understanding how climate change impacts high-altitude ecosystems, as well as for formulating ecological protection strategies for the plateau. [ABSTRACT FROM AUTHOR]

A thorough understanding of the development process of grazing activities and an elucidation of their complex mechanisms are crucial for the formulation and adjustment of livestock management policies. In the Selinco region of the Qinghai–Tibet Plateau, we conducted a comprehensive analysis of year-end livestock numbers and densities over the past 30 years. The results indicate a gradual decline in overall livestock numbers in the Selinco region during this period, with a notable decrease between 2004 and 2014, followed by stabilization. Notably, the number of yaks has significantly increased, whereas the numbers of sheep, goats, and horses have markedly decreased. Regarding livestock density, there is a spatial pattern of decrease from northwest to southeast, with the density order being Seni District > Bange County > Anduo County > Shenzha County > Nima County > Shuanghu County. Between 2004 and 2014, most counties experienced a significant decline in livestock density, exhibiting a trough–peak pattern. However, after 2014, a complex spatiotemporal dynamic emerged. Concerning driving factors, from 1990 to 2004, rural population and economic development were the primary influences on livestock density. After 2004, forage–livestock balance management policies, snowstorms, and fluctuations in livestock prices likely became the main influencing factors. Further detailed analysis of these factors is essential for developing more effective management strategies. [ABSTRACT FROM AUTHOR]

Alluvial fans have been proven to have great utilisation potential in QTP, but to what extent they are suitable for agricultural development is unknown. Therefore, using the alluvial fan in the Lhasa River Basin (LRB) as a case study, this paper established an evaluation system of land suitability for agriculture (LSA). Principal component analysis (PCA) and the exhaustive method (EM) were used to define the minimum dataset (MDS) and then the LSA of the alluvial fan in the LRB was evaluated using a comprehensive index of LSA. Two scientific approaches were implemented to improve the LSA using a scenario simulation. The results showed that the MDS assessed by the EA was more representative compared to the PCA. Alluvial fans with suitable grades are mainly distributed in the Lhasa River's middle and lower reaches. Developing facility agriculture and repairing roads accessing the alluvial fans are effective approaches to improve the LSA, which can increase the suitable-grade area from 58.62% to 97.82% and 63.85%, respectively. Therefore, most alluvial fans in the LRB are suitable for developing agriculture, and under the influence of human activities, there will be more alluvial fans suitable for developing agriculture. Our research provides scientific methods for the sustainable development of land in alpine regions. [ABSTRACT FROM AUTHOR]

Copyright of Arid Land Geography is the property of Chinese Academy of Sciences, Xinjiang Institute of Ecology & Geography and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the agricultural areas of the Qinghai-Tibet Plateau, ultraviolet-B (UV-B) radiation varies widely. UV-B can affect the growth and development of plants. Turnip (Brassica rapa var. rapa) is an important traditional economic crop in the Qinghai-Tibet Plateau, but how turnip responds to UV-B and the complex molecular mechanisms underlying UV-B tolerance remains unclear. In this work, we found that landrace KTRG-B48b grew better and obtained a higher fresh weight of taproot in Lhasa and Kunming than landrace KTRG-B48a through common garden experiments. The phenotypic differences between the two landraces may be mechanism-based. Transcriptomes was used to analyze the differences between KTRG-B48a and KTRG-B48b. The relative expression levels of anthocyanin synthesis genes were upregulated significantly after UV-B treatment. In addition, KTRG-B48b produced less hydrogen peroxide and superoxide than KTRG-B48a. The high expression levels of anthocyanin-related genes can increase accumulation of anthocyanin, which can decrease reactive oxygen species accumulation and improved plant adaptation to the living environment of strong UV-B radiation on the Qinghai-Tibet Plateau. In this study, we proposed a model for turnip anthocyanin biosynthesis under strong UV-B radiation. Our results can provide an overview of the transcriptome response of turnip to UV-B tolerance, thus expanding our understanding the functions of anthocyanins biological in plants. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Saline lakes contributions to the carbon cycle is crucial to the Qinghai‐Tibetan Plateau (QTP) carbon budget. Here, based on the 8‐year direct measurement of CO2 flux over the Qinghai Lake (QHL) and 83 collected CO2 flux data estimated by pCO2 sampling from 45 lakes over the QTP, we identified the interannual variations of CO2 flux and its response to the extreme climate events. Results showed: (a) the QHL CO2 absorption weakened in the spring, autumn and winter and turn to CO2 emissions in the summer during 2013–2020; (b) with higher Ts and less precipitation, coupling of positive Pacific Decadal Oscillation (PDO) and El Niño enhanced the summer CO2 emissions; and (c) the PDO and ENSO had obvious superposition effect on the decrease of CO2 absorption in autumn. Our results show the potential mechanism of lake CO2 flux responses to extreme climate and further defines the significance of the QTP carbon budget and cycling. Plain Language Summary: The CO2 flux at the water‐air interface is especially important since it directly affects the accurate evaluation of the global carbon budget. However, lacking of long‐term continuous observation data left an undeniable gap on the interannual variations of CO2 flux and its respond to extreme climate events (the El Niño‐Southern Oscillation and Pacific Decadal Oscillation: ENSO and PDO) in saline lakes, although they are globally significant. Here, based on the 8‐year direct measurement of CO2 flux by eddy covariance system over the QHL and 83 collected CO2 flux data estimated by pCO2 sampling from 45 lakes over the QTP. This study found a weakening of CO2 absorption in the spring, autumn and winter, and an enhancing of CO2 emissions in the summer in QHL during 2013–2020, and first reported a notable transformation of carbon sink to source of saline lakes for responding to the extreme climate events. Moreover, the enhancing of CO2 emissions may be stronger in saline lakes than that in fresh lakes over QTP. The results firstly show the potential mechanism of lake CO2 flux responses to extreme climate and further defines the significance of the QTP carbon budget and cycling. Key Points: The QHL CO2 absorption weakened in spring, autumn and winter, and even turn to CO2 emissions in summer during 2013–2020In‐phase PDO and El Niño events enhanced the summer CO2 emissions in saline lake over QTPRising in Ts and decreasing in precipitation dominated the CO2 variations [ABSTRACT FROM AUTHOR]

Wetland ecosystems in the Qinghai-Tibet Plateau (QTP), the region with the richest biodiversity and the most important ecological barrier function at high altitudes, are highly sensitive to global change, and wetland plants, which are important indicators of wetland ecosystem structure and function, are also threatened by wetland degradation. Therefore, a comprehensive study of changes in the geographical distribution pattern of plant diversity, as well as species loss and turnover of wetlands in the QTP in the context of global climate change is of great importance for the conservation and restoration of wetland ecosystems in the QTP. In this study, species turnover and loss of 395 endemic wetland plants of the QTP were predicted based on the SSP2-4.5 climate change scenarios. The results showed that there were interspecific differences in the effects of climate change on the potential distribution of species, and that most endemic wetland plants would experience range contraction. Under the climate change scenarios, the loss of suitable wetland plant habitat is expected to occur mainly in parts of the southern, north-central and north-western parts of the plateau, while the gain is mainly concentrated in parts of the western Sichuan Plateau, the Qilian Mountains, the Three Rivers Source Region and the northern Tibetan Plateau. Overlaying the analysis of priority protected areas with the established protected areas in the QTP has resulted in the following conservation gaps: the eastern Himalayan region, midstream of the Yarlung Zangbo River, the transition zone between the northern Tibetan Plateau and the Hengduan Mountains, Minshan-Qionglai mountain, Anyemaqen Mountains (southeast) to Bayankala (southeast) mountains, the southern foothills of the Qilian Mountains and the northern Tibetan Plateau region. In the future, the study of wetland plant diversity in the QTP and the optimisation of protected areas should focus on the conservation gaps. This study is of great importance for the study and conservation of wetland plant diversity in the QTP, and also provides a scientific basis for predicting the response of wetland plants to climate change in the QTP. [ABSTRACT FROM AUTHOR]

Roads are an increasingly prevalent form of human activity that drives the decrease in plant community functions and threatens global biodiversity. However, few studies have focused on the changes in the function and diversity of alpine meadows caused by road infrastructure in the Tibetan Plateau. In this study, the changes in species diversity, functional diversity, and community stability were examined at different distances from the Qinghai-Tibet highway. The results showed that the road intensified the degradation of vegetation, which significantly altered species diversity and community structure. This effect gradually decreased from near to far from the highway. Plant community cover and species diversity were highest at intermediate distances (50-100 m) from the roadway; species diversity and stability were lowest in the grassland most disturbed by the road (0 m), and species diversity and functional diversity tended to stabilize farther away from the road (250 m). Our findings indicate that changes in species diversity are synchronized with changes in functional diversity, which largely determines the outcome of degraded grassland community diversity and stability. Our results provide a reference point for restoring degraded alpine areas and mitigating the ecological impacts of roads. [ABSTRACT FROM AUTHOR]

Climate change is causing permafrost in the Qinghai–Tibet Plateau to degrade, triggering thermokarst hazards and impacting the environment. Despite their ecological importance, the distribution and risks of thermokarst lakes are not well understood due to complex influencing factors. In this study, we introduced a new interpretable ensemble learning method designed to improve the global and local interpretation of susceptibility assessments for thermokarst lakes. Our primary aim was to offer scientific support for precisely evaluating areas prone to thermokarst lake formation. In the thermokarst lake susceptibility assessment, we identified ten conditioning factors related to the formation and distribution of thermokarst lakes. In this highly accurate stacking model, the primary learning units were the random forest (RF), extremely randomized trees (EXTs), extreme gradient boosting (XGBoost), and categorical boosting (CatBoost) algorithms. Meanwhile, gradient boosted decision trees (GBDTs) were employed as the secondary learning unit. Based on the stacking model, we assessed thermokarst lake susceptibility and validated accuracy through six evaluation indices. We examined the interpretability of the stacking model using three interpretation methods: accumulated local effects (ALE), local interpretable model-agnostic explanations (LIME), and Shapley additive explanations (SHAP). The results showed that the ensemble learning stacking model demonstrated superior performance and the highest prediction accuracy. Approximately 91.20% of the total thermokarst hazard points fell within the high and very high susceptible areas, encompassing 20.08% of the permafrost expanse in the QTP. The conclusive findings revealed that slope, elevation, the topographic wetness index (TWI), and precipitation were the primary factors influencing the assessment of thermokarst lake susceptibility. This comprehensive analysis extends to the broader impacts of thermokarst hazards, with the identified high and very high susceptibility zones affecting significant stretches of railway and highway infrastructure, substantial soil organic carbon reserves, and vast alpine grasslands. This interpretable ensemble learning model, which exhibits high accuracy, offers substantial practical significance for project route selection, construction, and operation in the QTP. [ABSTRACT FROM AUTHOR]

Alpine grassland ecosystems are the most important ecosystem type, exhibiting a high sensitivity to anthropogenic nitrogen (N) and phosphorus (P) inputs into terrestrial ecosystems and significantly affecting the carbon (C) cycle within these ecosystems. However, the effects of N and P additions on soil C stability and the processes of organic C transformation remain unclear. This study measured the soil enzyme activities and oxidizable C fractions over a 9-year period following N and P additions to an alpine meadow in the Qinghai–Tibet Plateau. It included four treatments: control (CK), N addition, P addition, and combined N and P addition (NP), utilizing statistical methods such as analysis of variance (ANOVA), correlation analysis, and redundancy analysis. The findings indicated that NP addition significantly increased the non-labile soil oxidizable C fraction in the topsoil layer. Redundancy and correlation analyses revealed strong associations between the vegetation characteristics, C-cycling enzyme activities, soil-oxidized C fractions, and SOC stability index. These results underscore the role of NP addition in enhancing SOC accumulation and stability in grassland ecosystems, with the soil vegetation properties and C source enzyme activities serving as key regulators of the SOC stability. This study offers valuable insights into predicting the SOC dynamics amid rising N and P availability, thereby elucidating the effect of nutrient addition on soil C-cycling mechanisms. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet Plateau is an important ecological security barrier in China. Considering the rich local waste biomass with a single treatment method and low level of resource utilization, biochar utilization of solid waste biomass can be carried out based on the research that biochar has abundant material sources. According to the application methods of various types of solid waste resources that have not been carried out, this review analyzes and discusses various types of waste biomass resources in the plateau region, such as sewage plant sludge, food waste, green leaves, barley straw, yak manure, and the unique Tibetan tea and Tibetan medicine residue waste, and reviews the biochar methods and applications for similar raw materials at home and abroad. Further, the technical outlook of solar pyrolysis technology and UV radiation modification technology and the development of hybrid pyrolysis to enhance the performance of biochar materials and heavy metal passivation are proposed by utilizing the solar energy resources of the Tibetan Plateau. Collectively, it provides a reference for prevention and restoration methods for the fragile ecological environment of the Qinghai-Tibet Plateau, reduces the pressure of waste disposal in the region, and realizes the resource utilization of waste. [ABSTRACT FROM AUTHOR]

Over the past two decades, due to the combined effects of natural and human factors, the ecological environment and resources of the Qinghai–Tibet Plateau (QTP) have faced serious threats, profoundly impacting its ecosystem and the lives of its residents. Therefore, the establishment of the ecological security pattern (ESP) is crucial to cope with climate change, maintain ecosystem function, and sustainable development. Based on the Pressure–State–Response (PSR) model, this study constructed an evaluation index system for the ecological security (ES) of the QTP, evaluated the ES of the QTP during 2000–2020, and predicted the ES of the QTP during 2025–2035 based on the deep learning model. Combined with the residents' perception of ES, the ES of the QTP was evaluated comprehensively. The results showed that: (1) From 2000 to 2020, the ES value of the QTP continued to rise, the number of dangerous and sensitive counties decreased, and the number of other counties increased. The overall spatial distribution features higher values in the southeast and lower values in the northwest and central regions. (2) From 2000 to 2020, both hot spots and cold spots on the QTP decreased, with the hot spots mainly concentrated in the southeast of the QTP, represented by Yunnan Province, and the cold spots shifting from west to east, mainly concentrated in the central QTP, represented by Qinghai Province. (3) The Long Short-Term Memory (LSTM) model demonstrates high prediction accuracy. Based on the prediction of LSTM, the ES value of the QTP will continue to rise from 2025 to 2035, and the number of safe counties will reach the highest level in history. The spatial distribution is still higher in the southeast and lower in the northwest and central regions. (4) By analyzing residents' perception of 25 potential factors that may affect the ES of the QTP, the results show that residents generally believe that these factors have an important impact on ES, and their evaluation is between "important" and "very important". In addition, there is a significant correlation between these factors and the predicted values of ES. The results of the study will help to improve our understanding of the overall ecological environment of the QTP, provide accurate positioning and reasonable help for the government to formulate relevant protection strategies, and lay a methodological and practical foundation for the sustainable development of the QTP. [ABSTRACT FROM AUTHOR]

Permafrost ground ice melting could alter hydrological processes in cold regions by releasing water. Currently, there is a lack of gridded data of ground ice from the Qinghai‐Tibet Plateau (QTP). Using 664 borehole sample records, we applied a random forest (RF) method to predict the ground ice content of permafrost between 2 and 10 m depth in three layers (2–3, 3–5, and 5–10 m) at a spatial resolution of 1 km. The RF predictions demonstrated an R2 value exceeding 0.80 for all three layers with a negligible positive overestimation (0.98%–1.85%). The ground ice content of the first layer (2–3 m) can be predicted primarily using climate variables, but the contribution of terrain and soil variables increases as the depth increases. The total water storage of ground ice across the QTP permafrost (2–10 m depth) is approximately 3330.0 km3, with 403.5 km3 in the 2–3 m layer, 857.2 km3 in the 3–5 m layer, and 2069.3 km3 in the 5–10 m layer. This study generated for the first time a gridded dataset of the shallow permafrost ground ice content across the entire QTP which can be used to improve simulations of hydrological processes in the permafrost regions. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The poverty-stricken counties on the Qinghai-Tibet Plateau are characterized by ecological vulnerability and ecological degradation, which are vulnerable to economic development and human activities, thereby leading to frequent alterations of Land carbon sink changes. Therefore, it is of great significance to study the changes of land carbon sink capacity during the process of eradication of extreme poverty in poverty-stricken counties. Using remote sensing images and socio-economic data, this paper constructed land transfer matrix and land carbon sink model to analyze the changes of land carbon sink capacity in poverty-stricken counties and identified the relevant impact factors through geographic detectors. The results show significant changes in carbon sink-type land and a continuous decrease in the snow area, resulting in an obvious trend of grassland area decrease and barren area increase. Land carbon sink capacity of poverty-stricken counties during the eradication of extreme poverty is higher with an added value of 2.74 times than that before this period. Using the geographic detector to analyze the related factors, strong explanatory power was found in cash crops per capita, share of secondary industry, population density and per capita savings on the changes of carbon sink capacity in poverty-stricken counties. [ABSTRACT FROM AUTHOR]

Alpine wet meadows are known as N2O sinks due to nitrogen (N) limitation. However, phosphate addition and N deposition can modulate this limitation, and little is known about their combinative effects on N2O emission from the Qinghai-Tibet Plateau in wet meadows. This study used natural wet meadow as the control treatment (CK) and conducted experiments with N (CON2H4 addition, N15), P (NaH2PO4 addition, P15), and their combinations (CON2H4 and NaH2PO4 addition, N15P15) to investigate how N and P supplementation affected soil N2O emissions in wet meadow of QTP. Contrary to previous studies on grasslands, the effect of phosphate addition treatment on soil N2O flux was not detectable during the growing seasons of 2019 and 2020. Over a span of two years, the N addition treatment significantly increased the N2O flux by 3.45 μg⋅m–2⋅h–1 due to increased soil N availability. Noticeably, phosphate addition intensified the effect of N deposition treatment on soil N2O flux with high significance in the early growth season of 2020. This augmentation can be attributed to the alleviation of limiting factors imposed by plants and microorganisms on soil N and P, fostering the mineralization and decomposition of litter and soil nutrients by microorganisms. Consequently, the results showed that total nitrogen and nitrate nitrogen were the main controls on soil N2O emission under N and P addition. In addition, redundancy analysis showed that the relative abundance of NirK genes in soil microorganisms (Bradyrhizobium, Devosia, Ochrobactrum, Alcaligenes, Rhizobium) is the main factor affecting N2O flux and available nitrogen. We project that if nutrient input continues to increase, the main limiting factor of soil will change from N restriction to P restriction due to the unique microbial nitrogen conversion process in the alpine meadow, significantly increasing N2O emissions. Consequently, the heightened contribution of alpine wet meadows to global warming and ozone depletion hinges on the dynamics of nutrient input regimes, spotlighting the urgent need for informed environmental management strategies.

The Qinghai-Tibet Plateau (QTP) has undergone substantial warming, resulting in extensive permafrost degradation and a pronounced increase in landslide frequency. However, the causal link between climate warming and permafrost landslide occurrences remains poorly understood. A comprehensive inventory of permafrost landslides along the Qinghai-Tibet Engineering Corridor (QTEC) from 2016 to 2022 was compiled through remote sensing and field verification, along with an analysis of landslide triggering factors based on data from 5 weather stations, 4 active layer thickness observation sites, and 3 precipitation stations. From 2000 to 2020, the mean annual air temperature (MAAT) showed an increase of 0.5°C per decade, while precipitation remained relatively stable. A notable peak occurred in 2016, with MAAT and mean annual surface ground temperature rising sharply by 0.59°C and 0.41°C, respectively, from the previous year. In the same year, active layer thickness across observation sites increased by an average of 18.5 cm, exceeding the average thickening rate. This substantial deepening of the active layer suggests that a portion of the underlying permafrost, potentially ice-rich near the permafrost table, thawed during the warm season. Laboratory experiments further reveal a three-stage reduction in soil strength as temperatures approach 0°C, with the most pronounced decline at −1°C. Interpretation of landslide data shows that landslide frequency in 2016 significantly increased, reaching approximately 1.3 times the historical total. This suggests that a thawed interlayer forming at the active layer-permafrost interface plays a dominant role in landslide initiation. The thawed layer acts as a weak zone, enabling the downward movement of the overlying active layer and contributing to slope instability. These findings provide robust evidence linking temperature rise to permafrost-related landslides, offering new insights into the mechanisms of temperature-induced slope instability in high-altitude regions.

Study region: Qinghai-Tibet Plateau (QTP). Study focus: The Qinghai-Tibet Plateau (QTP) is sensitive to climate change and ecologically fragile. Researches on precipitation over the QTP mainly focus on quantity and frequency, overlooking its temporal distribution. However, subtle changes in precipitation can significantly impact the natural environment and lead to natural disasters. This work primarily focuses on the response of meteorological drought and vegetation growth to the precipitation temporal structure. The precipitation temporal structure is quantified from the perspectives of the contribution of heavy precipitation (concentration index, CI) and the temporal distribution of total precipitation (standardized variability index, SVI) using CPC unified gauge-based analysis of global daily precipitation over 1982–2022. New hydrological insights for the regions: The CI and SVI exhibit a significant decreasing trend across almost the entire QTP, which means the temporal distribution of precipitation has become more ''even'' within a year. Meteorological drought was analyzed using the sc-PDSI and SPEI-12 indices. Both indices indicate that drought has intensified in both the humid regions (southeastern QTP) and arid regions (northern QTP). However, in the transition zone between dry and humid areas, drought conditions have shown signs of alleviation. Analysis of the vegetation indicates a greening trend across the QTP, particularly in the northeastern regions. CI is more superior than the SVI in characterizing vegetation growth, especially in the transitional zones between bare land and grassland where precipitation is sparse. The findings provide a scientific basis for vegetation restoration and drought risk management on the QTP.

ABSTRACTDigital Elevation Models (DEMs) are critical datasets in the field of Earth sciences, essential for accurate measurement and analysis of the Earth's surface. We used ICESat-2 to quantitatively evaluate 5 DEMs (ALOS PALSAR, ASTER GDEM V3, COPERNICUS, NASADEM and TanDEM-X) on the Tibetan Plateau. The research findings indicate that the ALOS exhibits the highest level of accuracy, as evidenced by its root mean square error (RMSE) value of 5.05m. It is closely followed by NASA and COP, which have RMSE values of 6.23m and 8.10m, respectively. In contrast, the ASTER and TDX90 demonstrate comparatively lower levels of accuracy, as indicated by their respective RMSE values of 11.47m and 12.32m. It is worth mentioning that the accuracy of DEMs is significantly influenced by land cover, especially during the transition from areas with low vegetation to those with high vegetation. This transition often results in a decrease in accuracy. Furthermore, the accuracy of DEMs tends to decrease with increasing slope values. Aspect exhibits a notable spatial distribution pattern characterized by a "low in the Southwest direction, high in all other directions" phenomenon. This study offers significant contributions to the evaluation of DEMs accuracy and its suitability in the Qinghai-Tibet Plateau.

Soil moisture plays a crucial role in understanding the hydrological cycle and the ecological environment. This research presents an improved change detection method that leverages time series data from Sentinel-1 radar and Sentinel-2 optical sensors (2019–2021) to estimate surface soil moisture. The response of backscatter to soil moisture in bare soil was expressed in a logarithmic form, and the influence function of the normalized difference vegetation index (NDVI) on the backscatter difference was established for various vegetation-covered surfaces. Therefore, the impact of vegetation on backscatter is effectively mitigated, and the resulting change in backscatter relative to bare soil conditions can be obtained. An empirical function is subsequently formulated to ascertain the reference values of soil moisture in each pixel. The retrieval of soil moisture is demonstrated in the Wudaoliang permafrost region of the Qinghai-Tibet Plateau and validated against ground measurements. The retrieval results of the improved change detection method exhibit correlation coefficients ranging from 0.672 to 0.941, with root mean squared errors (RMSE) ranging from 0.031 [Formula: see text] to 0.073 [Formula: see text]. Compared to the Soil Moisture Active Passive (SMAP) 9-km product, our new method demonstrates higher correlation (0.898 vs. 0.867) and lower RMSE (0.037 [Formula: see text] vs. 0.044[Formula: see text]). The soil moisture retrieved from Sentinel shows a strong correlation with the SMAP 9-km soil moisture in the time series, thereby providing a better representation of the region’s soil moisture heterogeneity. Our method demonstrates the feasibility of combining Sentinel-1 and 2 for high-resolution (100 m) soil moisture mapping in permafrost regions.

ABSTRACTThe extreme environmental conditions of a plateau seriously threaten human health. The relationship between gut microbiota and human health at high altitudes has been extensively investigated. However, no universal gut microbiota biomarkers have been identified in the plateau population, limiting research into gut microbiota and high-altitude adaptation. 668 16s rRNA samples were analyzed using meta-analysis to reduce batch effects and uncover microbiota biomarkers in the plateau population. Furthermore, the robustness of these biomarkers was validated. Mendelian randomization (MR) results indicated that Tibetan gut microbiota may mediate a reduced erythropoietic response. Functional analysis and qPCR revealed that butyrate may be a functional metabolite in high-altitude adaptation. A high-altitude rat model showed that butyrate reduced intestinal damage caused by high altitudes. According to cell experiments, butyrate may downregulate hypoxia-inducible factor-1α (HIF-1α) expression and blunt cellular responses to hypoxic stress. Our research found universally applicable biomarkers and investigated their potential roles in promoting human health at high altitudes.

Debris flows have occurred in two adjacent gullies, namely Sedongpu Gully (SDP) and Zelongnong Gully (ZLN), since the 1950s. The most recent event occurred in ZLN in 2020, causing damage to human communities and infrastructure. Despite their close geographical proximity to the Great Bend of the Yarlung Zangbo River, SDP has experienced more frequent and severe events compared to ZLN. This paper aims to compare the evolutionary characteristics of mass movement between these two gullies. A comprehensive review of 12 debris flow events in both gullies from 1950 to 2020 was conducted. A novel method was proposed and verified for quantifying the debris flow mass movement by integrating InSAR, multi-DSMs, optical images, and field investigations. Comparative analysis revealed distinct evolutionary stages between the gullies, with SDP exhibiting mixed hillslope and channelized debris flows, whereas ZLN primarily experienced channelized debris flows. SDP witnessed a decrease in rainfall and temperature triggering debris flows, contrasting with ZLN where both factors increased. These explained the smaller frequency and magnitude of debris flows in ZLN. Overall, this study emphasizes the need for tailored risk prevention and control measures that reflect the specific dynamics of each gully.

Monitoring ongoing permafrost degradation on the Qinghai–Tibet Plateau is challenging because of its underground characteristics. Interferometric synthetic aperture radar (InSAR) technology, which can detect large-scale and high-precision surface deformation, has become an effective tool for indirect permafrost monitoring. Traditional InSAR methods usually solve permafrost deformation independently and on a point-by-point basis with high coherence, while existing permafrost deformation models ignore the interannual variation in deformation. This paper proposes an improved multi-temporal InSAR (MT-InSAR) method based on spatial–temporal constraints for monitoring permafrost deformation. The method establishes a segmented permafrost deformation model considering the interannual variation in deformation over time. The spatial similarity constraint is subsequently introduced to establish the relationship between deformations at neighboring points, improving the results of permafrost monitoring. Both simulated and real experiments confirmed the ability of the proposed method to capture interannual variations in permafrost deformation with higher accuracy and point density. A real experiment with Sentinel-1 data revealed significant interannual variations in surface deformation within the Wudaoliang-Tuotuohe permafrost region from 2018–2021, characterized by decreased linear deformation and slight seasonal deformation changes. Compared with the traditional methods and in-situ data, the deformation accuracy and point density can be improved by approximately 15.6% and 19.4%, respectively.

Given that the Qinghai-Tibet Plateau (QTP) is an important ecological security barrier in western China, changes in its ecosystem services (ESs) have received attention. Using multivariate datas and model simulations, we evaluated the ESs of the QTP, revealed their driving factors, and constructed ecological conservation pattern based on ecosystem services index (ESI) and ecosystem sensitivity (ES). The results showed that: (1) The overall ESs of the QTP from 2000 to 2020 were positive, with a spatial distribution characteristic of decreasing from southeast to northwest. Forest and grassland were the key land use types promoting ESs. (2) Natural factors had a stronger influence on ESs than socioeconomic factors, with precipitation, FVC (Fractional Vegetation Cover) and NPP (Net Primary Productivity) had the strongest explanatory power for ESs. (3) The proportion of the collaborative development area (CDA), consolidation and enhancement area (CEA) and priority protection area (PPA) to the total area of the QTP was 19%, 56% and 25% respectively. The CDA should follow the concept of natural restoration and green development. The CEA should optimize the management system and do a good job of environmental management in combination with artificial restoration. The PPA should strictly prevent disturbances caused by human activities and protect the originality of natural landscapes such as glaciers, snow and permafrost.

The establishment of nature reserves (NRs) is widely acknowledged as one of the most effective measures to mitigate the threats on habitat quality (HB) posed by human activities (HAs). Precise and scientific assessment of the effectiveness of NRs holds crucial significance in improving management and promoting conservation. In this study, key indicators were creatively selected and applied to the propensity score matching (PSM) model to comprehensively assess the variations in HAs and HB within national NRs on the Qinghai-Tibet Plateau. The results indicated that between 2000 and 2020, 67.4 % of the NR area experienced a decline in HA-related impacts, while 53.8 % of the area saw improvements in HB. Additionally, with the exclusion of external environmental factors, in 2020, the difference in HAs and HB between NRs and non-protected areas was −0.131 and 0.179, respectively. Finally, based on an assessment of the overall conservation effectiveness, seven NRs were classified as “Class I'', 18 as “Class II'', and another seven as “Class III''. These results not only confirmed the effectiveness of national NRs in alleviating anthropogenic pressure and enhancing HB but also served as an important basis for accurately assessing the conservation effectiveness of other NRs and formulating more scientifically sound and appropriate management policies.

Background Plant species diversity is of great significance to maintain the structure and function of the grassland ecosystem. Analyzing community niche and interspecific associations is crucial for understanding changes in plant species diversity. However, there are few studies on the response of plant species diversity, species niche characteristics, and interspecific relationships to nitrogen addition in alpine meadows on the Qinghai-Tibet Plateau. Methods This study investigates the effects of different levels of nitrogen addition (0, 15, 30, 45, and 60 g N m−2) on plant species diversity, functional group importance values, niche width, niche overlap, and interspecific associations in an alpine meadow. Results 1) Compared with the control (CK), the Shannon-Weiner index and species richness index significantly increased by 11.36% and 30.77%, respectively, with nitrogen addition at 30 g N m−2, while both indices significantly decreased by 14.48% and 23.08%, respectively, at 60 g N m−2. As nitrogen addition increased, the importance value of grasses showed an upward trend, whereas the importance value of sedges showed a decline. 2) The niche width of Poa pratensis L., Elymus nutans Griseb., and Stipa purpurea Griseb. are increased with higher nitrogen addition. As nitrogen addition increases, the niche overlap values also show a rising trend. At 60 g N m−2, the overall community association in the alpine meadow exhibited a significant negative correlation. These findings suggest that grasses exhibit strong ecological adaptability under high nitrogen addition and gain a competitive advantage in spatial competition, increasing their niche width. Moreover, as nitrogen levels increase, the importance values of grasses rise significantly, and their ecological characteristics become more similar, resulting in reduced niche overlap among plant species. Furthermore, high nitrogen addition intensifies interspecific competition between grasses, sedges, and forbs, disrupting the original balance and reducing species diversity. These insights provide a valuable understanding of changes in species diversity and competitive dynamics in alpine meadow plant communities under high nitrogen addition.

As global climate change intensifies, understanding the response mechanisms and adaptive capacities of ecosystems to climate change has become a core focus in environmental science. The Qinghai-Tibet Plateau (QTP), a region highly sensitive to global climate change, shows vegetation phenological shifts that reflect the ecosystem’s response to climate fluctuations. However, how phenological metrics extracted from different vegetation indices affect our understanding of these shifts in the region remains unclear. This study analyzes the start (SOS) and end (EOS) of the growing season on the QTP from 1982 to 2015 using GIMMS NDVI3g data. These metrics were compared with phenological data derived from GIMMS LAI3g and MODIS EVI2 data. The results indicate that phenological metrics derived from different vegetation indices (NDVI, LAI, and EVI2) are generally consistent in their spatiotemporal distribution and show significant correlations. However, regional differences and temporal inconsistencies were observed. This comparative analysis reveals the strengths and limitations of various vegetation indices in phenological metric extraction. The results offer crucial insights for enhancing the precision of phenological modeling and highlight the significance of choosing suitable vegetation indices in future studies on phenology.

Industrial parks in China are centers of intensive chemical manufacturing and other industrial activities, often concentrated in relatively small areas. This concentration increases the risk of soil pollution both within the parks and in surrounding areas. The soils of the Tibetan Plateau, known for their high sensitivity to environmental changes, are particularly vulnerable to human activity. In this study, we examined the concentrations (mg/kg) of 10 metal elements (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Se, and Zn) in soils at depths of 0–10 cm, 10–20 cm, and 20–30 cm from the surface at three distances (500 m, 1000 m, and 1500 m from the park boundary) on the east, south, west, and north sides of the Tianzhu Industrial Park on the Qinghai-Tibet Plateau. The concentrations of As, Cr, Mn, and Pb were close to the standard reference values for the Qinghai-Tibet Plateau, while Cu, Ni, Se, and Zn levels were found to be 1.6-2.2 times higher than the reference values. Cd and Hg concentrations were particularly concerning, at 8.0 and 6.5 times higher than reference values, respectively. The potential ecological risk indexes indicated persistent risk levels for Cd and Se across various directions and distances. Variations in soil depth and direction were observed for the concentrations of As, Cd, Hg, Pb, Se, and Zn, underscoring the need for regular or long-term monitoring. Cd, in particular, presents a significant hazard due to its high concentration and its propensity for uptake by plants in the study area.

Despite playing a fundamental role in plant population dynamics, the considerable variability and control of belowground bud banks in grasslands currently remain unknown globally. Here, we explored the size and driver of belowground bud bank both in alpine (Qinghai-Tibet Plateau: QTP) and temperate (Inner Mongolia Plateau: IMP) grasslands across China, using a dataset comprising 209 observations at 171 sites compiled from laboratory and published data. We found that temperate grassland had higher density (912 no./m2) dominated by tiller buds (72.26 %) than alpine grasslands (768 no./m2) dominated by rhizome buds (51.56 %). Moreover, belowground bud of alpine grassland exhibited longitudinal, latitudinal and altitudinal patterns, more diverse than those of longitudinal and latitudinal pattern in temperate grassland. Furthermore, climate, particularly the precipitation, is the factor controlling belowground bud in alpine grassland, while soil nutrient predominantly controls those in temperate grassland. Our study advances understanding of the variability and its climate and soil regulation on belowground buds in grasslands, sheds new light on differing management respectively for alpine and temperate grasslands in the context of climate change.

IntroductionThe Qinghai-Tibet Plateau holds a significant position in the global ecosystem, with its unique high altitude and complex geographical features fostering rich biodiversity. The plateau’s high-altitude environment and distinctive climate system significantly influence the Asian monsoon and regional hydrological cycles. Its vast glaciers and snow reserves are crucial in regulating the Asian climate. While previous studies have analyzed the habitat quality of the Qinghai-Tibet Plateau, significant variations exist across different vegetation ecoregions, warranting further investigation into these variations and their influencing factors.MethodsThis study conducted a comprehensive assessment of habitat quality on the Qinghai-Tibet Plateau by analyzing the impacts of human activities, climate change, and grazing intensity. Using the InVEST Model and Geodetector Model, we evaluated habitat quality across the plateau’s six vegetation ecoregions from 2000 to 2020. The efficacy of ecological red-line policies in actual conservation efforts was also examined.ResultsThe results indicate that habitat quality among vegetation ecoregions is shaped by a complex interaction of geographical and human-induced factors, leading to notable spatiotemporal variations. From 2000 to 2020, the quality of habitats was significantly impacted by human activities, climate change, grazing intensity, and land-use changes. These effects were especially prominent during the period from 2005 to 2010.DiscussionThe changes in habitat quality on the Qinghai-Tibet Plateau are influenced by multiple driving factors, with significant differences in the drivers across various vegetation ecoregions. The ecological redline policy has played an important role in protecting the ecological environment in key areas, particularly in regions with high human intervention, where its effectiveness is more pronounced. In future ecological management, it is essential to strengthen conservation measures based on regional specificity. By comprehensively considering the impact of human activities and natural factors, developing more targeted management strategies is crucial for improving habitat quality.

Abstract Background The geographic patterns of plant diversity in the Qinghai-Tibet Plateau (QTP) have been widely studied, but few studies have focused on wetland plants. This study quantified the geographic patterns of wetland plant diversity in the QTP through a comprehensive analysis of taxonomic, phylogenetic and functional indices. Methods Based on a large number of floras, monographs, specimens and field survey data, we constructed a comprehensive dataset of 1,958 wetland plant species in the QTP. Species richness (SR), phylogenetic diversity (PD), functional diversity (FD), net relatedness index (NRI) and net functional relatedness index (NFRI) were used to assess the taxonomic, phylogenetic and functional diversity of wetland plants. We explored the relationships between the diversity indices and four categories of environmental variables (i.e. energy-water, climate seasonality, topography and human activities). We used four diversity indices, namely endemic species richness, weighted endemism, phylogenetic endemism and functional endemism, together with the categorical analysis of neo- and paleo-endemism (CANAPE), to identify the endemic centers of wetland plants in the QTP. Results SR, PD and FD were highly consistent and showed a decreasing trend from southeast to northwest, decreasing with increasing elevation. The phylogenetic structure of wetland plant assemblages in most parts of the plateau is mainly clustered. The functional structure of wetland plant assemblages in the southeast of the plateau is overdispersed, while the functional structure of wetland plant assemblages in other areas is clustered. Energy-water and climate seasonality were the two most important categories of variables affecting wetland plant diversity. Environmental variables had a greater effect on the functional structure of wetland plants than on the phylogenetic structure. This study identified seven endemic centres, mainly in the Himalayas and Hengduan Mountains. Conclusions Climate and topography are the main factors determining the geographic distribution of wetland plant diversity at large scales. The majority of grid cells in the QTP with significant phylogenetic endemism were mixed and super-endemism. At large scales, compared to climate and topography, human activities may not have a negative impact on wetland plant diversity in the QTP.

Abstract Background Gut microbiota is pivotal in regulating hosts' biological processes and maintaining homeostasis, but knowledge about its role in wild herbivores in extreme environments remains limited. Methods Gut bacteria and fungi were sequenced in ruminant (Chiru and Yak) and nonruminant (Kiang) herbivores on the Qinghai–Tibet Plateau, and their community structure, co‐occurrence networks, functions, and assembly mechanisms were investigated using multivariate ecological and statistical methods. Results Kiang had lower gut microbial diversity than Chiru and Yak. Bacterial host‐specific exclusivity was greater than that of fungi. In addition to the evidence of glycan biosynthesis and carbohydrate metabolism, Chiru had a high Firmicutes/Bacteroidetes ratio and low animal pathogen abundance, suggesting better adaptation to the plateau's harsh environment. Additionally, members of gut microbiota tended to co‐occur rather than co‐exclude in all herbivores. Different network complexity and stability patterns were observed between bacterial and fungal communities. Furthermore, gut bacterial assembly was primarily controlled by stochastic dispersal limitation and drift, whereas fungal assembly was primarily controlled by deterministic homogeneous selection except in Chiru. Conclusions On the Qinghai–Tibet Plateau, Chiru and Yak exhibit more diverse gut microbiota and more diverse metabolic functions than Kiang, and gut bacteria are more divergent than gut fungi in these herbivores.

[Objective] The lakes of the Tibetan Plateau are important indicators of climate change, and their expansion or contraction also have an important impact on the natural environment of the Tibetan Plateau. [Methods] Three typical lakes located in different climatic sub-regions of the Qinghai-Tibet Plateau (Qinghai Lake, Yangzhuo Yongcuo, and Ulan Ula Lake) were selected to study the temporal and spatial variation of the hydrological characteristics of the three typical lakes from 1985 to 2021 by remote sensing monitoring methods, to reveal the role of key climatic factors, and to further explore the influence of glaciers and permafrost on the typical lakes. [Results] The area and water level of Qinghai Lake showed a significant upward trend, with an area increase of 238.68 km2 and a water level increase of 1.32 m. In space, it showed a trend of expansion in the east-west direction. The area and water level of Yangzhuo Yongcuo Lake first fluctuated and then decreased, decreasing by 16.31 km2 and 3.25 m respectively. In space, the overall area showed a shrinking trend from the surrounding to the center. The area and water level of Ulan Ula Lake showed a significant upward trend, increasing by 125.57 km2 and 8.12 m, respectively, and the expansion area was mainly concentrated in the south. [Conclusion] The analysis of key climate factors shows that the lake expansion caused by the increase of precipitation and the accelerated melting of glacial permafrost in the warm and humid environment is the most prominent environmental change characteristics of the Qinghai-Tibet Plateau. The main reason for the rise in the water level of Ulan Ula Lake is the seasonal thaw of permafrost caused by rising temperatures. Exploring the changes in lake area on the Tibetan Plateau is of great guiding significance for in-depth research on global climate change and surface water resource assessment.

Abstract Wildfires, as an environmental filter, are pivotal ecological disturbances that reshape plant communities and soil dynamics, playing a crucial role in regulating biogeographic patterns and ecosystem services. In this study, we aim to explore the effects of wildfires on forest ecosystems, specifically focusing on the plant-soil feedback mechanisms within the northeastern margin of the Qinghai-Tibet Plateau (QTP). Utilizing Partial Least Squares Path Modeling (PLS-PM), we investigated the interrelationships among soil physicochemical properties, enzyme activities, species diversity, and community stability at varying post-fire recovery stages (5, 15, and 23 years). Results indicated that in the early recovery stages, rapid changes in soil properties such as decreased pH (p

Eremurus was described at the beginning of the 19th century. However, due to limited sampling and the small number of gene markers to date, its phylogeny and evolution are largely unknown. In this study, we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus, which are found in Central Asia (its center of diversity) and China. We also analyzed nuclear DNA ITS of 33 species, encompassing all subgenera and sections of the genus in Central Asia, southwest Asia and China. Our findings revealed that the genus was monophyletic, although both subgenera Eremurus and Henningia were found to be paraphyletic. Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus. Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene. Diversification of Eremurus occurred from the early Oligocene to the late Miocene. Paratethys Sea retreat and several orogenetic events, such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts (Altai, Pamir, Tian Shan), caused serious topographic and climate (aridification) changes in Central Asia that may have triggered a split of clades and speciation. In this transformed Central Asia, speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic, topographic and soil conditions that exist in this region.

Abstract Morchella spongiola is a highly prized mushroom for its delicious flavor and medical value and is one of the most flourishing, representative, and dominant macrofungi in the Qilian Mountains of the Qinghai-Tibet Plateau subkingdoms (QTPs). However, the understanding of M. spongiola remains largely unknown, and its taxonomy is ambiguous. In this study, we redescribed a unique species of M. spongiola, i.e., micromorphology, molecular data, genomics, and comparative genomics, and the historical biogeography of M. spongiola were estimated for 182 single-copy homologous genes. A high-quality chromosome-level reference genome of M. spongiola M12-10 was obtained by combining PacBio HiFi data and Illumina sequencing technologies; it was approximately 57.1 Mb (contig N50 of 18.14 Mb) and contained 9775 protein-coding genes. Comparative genome analysis revealed considerable conservation and unique characteristics between M. spongiola M12-10 and 32 other Morchella species. Molecular phylogenetic analysis indicated that M. spongiola M12-10 is similar to the M. prava/Mes-7 present in sandy soil near rivers, differentiating from black morels ~ 43.06 Mya (million years ago), and diverged from M. parva/Mes-7 at approximately 12.85 Mya (in the Miocene epoch), which is closely related to the geological activities in the QTPs (in the Neogene). Therefore, M. spongiola is a unique species rather than a synonym of M. vulgaris/Mes-5, which has a distinctive grey-brown sponge-like ascomata. This genome of M. spongiola M12-10 is the first published genome sequence of the species in the genus Morchella from the QTPs, which could aid future studies on functional gene identification, germplasm resource management, and molecular breeding efforts, as well as evolutionary studies on the Morchella taxon in the QTPs.

Abstract Tibetan Buddhist monasteries are widely distributed throughout the Qinghai–Tibet Plateau and are significant locations for human–wildlife coexistence. Given the significance of their historical and contemporary social influence, it is crucial to ascertain whether there exists a non‐negligible correlation between these monasteries and their surrounding wildlife. In contrast to sacred mountains and lakes, there have been few studies that have examined the relationship between Tibetan Buddhist monasteries and wildlife communities. Using birds as a model ecological community, generalized mixed effect models (GLMM) were employed to examine relationships between the presence of Tibetan Buddhist monasteries and the number of individuals (relative abundance), avian species richness and diversity, using data from bird‐watching checklists (n = 262) obtained from the China Bird Report. Our models also included landscape‐wide environmental factors, including the ratio of woodland habitat, grassland habitat and open habitats, human footprint index, distance to nearest human occupation (villages), distance to water, altitude, time, presence of monastery and their interactions. Observation time was included as a model covariate. The presence of Tibetan Buddhist monasteries and the interactions between the presence of monasteries and environmental variables exhibit a significant correlation with the number of individual birds recorded (relative abundance), but not with observed species richness or diversity. Moreover, the relative abundance of birds was found to be significantly higher in areas around monasteries compared to those without monasteries. The abundance of species from eight families, namely Accipitridae, Corvidae, Columbidae, Passeridae, Leiothrichidae, Friningillidae, Musciapidae and Turidae, was significantly positively correlated with the presence of monasteries. Notably, the positive correlation of Accipitridae with the presence of celestial burial grounds around monasteries suggests a relationship between celestial burial practices and Accipitridae abundance at these sites. Our study reveals a significant positive correlation between Tibetan Buddhist monasteries and aspects of avian community composition in the eastern Qinghai–Tibetan Plateau, thus highlights their potential role in the preservation of avian populations in fragmented landscape habitats. We encourage the government and relevant national parks stakeholders to implement targeted management strategies that take into account the unique patterns of human–wildlife coexistence in these areas, and to leverage the cultural advantages of the region to promote ecological conservation. Read the free Plain Language Summary for this article on the Journal blog.

Permafrost is degrading globally, particularly those with low thermal stability on the Qinghai‒Tibet Plateau, owing to climate change. However, the inadequacy of direct research on permafrost degradation based on in-situ monitoring limits the prediction of permafrost degradation and engineering practices. This study explored the processes and modes of permafrost degradation into talik by analyzing ground temperature data from five points in the hinterland of the Qinghai‒Tibet Plateau from 2006 to 2021. The results showed that the degradation of the warm permafrost layer with a geothermal gradient of zero occurred simultaneously in the top and bottom directions. The rate of permafrost degradation from the top down and bottom up increase during the degradation process, but the increase of the former is more drastic after the formation of thawed interlayer. Additionally, the construction of the Qinghai‒Tibet Railway changed the degradation modes of the permafrost in adjacent natural sites through horizontal heat transfer, particularly after through talik formation under the embankment. The findings suggest that taking countermeasures before or immediately after forming thawed interlayer is more effective. When evaluating the thermal impact of projects in warm permafrost regions, special attention should be given to the horizontal heat transfer process that may result from the formation of a through talik.

Jiulong is located on the east side of the Qinghai-Tibet Plateau (QTP) and is a region prone to southwest vortex. Cloud detection with new-type detection equipment in this region helps enhance the knowledge of cloud characteristics in the southwest vortex-prone region. In this study, based on the ground-based microwave radiometer data from June to August of 2018-2019 in Jiulong, the observational characteristics of cloud occurrence frequency (COF), liquid water path (LWP), and supercooled liquid water path (SLWP) for non-precipitating clouds during the summer seasons are investigated. The results are as follows. The monthly average COF of summer non-precipitating clouds in Jiulong is between 67%-82%, with low and middle clouds being the main types, and high clouds being less common. For low clouds, the COF is low in daytime and high in nighttime, while it is the opposite for middle and high clouds. The vertical distribution of COF presents an unimodal pattern, with a peak of 8.1% at a height of about 2 km. Due to the diurnal variation of atmospheric thermal stratification, the unimodal pattern of COF shows diurnal differences. Moreover, the average LWP of summer non-precipitating clouds in Jiulong is 0.433 kg·m-2, with the average LWPs of low, middle, and high clouds being 0.665, 0.240, and 0.102 kg·m-2, respectively. The diurnal variation of LWP in low clouds is similar to their COF, while the diurnal variations of LWP in middle and high clouds are not significant. Additionally, the average SLWP of cold clouds among summer non-precipitating clouds in Jiulong is 0.154 kg·m-2, with the average SLWPs of low, middle, and high clouds being 0.065, 0.166, and 0.102 kg·m-2, respectively. On the whole, the proportion of SLWP in LWP is about 34.3%-38.8%. The proportion of SLWP increases with the height of the cloud, which makes the diurnal variations of SLWP in middle and high clouds similar to that of LWP. Compared with central China, the characteristics of summer non-precipitating clouds in Jiulong are significantly different, and this is closely related to the different characteristics of atmospheric water vapor between the two regions.

Objective The Qinghai-Tibet Plateau is one of the most seismically active regions along the Mediterranean-Himalayan seismic belt. Understanding the earthquake-controlling effect of the active tectonic system in this region is crucial for analyzing regional strong earthquake hazards. Methods We analyzed earthquake activity with MW≥6.0 since 1990 and their tectonic mechanism around the Tibetan Plateau, focusing on the continental collision-extrusion tectonic system. Results The results show that the system plays a significant role in governing regional strong earthquake activity. Specifically, MW≥6.5 earthquakes primarily occur along the main boundary fault zone of this tectonic system, exhibiting a relatively regular spatio-temporal migration process. Moreover, the multi-layered extrusion-rotation active tectonic system in the eastern Tibetan Plateau constitutes the primary earthquake-controlling structure of the strong earthquake process since 1990, followed by the thrust faults of the Himalayan foreland. Therefore, the extrusion tectonic system of the Qinghai-Tibet Plateau should be the focus for the trend analysis of the strong earthquake activity in the future, especially the most active secondary extrusion tectonic units such as the Bayan Har block. Comparative analysis of strong earthquake activities in and around the Anatolian plate reveals similar continental collision-extrusion tectonic systems and earthquake-controlling effects in this area, indicating that this tectonic system is a typical earthquake-controlling structure in the intracontinental orogenic belt. Conclusion Further comprehensive analysis suggests that the active tectonic system can significantly control regional strong earthquake activity. Firstly, most of the strong earthquake events occur in the main boundary fault zone of the fault block in the tectonic system. Secondly, the strong earthquake events along different structural zones in the tectonic system often have linkage effects or mutual triggering relationships, and the complex or particular structural sites are often where double earthquakes or earthquake swarm activities easily occur. Thirdly, when a certain structural unit or tectonic zone in the tectonic system is in an active stage, strong earthquake clustering phenomena occur. Significance A thorough understanding of the coordinated deformation relationships between major active faults in the tectonic system, the segmented rupture behavior of strong earthquake activity in active fault zones, and the characteristics of "long period, quasi-periodicity and clustering" of strong earthquake recurrence in situ on active faults will assist in more accurately assessing the future seismic hazard of active fault zones when analyzing the future trend of strong earthquake activity based on the active tectonic system.

Global climate change has accelerated the reduction of permafrost regions across different altitude gradients, shortening the duration of the freezing period to varying extents. However, the response of the soil microorganisms of frozen soils along altitude gradients remains unclear. In this study, we employed 16S rRNA sequencing and LC-MS metabolomics to investigate the response of soil microbial communities and soil metabolites to vertical stratification in the permafrost soils of the Qinghai Lake region. The results indicated that Proteobacteria, Firmicutes, and Actinobacteria were key soil bacterial phyla in the permafrost soils of Qinghai Lake during the freezing period, with Proteobacteria and Firmicutes showing significant sensitivity to vertical stratification (p < 0.05). The majority of the physicochemical factors exhibited a trend of initially increasing and then decreasing with increasing altitude, whereas pH showed the opposite trend. pH and moisture content were identified as the most important environmental factors influencing soil bacterial community structure. Deterministic processes dominated the assembly of bacterial communities of frozen soils in the Qinghai Lake basin. Co-occurrence network analysis showed that increasing altitude gradients led to a higher average degree of the bacterial network, while reducing network complexity and inter-species connectivity. Soil metabolomics analysis revealed that vertical stratification altered the metabolic profiles of 27 metabolites, with the significantly changed metabolites primarily associated with carbohydrate and amino acid metabolism. In conclusion, the characteristics of the Qinghai Lake permafrost were regulated by regional vertical stratification, which further influenced microbial community structure and soil metabolic characteristics, thereby altering carbon and nitrogen stocks. Specifically, higher altitudes were more favorable for the retention of the carbon and nitrogen stocks of frozen soils in the Qinghai Lake basin.

This study aimed to isolate lactic acid bacteria (LAB) with strong antioxidant activity and potential probiotic properties from yak milk and dairy products in the Qinghai–Tibet Plateau. Initial screening of the isolates was performed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay and a hydrogen peroxide tolerance test. Subsequently, the antioxidant capacity of the isolates was assessed through five distinct assays: 2,2′-azino-bis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging ability, superoxide anion radical scavenging ability, hydroxyl radical scavenging ability, a DPPH scavenging assay, and a reducing activity assay. The strains with the stronger antioxidant potential were then further evaluated for their probiotic properties. Whole-genome sequencing was conducted on Lactobacillus plantarum QL01. Among 1205 isolates, 9 strains exhibited potential antioxidant capabilities. Following probiotic property evaluation, QL01 was identified as a safe candidate due to its strong growth, strong adhesion ability, and resilience to acidic, bile, and simulated gastrointestinal conditions. Genome analysis revealed that most of QL01’s genes were involved in carbohydrate metabolism. Further examination of antibiotic resistance and virulence factors confirmed its safety, meanwhile genes linked to adhesion and stress responses underscored its probiotic potential. In conclusion, QL01, a strong antioxidant strain, was successfully isolated, and its probiotic potential was confirmed through comprehensive in vitro and genomic analyses.

The accurate modeling of complex freeze–thaw processes and hydrothermal dynamics within the active layer is challenging. Due to the uncertainty in hydrothermal simulation, it is necessary to thoroughly investigate the parameterization schemes in land surface models. The Noah-MP was utilized in this study to conduct 23,040 ensemble experiments based on 11 physical processes, which were aimed at improving the understanding of parameterization schemes and reducing model uncertainty. Next, the impacts of uncertainty of physical processes on land surface modeling were evaluated via Natural Selection and Tukey’s test. Finally, Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was used to identify the optimal combination of parameterization schemes for improving hydrothermal simulation. The results of Tukey’s test agreed well with those of Natural Selection for most soil layers. More importantly, Tukey’s test identified more parameterization schemes with consistent model performance for both soil temperature and moisture. Results from TOPSIS showed that the determination of optimal schemes was consistent for the simulation of soil temperature and moisture in each physical process except for frozen soil permeability (INF). Further analysis showed that scheme 2 of INF yielded better simulation results than scheme 1. The improvement of the optimal scheme combination during the frozen period was more significant than that during the thawed period.

The unique tourism resources of the Qinghai-Tibet Plateau have created conditions for the development of ecotourism, while the existence of attractions may also have positive and negative impacts on the surrounding environment. This study defines the radiation waves that generate ecological effects as “ecological waves”, quantifies the ecological waves of attractions by buffer zone analysis of the normalized difference vegetation index (NDVI) within 20 km of 38 4A and 5A attractions on the Qinghai-Tibet Plateau in 2020, and elaborately explores the ecological effects of attractions on the surrounding environment. By combining the principle of ripple effects, it analyzes the impact of urban attractions on urban vegetation environments. The study found that attractions on the Qinghai-Tibet Plateau have a positive ecological effect on the surrounding vegetation, the positive ecological effect of suburban attractions has a distance threshold, effectively promoting vegetation greenness within a range of 6–14 km, and the ecological effect disappears beyond 14 km. In addition, applying the ripple effect model to urban attractions and city centers (Xining and Lhasa), the results indicated that among the five urban attractions in Xining, Kumbum Monastery, Qinghai Tibetan Culture Center, and Country Farming Ecological Park (with distance restrictions of 2–20 km) have significant positive ecological effects within the built-up area, while the ecological effects of Qinghai Province Museum and Qinghai-Tibetan Plateau Safari Park are not significant. The positive ecological effects of the five urban attractions in Lhasa within the built-up area are not significant, and different attractions have different distance thresholds for ecological effects. Furthermore, this study found that attractions in Qinghai have a better ecological foundation around them than attractions in Tibet, making them more suitable for the development of ecotourism. This study has opened up a new perspective on the ecological effects of attractions and provided scientific references for the development of ecological tourism in the Qinghai-Tibet Plateau.

Introduction: Grassland-livestock balance is an important principle of sustainable development of grassland livestock production and grassland ecosystem health. Grassland degradation becomes more serious at global scales and especially at the area that is sensitive to climate change and human activities. Decreases in pasture biomass and shifts in plant community composition in degraded grasslands can largely affect grazing behaviors of livestock. Up to date, however, it is unclear that whether livestock behaviors change across spatial and temporal scales and what key factors are to shape observed behavioral patterns of livestock. Methods: Here, yak behaviors including grazing, rumination and walking on the eastern Qinghai-Tibetan Plateau (QTP) were monitored by a continuous visual observation, to investigate temporal and spatial variations of grazing behavior of yaks (Bos grunniens); based on the data from public database in the past 18 years, a meta-analysis was conducted to examine the main factors that affect grazing behaviors and intake of yaks. Results: We showed that grazing behaviors of yaks differed significantly within hours, among hours of each day and among days as well as across different observation sites. Intake rate of yaks was higher in the morning than in the afternoon, but walking speed showed an inverse trend compared with intake rate. Resting, altitude, the mean annual precipitation (MAP), the mean annual temperature (MAT), forage ash, yak age and season were the main predictors for yak intake, and forage and yak individual characteristics had direct effects on grazing behaviors and intake of yaks. Discussion: The findings confirm that grazing behaviors of yaks can vary even at small temporal scales and regional scales, which is closely related to the shift in forage quality and biomass caused by environmental changes. The study suggests that multiple factors can be responsible for the variation in livestock behaviors and shifts in behavioral patterns may consequently lead to positive or negative feedback to grassland ecosystems through plant-animal interactions. [ABSTRACT FROM AUTHOR]