The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tec...The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tectonic evolution remain poorly understood due to limited geophysical data in this region.In this study,we computed cross-correlations for the TT components of station-pairs with high signal-to-noise ratios to extract Love wave waveforms and further performed Lovewave ambient noise tomography to image the upper crustal shear-wave velocity structure of the Kumkol basin down to 10 km depth.Our seismic velocity model reveals that the Kumkol Basin has a sedimentary thickness exceeding 8 km,with its center located near the Arka Mountain on the southern side.This suggests that the basin was likely formed as a foreland basin in response to the uplift of the Qiman Tagh Mountain to the north.Additionally,integrated with seismic reflection data,our seismic velocity model images a detachment fault at the basin basement depth.We inferred that the Kumkol Anticlinorium at the basin’s center have been produced by multiple thrust faults converging into this detachment fault at 8–10 km depth following the Early to Middle Miocene uplift of the Qiman Tagh Mountain.This structural configuration indicates pulsed basinward deformation since the late Miocene,likely reflecting a tectonic regime shift from extrusion to distributed shortening in the northern Qinghai-Xizang Plateau.Our findings provide a high-resolution velocity model of the Kumkol Basin,offering critical insights into its structural evolution and supporting future resource exploration in this underexplored region.展开更多
The Qinghai-Xizang Plateau(QXP)serves as a crucial ecological barrier in China and Asia,exerting profound influences on global climate and biodiversity conservation.Gannan Tibetan Autonomous Prefecture(hereinafter ref...The Qinghai-Xizang Plateau(QXP)serves as a crucial ecological barrier in China and Asia,exerting profound influences on global climate and biodiversity conservation.Gannan Tibetan Autonomous Prefecture(hereinafter referred as Gannan Prefecture),located on the northeastern edge of the QXP,represents a fragile alpine ecosystem in which land use change significantly impacts ecosystem services(ESs).This study established a comprehensive framework,utilizing the Patch-generating Land-Use Simulation(PLUS)model coupled with the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model to predict land use patterns under the natural development scenario,cultivated land protection scenario,and ecological protection scenario for Gannan Prefecture by 2030 and evaluated four critical ESs:habitat quality(HQ),water yield(WY),soil retention(SR),and carbon storage(CS).The primary aim is to elucidate the impacts of dynamic land use change on ESs.The results revealed that,from 2000 to 2020,HQ exhibited minimal variation,whereas CS experienced a slight decline.Conversely,WY and SR showed significant improvements.Under the natural development scenario,construction land was projected to increase by 4247.74 hm^(2),primarily at the expense of forest land.The cultivated land protection scenario anticipated an increase in farmland by 2634.36 hm^(2),which was crucial for maintaining food security.The ecological protection scenario predicted a notable expansion of forest land,accompanied by a restrained development rate of construction land.The ecological protection scenario also showed an increase in the ecosystem service index(ESI),encompassing 26.07%of the region.Forest land and grassland emerged as the primary contributors to ESs,while construction land substantially impacted WY.Water bodies exhibited minimal contribution to ESs.This study enhanced the understanding of land use change impacts on ESs in fragile and high-altitude ecosystems,offering essential theoretical frameworks and practical direction for forthcoming ecological policy and regional planning endeavors.展开更多
The Qinghai-Xizang Plateau of China faces challenges like thaw slumping,threatening slope stability and infrastructure.Understanding the mechanical properties of the roots of the dominant herbaceous plant species in t...The Qinghai-Xizang Plateau of China faces challenges like thaw slumping,threatening slope stability and infrastructure.Understanding the mechanical properties of the roots of the dominant herbaceous plant species in the alpine meadow layer of the permafrost regions on the Qinghai-Xizang Plateau is essential for evaluating their role in enhancing soil shear strength and mitigating slope deformation in these fragile environments.In this study,the roots of four dominant herbaceous plant species—Kobresia pygmaea,Kobresia humilis,Carex moorcroftii,and Leontopodium pusillum—that are widely distributed in the permafrost regions of the Qinghai-Xizang Plateau were explored to determine their mechanical properties and effects in enhancing soil shear strength.Through indoor single root tensile and root group tensile tests,we determined the root diameter,tensile force,tensile strength,tensile ratio,and strength frequency distributions.We also evaluated their contributions to inhibiting slope deformation and failure during the formation and development of thermal thaw slumps in the alpine meadow.The results showed that the distribution of the root diameter of the dominant plant species is mostly normal,while the tensile strength tends to be logarithmically normally distributed.The relationship between the root diameter and root tensile strength conforms to a power function.The theoretical tensile strength of the root group was calculated using the Wu-Waldron Model(WWM)and the Fiber Bundle Model(FBM)under the assumption that the cumulative single tensile strength of the root bundle is identical to the tensile strength of the root group in the WWM.The FBM considers three fracture modes:FBM-D(the tensile force on each single root is proportional to its diameter relative to the total sum of all the root diameters),FBM-S(the cross-sectional stress in the root bundle is uniform),and FBM-N(each tensile strength test of individual roots experiences an equal load).It was found that the model-calculated tensile strength of the root group was 162.60%higher than the test value.The model-derived tensile force of the root group from the FBM-D,FBM-S,and FBM-N was 73.10%,28.91%,and 13.47%higher than the test values,respectively.The additional cohesion of the soil provided by the roots was calculated to be 25.90-45.06 kPa using the modified WWM,67.05-38.15 kPa using the FBM-S,and 57.24-32.74 kPa using the FBM-N.These results not only provide a theoretical basis for further quantitative evaluation of the mechanical effects of the root systems of herbaceous plant species in reinforcing the surface soil but also have practical significance for the effective prevention and control of thermal thaw slumping disasters in the permafrost regions containing native alpine meadows on the Qinghai-Xizang Plateau using flexible plant protection measures.展开更多
Antibiotic resistance genes(ARGs)are increasingly recognized as a global public health threat,with glaciers acting as reservoirs for ARGs transported via atmospheric pathways.Warming climate accelerates glacier meltin...Antibiotic resistance genes(ARGs)are increasingly recognized as a global public health threat,with glaciers acting as reservoirs for ARGs transported via atmospheric pathways.Warming climate accelerates glacier melting,releasing ARGs into downstream environments,posing ecological health and sustainable aquatic ecosystem development challenges.However,the distribution profiles of ARGs and their risks in glaciers from the polar region remain unclear.This study used 294 metagenomic sequences to investigate the distribution and risks of ARGs in glaciers across the Qinghai-Xizang Plateau,Antarctica,and the Arctic regions and compared them with adjacent and anthropogenically impacted environments.Among the three glacier regions studied,the Qinghai-Xizang Plateau exhibited the highest abundance of ARGs,whereas Antarctica displayed the lowest.ARG abundance in adjacent environments was comparable to that in the glaciers of the Qinghai-Xizang Plateau,but in the anthropogenically impacted environment,it was significantly higher than in glaciers.A shared resistome was identified in glaciers,dominated by bacitracin,multidrug,and macrolide-lincosamide-streptogramin(MLS)resistance genes.The bacA gene,which is related to bacitracin resistance,was the most common subtype,indicating that it is naturally present in microbial communities of glaciers.Risk assessments showed that 74.1%–78.9%of ARGs were low-risk in the Qinghai-Xizang Plateau and polar glaciers,indicating minimal human influence.However,7.3%–8.0%were classified as high-risk,posing potential threats through horizontal gene transfer(HGT)and the spread of multidrug-resistant pathogens.These findings highlight the need to monitor ARGs in glacier environments,as climate change accelerates glacier melting and subsequent release of ARGs into downstream ecosystems.展开更多
Strong sensitivity of satellite microwave remote sensing to the change of surface dielectric properties,as well as the insensitivity to air pollution and solar illumination effects,makes it very suitable for monitorin...Strong sensitivity of satellite microwave remote sensing to the change of surface dielectric properties,as well as the insensitivity to air pollution and solar illumination effects,makes it very suitable for monitoring freeze-thaw conditions.The freeze-thaw cycle changes in the Qinghai-Xizang Plateau have an important impact on the ecological environment and infrastructure.Based on the Scanning Multi-channel Microwave Radiometer(SMMR)and other sensors of microwave satellite,the freeze-thaw cycle data of permafrost in the Qinghai-Xizang Plateau in the past 40 years from 1981 to 2020 was obtained.The changes of soil freeze-thaw conditions in different seasons of 2020 and in the same season of 1990,2000,2010 and 2020 were compared,and the annual variation trend of soil freeze-thaw area in the four years was analyzed.Further,the linear regression analysis was carried out on the duration of soil freezing/thawing/transition and the interannual variation trend under different area conditions from 1981 to 2020.The results show that the freeze-thaw changes in different years are similar.In winter,it is mainly frozen for about 110 days.Spring and autumn are transitional periods,lasting for 170 days.In summer,it is mainly thawed for about 80 days.From 1981 to 2020,the freezing period and the average freezing area of the Qinghai-Xizang Plateau decreased at a rate of 0.22 days and 1986 km^(2) per year,respectively,while the thawing period and the average thawing area increased at a rate of 0.07 days and 3187 km^(2) per year,respectively.The research results provide important theoretical support for the ecological environment and permafrost protection of the Qinghai-Xizang Plateau.展开更多
Global framework for nature management requires identifying areas of high priority for biodiversity conservation and restoration.The unique environments of Qinghai-Xizang Plateau(QXP) provide irreplaceable habitats fo...Global framework for nature management requires identifying areas of high priority for biodiversity conservation and restoration.The unique environments of Qinghai-Xizang Plateau(QXP) provide irreplaceable habitats for biodiversity which is prominent under future climate change.Despite the recent increase in research interest on conservation priorities,there is a lack of comprehensive and targeted protection strategies for pandemic species under climate change.Here,we compiled an exhaustive dataset with the variables of extinction risk and occurrence records of ectothermic lizards to investigate the conservation priorities in the QXP.We assessed the conservation status of the QXP lizards and identified the priority protected areas within the QXP under future climate scenarios using phylogenetic generalized least squares and ensemble species distribution models.Our analyses suggested nine lizard species to be prioritized for protection,with the most critical priority species being Dopasia gracilis,D.harti,and Phrynocephalus putjatai.Moreover,the priority protected areas covered~4.7%area of the QXP,mostly in the southern QXP and southeastern Hengduan Mountains.Protecting these regions would achieve a conservation effectiveness of≥95%for species richness,phylogenetic and functionaldiversity under climate change.Our findings provide realistic guidance for improving the conservation effectiveness of specific-lizard and-regions in the QXP under climate change.Our“bottom-up”approach could help the conservation efforts of other regions and species as an alternative to“top-down”global maps.展开更多
The Qinghai-Xizang Plateau serves as an extensive gene pool for plateau species and a crucial focal point for global biodiversity conservation.Being a climate-sensitive region,the impacts of climate change have led to...The Qinghai-Xizang Plateau serves as an extensive gene pool for plateau species and a crucial focal point for global biodiversity conservation.Being a climate-sensitive region,the impacts of climate change have led to habitat loss,population extinction,and ecological imbalances,posing formidable challenges to the sustained ef-fectiveness of existing protected areas.Despite substantial advancements in understanding species distribution,assessing habitat changes,and evaluating the efficiency of protected areas in recent decades,comprehensive evaluations encompassing all protected species are lacking,impeding conservation strategies.In this study,we gathered 137,856 observations,encompassing 2,605 species,and utilized the MaxEnt model to simulate changes in the current distribution patterns of endangered species and suitable habitats under future scenarios.We further proposed a climate smart approach to optimize the boundaries of protected areas in response to climate change.Key findings indicate that(1)the Qinghai-Xizang Plateau harbors 2,605 endangered species,constituting 34.04%of the total endangered species catalog in China;(2)current high-adaptation habitats of Qinghai-Xizang Plateau cover a mere 7%of the plateau,showing minimal alteration in protected efficiency under climate change sce-narios(0.50%increase);(3)incorporating the effects of climate change in adjusting protected area boundaries enhances their efficiency by an average of 20.52%.Our proposed methodology holds promise for safeguard-ing endangered species on the Qinghai-Xizang Plateau and offers significant implications for analogous regions worldwide.展开更多
Soil moisture is a key parameter in the exchange of energy and water between the land surface and the atmosphere.This parameter plays an important role in the dynamics of permafrost on the Qinghai-Xizang Plateau,China...Soil moisture is a key parameter in the exchange of energy and water between the land surface and the atmosphere.This parameter plays an important role in the dynamics of permafrost on the Qinghai-Xizang Plateau,China,as well as in the related ecological and hydrological processes.However,the region's complex terrain and extreme climatic conditions result in low-accuracy soil moisture estimations using traditional remote sensing techniques.Thus,this study considered parameters of the backscatter coefficient of Sentinel-1A ground range detected(GRD)data,the polarization decomposition parameters of Sentinel-1A single-look complex(SLC)data,the normalized difference vegetation index(NDVI)based on Sentinel-2B data,and the topographic factors based on digital elevation model(DEM)data.By combining these parameters with a machine learning model,we established a feature selection rule.A cumulative importance threshold was derived for feature variables,and those variables that failed to meet the threshold were eliminated based on variations in the coefficient of determination(R^(2))and the unbiased root mean square error(ubRMSE).The eight most influential variables were selected and combined with the CatBoost model for soil moisture inversion,and the SHapley Additive exPlanations(SHAP)method was used to analyze the importance of these variables.The results demonstrated that the optimized model significantly improved the accuracy of soil moisture inversion.Compared to the unfiltered model,the optimal feature combination led to a 0.09 increase in R^(2)and a 0.7%reduction in ubRMSE.Ultimately,the optimized model achieved a R²of 0.87 and an ubRMSE of 5.6%.Analysis revealed that soil particle size had significant impact on soil water retention capacity.The impact of vegetation on the estimated soil moisture on the Qinghai-Xizang Plateau was considerable,demonstrating a significant positive correlation.Moreover,the microtopographical features of hummocks interfered with soil moisture estimation,indicating that such terrain effects warrant increased attention in future studies within the permafrost regions.The developed method not only enhances the accuracy of soil moisture retrieval in the complex terrain of the Qinghai-Xizang Plateau,but also exhibits high computational efficiency(with a relative time reduction of 18.5%),striking an excellent balance between accuracy and efficiency.This approach provides a robust framework for efficient soil moisture monitoring in remote areas with limited ground data,offering critical insights for ecological conservation,water resource management,and climate change adaptation on the Qinghai-Xizang Plateau.展开更多
Maintaining community stability has profound positive impacts on the ecological functions and sustainable utilization of grassland ecosystems.Numerous studies have explored how community stability responds to climate ...Maintaining community stability has profound positive impacts on the ecological functions and sustainable utilization of grassland ecosystems.Numerous studies have explored how community stability responds to climate change and its relationship with plant species diversity.Nevertheless,the impact and underlying mechanisms of belowground ecosystem multifunctionality(BGEMF)on community stability along a precipitation gradient in alpine grasslands remain poorly understood.To address this knowledge gap,we conducted field surveys from 2015 to 2020,measuring plant species diversity,annual net primary productivity(ANPP),and soil physicochemical properties across 79 sites in alpine grassland ecosystems on the Qinghai-Xizang Plateau.Our findings highlight both plant species diversity(standardized total effect:32%)and BGEMF(standardized total effect:75%)had an indirect effect on stability viaregulating mean ANPP within alpine grasslands.Furthermore,mean annual precipitation substantially impacted both plant species diversity and BGEMF,subsequently affecting community stability.However,temperature had a strong negative regulatory effect on species diversity,the mean and variability of ANPP.Thus,we emphasized the pivotal role of plant species diversity and BGEMF in shaping community stability,and stated the imperative need for species conservation and BGEMF improvement to sustain alpine ecosystems in the face of ongoing climate change.展开更多
The Qinghai-Xizang Plateau(QXP)serves as a vital ecological security barrier in China and the broader Asian region.The delineation of urban growth boundaries(UGBs)in this region with consideration of socioeconomic dev...The Qinghai-Xizang Plateau(QXP)serves as a vital ecological security barrier in China and the broader Asian region.The delineation of urban growth boundaries(UGBs)in this region with consideration of socioeconomic development and ecological protection is urgently needed,but there is a lack of such research.The objective of this study is to delineate the UGBs on the QXP during 2020-2100 to simultaneously meet the needs of socioeconomic development and ecosystem services(ESs)protection.To achieve this purpose,under a scenario matrix integrating shared socioeconomic pathways(SSPs)and ESs protection,the urban expansion on the QXP during 2020-2100 was simulated by coupling the ESs assessment models and the zoned Land Use Scenario Dynamics-urban(LUSDurban)model.Finally,we compared the spatial patterns of the UGBs and the conservation effectiveness of ESs under different scenarios.The extent of UGBs on the QXP is projected to reach 2,045.60-2,231.10 km^(2),which is 62.23%-76.95%greater than the urban land area(1,260.90 km^(2))in 2020.Protecting the ESs can reduce the loss of the average natural habitat quality,food production,and carbon sequestration by 33.29%-34.27%,8.61%-18.23%,and 36.56%-40.34%,respectively.Protecting food production and carbon sequestration in Qinghai Province are more effective,but in the Xizang Autonomous Region,protecting ESs has a considerable trade-off effect.The UGBs delineated in this study can offer a reference for future urban planning on the QXP.展开更多
Due to irrational human activities and extreme climate,the Qinghai-Xizang Plateau,China,faces a serious threat of desertification.Desertification has a detrimental effect on the ecological environment and socioeconomi...Due to irrational human activities and extreme climate,the Qinghai-Xizang Plateau,China,faces a serious threat of desertification.Desertification has a detrimental effect on the ecological environment and socioeconomic development.In this study,the desertification sensitivity index(DSI)model was established by integrating the spatial distance model and environmentally sensitive area index evaluation method,and then the model was used to quantitatively analyze the spatial and temporal characteristics of desertification sensitivity of the Qinghai-Xizang Plateau from 1990 to 2020.The results revealed that:(1)a general increasing tendency from southeast to northwest was identified in the spatial distribution of desertification sensitivity.The low-sensitivity areas were mostly concentrated in the Hengduan and Nyaingqêntanglha mountains and surrounding forest and meadow areas.The high-sensitivity areas were located mainly in the Kunlun and Altun mountains and surrounding decertified areas.The center of gravity of all types of desertification-sensitive areas moved to the northwest,and the desertification sensitivity showed a decreasing trend as a whole;(2)the area of highly sensitive desertification areas decreased by 8.37%,with extreme sensitivity being the largest change among the sensitivity types.The desertification sensitivity transfer was characterized by a greater shift to lower sensitivity levels(24.56%)than to higher levels(2.03%),which demonstrated a declining trend;(3)since 1990,the change in desertification sensitivity has been dominated by the stabilizing type Ⅰ(29.30%),with the area of continuously increasing desertification sensitivity accounting for only 1.10%,indicating that the management of desertification has achieved positive results in recent years;and(4)natural factors have had a more significant impact on desertification sensitivity on the Xizang Plateau,whereas socioeconomic factors affected only localized areas.The main factors influencing desertification sensitivity were vegetation drought tolerance and aridity index.Studying spatiotemporal variations in desertification sensitivity and its influencing factors can provide a scientific foundation for developing strategies to control desertification on the Qinghai-Xizang Plateau.Dividing different desertification-sensitive areas on the basis of these patterns of change can facilitate the formulation of more targeted management and protection measures,contributing to ecological construction and sustainable economic development in the area.展开更多
Permafrost,a critical component of Earth’s climate system,is increasingly subject to abrupt thaw events,which jeopardize infrastructure,reshape landforms,alter hydrological regimes,and disrupt ecosystems,thereby posi...Permafrost,a critical component of Earth’s climate system,is increasingly subject to abrupt thaw events,which jeopardize infrastructure,reshape landforms,alter hydrological regimes,and disrupt ecosystems,thereby posing substantial threats to global sustainability.However,the underlying mechanisms that trigger these abrupt transitions remain incompletely understood.Here,we present decade-long in-situ observations from HRQ1,a marginal permafrost site in the Headwater Area of the Yellow River,northeastern Qinghai-Xizang Plateau.These data reveal the formation and growth of a talik,indicative of a permafrost tipping point.Absent before 2017,the talik subsequently formed and progressively deepened,extending to the maximum observation depth of 300 cm by 2024.The transition from perennially frozen to thawed conditions was accompanied by a substantial increase in mean annual soil temperature(MAST)throughout the entire soil profile.From 2015 to 2023,MAST in the upper 200 cm rose from sub-zero(−0.30 to−0.49℃)to consistently above 0℃(0.07 to 1.08℃).Concurrently,maximum daily soil temperatures in deeper layers(200–300 cm)became positive,indicating thaw propagation into the relict permafrost.This warming coincided with a marked increase in unfrozen soil moisture,particularly within the expanding talik.The rapid,non-linear deepening of the talik,far exceeding rates attributable to conductive heat transfer alone,was driven by a strong convective mechanism(Rayleigh-Darcy instability).This advective process was triggered when the soil profile became fully saturated,a condition resulting from the convergence of intensified rainfall and enhanced water retention linked to decadal vegetation greening.Intriguingly,despite the accelerated subsurface warming,the annual amplitude of ground surface temperature decreased from 29.0±2.8℃ to 24.5±3.6℃ following talik formation,likely due to the buffering effect of increased vegetation cover,which modified the surface energy balance.Our results demonstrate that climatic warming and wetting can initiate a cascade of internal feedbacks,propelling marginal permafrost beyond an abrupt tipping point.These findings emphasize the acute vulnerability of marginal permafrost and highlight the urgent necessity for sustained monitoring to assess ecosystem stability and quantify associated greenhouse gas emissions.展开更多
Various velocity models have been built for Southeast Qinghai-Xizang Plateau with the purpose of revealing the internal dynamics and estimating local seismic hazards.In this study,we use a 3-D full-waveform modeling p...Various velocity models have been built for Southeast Qinghai-Xizang Plateau with the purpose of revealing the internal dynamics and estimating local seismic hazards.In this study,we use a 3-D full-waveform modeling package to systematically validate three published continental-scale velocity models,that is,Shen2016,FWEA18,and USTClitho1.0,leveraging the ample datasets in Southeast Qinghai-Xizang Plateau region.Travel time residuals and waveform similarities are measured between observed empirical Green’s functions and synthetic waveforms.The results show that the Shen2016 model,derived from traditional surface wave tomography,performs best in fitting Rayleigh waves in the Southeast Qinghai-Xizang Plateau,followed by FWEA18,built from full-waveform inversion of long-period body and surface waves.The USTClitho1.0 model,although inverted from body wave datasets,is comparable with FWEA18 in fitting Rayleigh waves.The results also show that all the models are faster than the ground-truth model and show relatively large travel-time residuals and poor waveform similarities at shorter period bands,possibly caused by small-scale structural heterogeneities in the shallower crust.We further invert the time residuals for spatial velocity residuals and reveal that all three models underestimate the amplitudes of high-and low-velocity anomalies.The underestimated amplitude is up to 4%,which is non-negligible considering that the overall amplitude of anomalies is only 5%−10%in the crust.These results suggest that datasets and the inversion method are both essential to building accurate models and further refinements of these models are necessary.展开更多
This paper focuses on the Qinghai-Xizang Plateau.It systematically reviews its seismic activity characteristics and extensive environmental effects under extreme climatic conditions in dry and cold seasons.Firstly,thr...This paper focuses on the Qinghai-Xizang Plateau.It systematically reviews its seismic activity characteristics and extensive environmental effects under extreme climatic conditions in dry and cold seasons.Firstly,through detailed data analysis and literature review,it is revealed how the seasonal significant rainfall and temperature changes in the plateau establish potential links with key parameters such as the frequency and intensity of seismic activity.This process deeply analyzes how natural conditions such as extreme rainfall and temperature changes directly or indirectly affect the mechanism of earthquake preparation and triggering,which may promote or inhibit the occurrence of seismic activity.The close relationship between cold and dry seasons and seismic activity is emphasized,and the unique influence of these special climatic conditions on seismic activity patterns is discussed.In addition,the regional distribution characteristics of seismic activity in the plateau area are also analyzed,including key data such as annual occurrence number and magnitude distribution,which provides strong data support for formulating regional earthquake disaster response strategies.In addition,the characteristics of various secondary disasters that may be caused by earthquakes,such as landslides,debris flows,barrier lakes,etc.,are analyzed,which deepens the understanding of the complexity of the earthquake disaster chain.The aim is to provide a scientific basis for future earthquake disaster prevention and control work and to promote the improvement of earthquake science research and disaster management levels in the Qingzang Plateau and even the world.展开更多
The net primary productivity(NPP) is an important indicator for assessing the carbon sequestration capacities of different ecosystems and plays a crucial role in the global biosphere carbon cycle. However, in the cont...The net primary productivity(NPP) is an important indicator for assessing the carbon sequestration capacities of different ecosystems and plays a crucial role in the global biosphere carbon cycle. However, in the context of the increasing frequency, intensity, and duration of global extreme climate events, the impacts of extreme climate and vegetation phenology on NPP are still unclear, especially on the Qinghai-Xizang Plateau(QXP), China. In this study, we used a new data fusion method based on the MOD13A2 normalized difference vegetation index(NDVI) and the Global Inventory Modeling and Mapping Studies(GIMMS) NDVI_(3g) datasets to obtain a NDVI dataset(1982–2020) on the QXP. Then, we developed a NPP dataset across the QXP using the Carnegie-Ames-Stanford Approach(CASA) model and validated its applicability based on gauged NPP data. Subsequently, we calculated 18 extreme climate indices based on the CN05.1 dataset, and extracted the length of vegetation growing season using the threshold method and double logistic model based on the annual NDVI time series. Finally, we explored the spatiotemporal patterns of NPP on the QXP and the impact mechanisms of extreme climate and the length of vegetation growing season on NPP. The results indicated that the estimated NPP exhibited good applicability. Specifically, the correlation coefficient, relative bias, mean error, and root mean square error between the estimated NPP and gauged NPP were 0.76, 0.17, 52.89 g C/(m^(2)·a), and 217.52 g C/(m^(2)·a), respectively. The NPP of alpine meadow, alpine steppe, forest, and main ecosystem on the QXP mainly exhibited an increasing trend during 1982–2020, with rates of 0.35, 0.38, 1.40, and 0.48 g C/(m^(2)·a), respectively. Spatially, the NPP gradually decreased from southeast to northwest across the QXP. Extreme climate had greater impact on NPP than the length of vegetation growing season on the QXP. Specifically, the increase in extremely-wet-day precipitation(R99p), simple daily intensity index(SDII), and hottest day(TXx) increased the NPP in different ecosystems across the QXP, while the increases in the cold spell duration index(CSDI) and warm spell duration index(WSDI) decreased the NPP in these ecosystems. The results of this study provide a scientific basis for relevant departments to formulate future policies addressing the impact of extreme climate on vegetation in different ecosystems on the QXP.展开更多
Understanding how species diverge and adapt is fundamental to unraveling biodiversity.While environmental impacts on species evolution are well-documented,the roles of intrinsic life-history traits remain underexplore...Understanding how species diverge and adapt is fundamental to unraveling biodiversity.While environmental impacts on species evolution are well-documented,the roles of intrinsic life-history traits remain underexplored.The Qinghai-Xizang Plateau,with its harsh conditions and unique biodiversity,offers a natural laboratory for such investigations.Here,we examine two sympatric small mammals—the solitary,low-dispersal plateau zokor(Eospalax baileyi)and the social,high-dispersal plateau pika(Ochotona curzoniae)—to elucidate how life-history traits shape population structures and adaptive strategies.Through whole-genome sequencing and cardiac-blood phenotype analyses,we reveal striking differences in their evolutionary trajectories.Despite enduring similar environmental pressures,plateau zokor populations exhibit pronounced genetic subdivisions,high inbreeding,and distinct local adaptations.In contrast,plateau pika populations display genetic panmixia,widespread diversity,and adaptive uniformity.Demographic inference highlights that plateau zokors experienced severe population bottlenecks and restricted gene flow during glacial periods,underscoring the impact of dispersal capacity on evolutionary outcomes.Our findings demonstrate that intrinsic biological traits,particularly dispersal ability,fundamentally influence genetic architecture,population connectivity,and local adaptation.This study not only provides empirical evidence of how life-history traits shape evolutionary dynamics but also offers a framework for integrating intrinsic and extrinsic factors in understanding biodiversity formation.展开更多
Black tents,also known as black yak-wool tents due to their construction from yak wool,serve as the traditional accommodation for ethnic Tibetan nomads.From ancient times till now,these tents have long captured the no...Black tents,also known as black yak-wool tents due to their construction from yak wool,serve as the traditional accommodation for ethnic Tibetan nomads.From ancient times till now,these tents have long captured the nomadic life of herdsmen living on the Qinghai-Xizang Plateau.展开更多
Interannual and decadal variations of winter snow cover over the Qinghai-Xizang Plateau (QXP) are analyzed by using monthly mean snow depth data set of 60 stations over QXP for the period of 1958 through 1992. It is f...Interannual and decadal variations of winter snow cover over the Qinghai-Xizang Plateau (QXP) are analyzed by using monthly mean snow depth data set of 60 stations over QXP for the period of 1958 through 1992. It is found that the winter snow cover over QXP bears a pronounced quasi-biennial oscillation, and it underwent an obvious decadal transition from a poor snow cover period to a rich snow cover period in the late 1970’s during the last 40 years. It is shown that the summer rainfall in the eastern China is closely associated with the winter snow cov-er over QXP not only in the interannual variation but also in the decadal variation. A clear relationship ex-ists in the quasi-biennial oscillation between the summer rainfall in the northern part of North China and the southern China and the winter snow cover over QXP. Furthermore, the summer rainfall in the four cli-mate divisions of Qinling-Daba Mountains, the Yangtze-Huaihe River Plain, the upper and lower reaches of the Yangtze River showed a remarkable transition from drought period to rainy period in the end of 1970’s, in good correspondence with the decadal transition of the winter snow cover over QXP. Key words Snow cover over Qinghai-Xizang Plateau - Summer monsoon rainfall in China - Interannual and decadal variations This study was supported by the National Key Programme for Developing Basic Sciences (G 1998040900 Part I).展开更多
In recent twenty years, much numerical simulation work has been done on the evolution of Qinghai-Xizang (Tibetan) plateau. In this paper some principal numerical models and results are reviewed and analyzed. The earli...In recent twenty years, much numerical simulation work has been done on the evolution of Qinghai-Xizang (Tibetan) plateau. In this paper some principal numerical models and results are reviewed and analyzed. The earlier plane stress or plane strain model has much discrepancy with the actual deformation of Qinghai-Xizang plateau, such as the thickening of Tibetan crust and the lateral extrusion of Tibet along strike-slip faults. The thin viscous sheet model and the thin-plate model may simulate the change of the crustal thickness and the deformation pro-duced by gravitational force. It is suitable for studying the large-scale and long-time deformation. The influence of faults on the deformation of Tibetan plateau should be further studied.展开更多
Using radiation data from the Automatic Weather Stations (AWSs) for thermal balance obser-vations, which were set up at Lhasa, Nagqu, Xigaze and Nyingchi by the Sino-Japanese Asian Monsoon Mechanism Co-operative Proje...Using radiation data from the Automatic Weather Stations (AWSs) for thermal balance obser-vations, which were set up at Lhasa, Nagqu, Xigaze and Nyingchi by the Sino-Japanese Asian Monsoon Mechanism Co-operative Project in 1993–1996, and 1985–1989 Earth Radiation Balance Experiment (ERBE) measurements of Langley Research Center/NASA of US, and 1961–1996 monthly mean data from 148 surface stations over the Qinghai-Xizang Plateau (QXP) and its neighborhood, study is performed on empirical calculation methods of surface albedo, surface total radiation, planetary albedo and outgoing longwave radiation with the climatic features of radiation balance at the surface and the atmospheric top examined. Evidences suggest that the empirical formulae for surface albedo, planetary albedo, surface to-tal radiation and outgoing longwave radiation from the atmospheric top are capable of describing their seasonal and interannual variations over the QXP. The surface albedo is marked by noticeable seasonal variation and yearly mean of 0.22 with the maximum of 0.29 in January and minimum of 0.17 in July and August; in winter the albedo has great horizontal difference, bigger in the moun-tains than in the river valleys, and small in summer. The planetary albedo shows a smaller range of its annual variation with the yearly mean of 0.37, the maximum (minimum) occurring in February and March (autumn). In winter its high-value regions are mainly at Gar (Shiquanhe) in the western QXP and from the southwestern Qinghai to the northeastern Tibet and the low-value area at the northern slope of the central Himalayas; in summer, however, the albedo distribution displays clear-ly a progressive decrease from southeast to northwest. As for the surface total radiation, its values and annual varying range are smaller in the east than in the southwest. Its high-value center is at the southern slope of the Himalayas in winter and makes a conspicuous westward migration in spr-ing, remaining there for a long time, and it begins to retreat eastward in autumn. Monthly mean values of the surface net radiation are all positive and larger in summer than in winter. The net ra-diation is significantly intensified under the combined effect of surface total radiation and surface albedo from spring to early summer, resulting in the strongest sector in the mid plateau with its center staying nearly motionless from March to September, and is reduced in autumn dominantly by surface effective radiation. The earth-atmosphere system loses heat outward from October to next February and gains in other months. On an average, the plateau gains heat of 15 W m-2 on an annual basis. Key words The Qinghai-Xizang Plateau - Albedo - Radiation balance - Climatic feature (1)This work was supported under the auspices of the National (G1998040800) and CAS’s Key Project for Basic Research on Tibetan Plateau (KZ951-A1-204; KZ95T-06).展开更多
基金funded by the National Natural Science Foundation of China(No.42274066),the Second Qinghai-Xizang Plateau Scientific Expedition and Research Program(STEP)(No.2019Q ZKK0701).
文摘The Kumkol Basin,situated in the northern margin of the Qinghai-Xizang Plateau,provides a unique window into understanding the dynamic mechanisms driving the plateau’s northern expansion.However,its formation and tectonic evolution remain poorly understood due to limited geophysical data in this region.In this study,we computed cross-correlations for the TT components of station-pairs with high signal-to-noise ratios to extract Love wave waveforms and further performed Lovewave ambient noise tomography to image the upper crustal shear-wave velocity structure of the Kumkol basin down to 10 km depth.Our seismic velocity model reveals that the Kumkol Basin has a sedimentary thickness exceeding 8 km,with its center located near the Arka Mountain on the southern side.This suggests that the basin was likely formed as a foreland basin in response to the uplift of the Qiman Tagh Mountain to the north.Additionally,integrated with seismic reflection data,our seismic velocity model images a detachment fault at the basin basement depth.We inferred that the Kumkol Anticlinorium at the basin’s center have been produced by multiple thrust faults converging into this detachment fault at 8–10 km depth following the Early to Middle Miocene uplift of the Qiman Tagh Mountain.This structural configuration indicates pulsed basinward deformation since the late Miocene,likely reflecting a tectonic regime shift from extrusion to distributed shortening in the northern Qinghai-Xizang Plateau.Our findings provide a high-resolution velocity model of the Kumkol Basin,offering critical insights into its structural evolution and supporting future resource exploration in this underexplored region.
基金funded by the National Natural Science Foundation of China(42101276)the Major Project of Key Research Bases for Humanities and Social Sciences Funded by the Ministry of Education of China(22JJD790015)the Science and Technology Project of Gansu Province,China(20JR5RA529).
文摘The Qinghai-Xizang Plateau(QXP)serves as a crucial ecological barrier in China and Asia,exerting profound influences on global climate and biodiversity conservation.Gannan Tibetan Autonomous Prefecture(hereinafter referred as Gannan Prefecture),located on the northeastern edge of the QXP,represents a fragile alpine ecosystem in which land use change significantly impacts ecosystem services(ESs).This study established a comprehensive framework,utilizing the Patch-generating Land-Use Simulation(PLUS)model coupled with the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model to predict land use patterns under the natural development scenario,cultivated land protection scenario,and ecological protection scenario for Gannan Prefecture by 2030 and evaluated four critical ESs:habitat quality(HQ),water yield(WY),soil retention(SR),and carbon storage(CS).The primary aim is to elucidate the impacts of dynamic land use change on ESs.The results revealed that,from 2000 to 2020,HQ exhibited minimal variation,whereas CS experienced a slight decline.Conversely,WY and SR showed significant improvements.Under the natural development scenario,construction land was projected to increase by 4247.74 hm^(2),primarily at the expense of forest land.The cultivated land protection scenario anticipated an increase in farmland by 2634.36 hm^(2),which was crucial for maintaining food security.The ecological protection scenario predicted a notable expansion of forest land,accompanied by a restrained development rate of construction land.The ecological protection scenario also showed an increase in the ecosystem service index(ESI),encompassing 26.07%of the region.Forest land and grassland emerged as the primary contributors to ESs,while construction land substantially impacted WY.Water bodies exhibited minimal contribution to ESs.This study enhanced the understanding of land use change impacts on ESs in fragile and high-altitude ecosystems,offering essential theoretical frameworks and practical direction for forthcoming ecological policy and regional planning endeavors.
基金supported by the Qinghai Science and Technology Department Project(2025-QY-225)the National Natural Science Foundation of China(42267024)the Second Comprehensive Scientific Investigation and Research Project of the Qinghai-Xizang Plateau(2019QZKK0905).
文摘The Qinghai-Xizang Plateau of China faces challenges like thaw slumping,threatening slope stability and infrastructure.Understanding the mechanical properties of the roots of the dominant herbaceous plant species in the alpine meadow layer of the permafrost regions on the Qinghai-Xizang Plateau is essential for evaluating their role in enhancing soil shear strength and mitigating slope deformation in these fragile environments.In this study,the roots of four dominant herbaceous plant species—Kobresia pygmaea,Kobresia humilis,Carex moorcroftii,and Leontopodium pusillum—that are widely distributed in the permafrost regions of the Qinghai-Xizang Plateau were explored to determine their mechanical properties and effects in enhancing soil shear strength.Through indoor single root tensile and root group tensile tests,we determined the root diameter,tensile force,tensile strength,tensile ratio,and strength frequency distributions.We also evaluated their contributions to inhibiting slope deformation and failure during the formation and development of thermal thaw slumps in the alpine meadow.The results showed that the distribution of the root diameter of the dominant plant species is mostly normal,while the tensile strength tends to be logarithmically normally distributed.The relationship between the root diameter and root tensile strength conforms to a power function.The theoretical tensile strength of the root group was calculated using the Wu-Waldron Model(WWM)and the Fiber Bundle Model(FBM)under the assumption that the cumulative single tensile strength of the root bundle is identical to the tensile strength of the root group in the WWM.The FBM considers three fracture modes:FBM-D(the tensile force on each single root is proportional to its diameter relative to the total sum of all the root diameters),FBM-S(the cross-sectional stress in the root bundle is uniform),and FBM-N(each tensile strength test of individual roots experiences an equal load).It was found that the model-calculated tensile strength of the root group was 162.60%higher than the test value.The model-derived tensile force of the root group from the FBM-D,FBM-S,and FBM-N was 73.10%,28.91%,and 13.47%higher than the test values,respectively.The additional cohesion of the soil provided by the roots was calculated to be 25.90-45.06 kPa using the modified WWM,67.05-38.15 kPa using the FBM-S,and 57.24-32.74 kPa using the FBM-N.These results not only provide a theoretical basis for further quantitative evaluation of the mechanical effects of the root systems of herbaceous plant species in reinforcing the surface soil but also have practical significance for the effective prevention and control of thermal thaw slumping disasters in the permafrost regions containing native alpine meadows on the Qinghai-Xizang Plateau using flexible plant protection measures.
基金supported by the State Key Program of National Natural Science of China(Grant No.42330410)National Natural Science Foundation of China(Grant No.42101128)。
文摘Antibiotic resistance genes(ARGs)are increasingly recognized as a global public health threat,with glaciers acting as reservoirs for ARGs transported via atmospheric pathways.Warming climate accelerates glacier melting,releasing ARGs into downstream environments,posing ecological health and sustainable aquatic ecosystem development challenges.However,the distribution profiles of ARGs and their risks in glaciers from the polar region remain unclear.This study used 294 metagenomic sequences to investigate the distribution and risks of ARGs in glaciers across the Qinghai-Xizang Plateau,Antarctica,and the Arctic regions and compared them with adjacent and anthropogenically impacted environments.Among the three glacier regions studied,the Qinghai-Xizang Plateau exhibited the highest abundance of ARGs,whereas Antarctica displayed the lowest.ARG abundance in adjacent environments was comparable to that in the glaciers of the Qinghai-Xizang Plateau,but in the anthropogenically impacted environment,it was significantly higher than in glaciers.A shared resistome was identified in glaciers,dominated by bacitracin,multidrug,and macrolide-lincosamide-streptogramin(MLS)resistance genes.The bacA gene,which is related to bacitracin resistance,was the most common subtype,indicating that it is naturally present in microbial communities of glaciers.Risk assessments showed that 74.1%–78.9%of ARGs were low-risk in the Qinghai-Xizang Plateau and polar glaciers,indicating minimal human influence.However,7.3%–8.0%were classified as high-risk,posing potential threats through horizontal gene transfer(HGT)and the spread of multidrug-resistant pathogens.These findings highlight the need to monitor ARGs in glacier environments,as climate change accelerates glacier melting and subsequent release of ARGs into downstream ecosystems.
基金National Natural Science foundation of China(No.42271432)Foundation of Shanxi Vocational University of Engineering Science and Technology(No.KJ 202426).
文摘Strong sensitivity of satellite microwave remote sensing to the change of surface dielectric properties,as well as the insensitivity to air pollution and solar illumination effects,makes it very suitable for monitoring freeze-thaw conditions.The freeze-thaw cycle changes in the Qinghai-Xizang Plateau have an important impact on the ecological environment and infrastructure.Based on the Scanning Multi-channel Microwave Radiometer(SMMR)and other sensors of microwave satellite,the freeze-thaw cycle data of permafrost in the Qinghai-Xizang Plateau in the past 40 years from 1981 to 2020 was obtained.The changes of soil freeze-thaw conditions in different seasons of 2020 and in the same season of 1990,2000,2010 and 2020 were compared,and the annual variation trend of soil freeze-thaw area in the four years was analyzed.Further,the linear regression analysis was carried out on the duration of soil freezing/thawing/transition and the interannual variation trend under different area conditions from 1981 to 2020.The results show that the freeze-thaw changes in different years are similar.In winter,it is mainly frozen for about 110 days.Spring and autumn are transitional periods,lasting for 170 days.In summer,it is mainly thawed for about 80 days.From 1981 to 2020,the freezing period and the average freezing area of the Qinghai-Xizang Plateau decreased at a rate of 0.22 days and 1986 km^(2) per year,respectively,while the thawing period and the average thawing area increased at a rate of 0.07 days and 3187 km^(2) per year,respectively.The research results provide important theoretical support for the ecological environment and permafrost protection of the Qinghai-Xizang Plateau.
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20050201)the National Natural Science Foundation of China (31861143023,31872250 and 31872252)。
文摘Global framework for nature management requires identifying areas of high priority for biodiversity conservation and restoration.The unique environments of Qinghai-Xizang Plateau(QXP) provide irreplaceable habitats for biodiversity which is prominent under future climate change.Despite the recent increase in research interest on conservation priorities,there is a lack of comprehensive and targeted protection strategies for pandemic species under climate change.Here,we compiled an exhaustive dataset with the variables of extinction risk and occurrence records of ectothermic lizards to investigate the conservation priorities in the QXP.We assessed the conservation status of the QXP lizards and identified the priority protected areas within the QXP under future climate scenarios using phylogenetic generalized least squares and ensemble species distribution models.Our analyses suggested nine lizard species to be prioritized for protection,with the most critical priority species being Dopasia gracilis,D.harti,and Phrynocephalus putjatai.Moreover,the priority protected areas covered~4.7%area of the QXP,mostly in the southern QXP and southeastern Hengduan Mountains.Protecting these regions would achieve a conservation effectiveness of≥95%for species richness,phylogenetic and functionaldiversity under climate change.Our findings provide realistic guidance for improving the conservation effectiveness of specific-lizard and-regions in the QXP under climate change.Our“bottom-up”approach could help the conservation efforts of other regions and species as an alternative to“top-down”global maps.
基金funded by the National Natural Science Foun-dation of China(Grant No.41925005)the National Key R&D Pro-gram of China(Grant No.2024YFF1306103)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0307).
文摘The Qinghai-Xizang Plateau serves as an extensive gene pool for plateau species and a crucial focal point for global biodiversity conservation.Being a climate-sensitive region,the impacts of climate change have led to habitat loss,population extinction,and ecological imbalances,posing formidable challenges to the sustained ef-fectiveness of existing protected areas.Despite substantial advancements in understanding species distribution,assessing habitat changes,and evaluating the efficiency of protected areas in recent decades,comprehensive evaluations encompassing all protected species are lacking,impeding conservation strategies.In this study,we gathered 137,856 observations,encompassing 2,605 species,and utilized the MaxEnt model to simulate changes in the current distribution patterns of endangered species and suitable habitats under future scenarios.We further proposed a climate smart approach to optimize the boundaries of protected areas in response to climate change.Key findings indicate that(1)the Qinghai-Xizang Plateau harbors 2,605 endangered species,constituting 34.04%of the total endangered species catalog in China;(2)current high-adaptation habitats of Qinghai-Xizang Plateau cover a mere 7%of the plateau,showing minimal alteration in protected efficiency under climate change sce-narios(0.50%increase);(3)incorporating the effects of climate change in adjusting protected area boundaries enhances their efficiency by an average of 20.52%.Our proposed methodology holds promise for safeguard-ing endangered species on the Qinghai-Xizang Plateau and offers significant implications for analogous regions worldwide.
基金supported by the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(13230550)the Coal Industry Engineering Research Center of Mining Area Environmental and Disaster Cooperative Monitoring,Anhui University of Science and Technology(KSXTJC202305)+1 种基金the State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology(SKLGED2023-5-1)the China Postdoctoral Science Foundation(2023M733604).
文摘Soil moisture is a key parameter in the exchange of energy and water between the land surface and the atmosphere.This parameter plays an important role in the dynamics of permafrost on the Qinghai-Xizang Plateau,China,as well as in the related ecological and hydrological processes.However,the region's complex terrain and extreme climatic conditions result in low-accuracy soil moisture estimations using traditional remote sensing techniques.Thus,this study considered parameters of the backscatter coefficient of Sentinel-1A ground range detected(GRD)data,the polarization decomposition parameters of Sentinel-1A single-look complex(SLC)data,the normalized difference vegetation index(NDVI)based on Sentinel-2B data,and the topographic factors based on digital elevation model(DEM)data.By combining these parameters with a machine learning model,we established a feature selection rule.A cumulative importance threshold was derived for feature variables,and those variables that failed to meet the threshold were eliminated based on variations in the coefficient of determination(R^(2))and the unbiased root mean square error(ubRMSE).The eight most influential variables were selected and combined with the CatBoost model for soil moisture inversion,and the SHapley Additive exPlanations(SHAP)method was used to analyze the importance of these variables.The results demonstrated that the optimized model significantly improved the accuracy of soil moisture inversion.Compared to the unfiltered model,the optimal feature combination led to a 0.09 increase in R^(2)and a 0.7%reduction in ubRMSE.Ultimately,the optimized model achieved a R²of 0.87 and an ubRMSE of 5.6%.Analysis revealed that soil particle size had significant impact on soil water retention capacity.The impact of vegetation on the estimated soil moisture on the Qinghai-Xizang Plateau was considerable,demonstrating a significant positive correlation.Moreover,the microtopographical features of hummocks interfered with soil moisture estimation,indicating that such terrain effects warrant increased attention in future studies within the permafrost regions.The developed method not only enhances the accuracy of soil moisture retrieval in the complex terrain of the Qinghai-Xizang Plateau,but also exhibits high computational efficiency(with a relative time reduction of 18.5%),striking an excellent balance between accuracy and efficiency.This approach provides a robust framework for efficient soil moisture monitoring in remote areas with limited ground data,offering critical insights for ecological conservation,water resource management,and climate change adaptation on the Qinghai-Xizang Plateau.
基金supported financially by the National Natural Science Foundation of China(Grant No.32271774).
文摘Maintaining community stability has profound positive impacts on the ecological functions and sustainable utilization of grassland ecosystems.Numerous studies have explored how community stability responds to climate change and its relationship with plant species diversity.Nevertheless,the impact and underlying mechanisms of belowground ecosystem multifunctionality(BGEMF)on community stability along a precipitation gradient in alpine grasslands remain poorly understood.To address this knowledge gap,we conducted field surveys from 2015 to 2020,measuring plant species diversity,annual net primary productivity(ANPP),and soil physicochemical properties across 79 sites in alpine grassland ecosystems on the Qinghai-Xizang Plateau.Our findings highlight both plant species diversity(standardized total effect:32%)and BGEMF(standardized total effect:75%)had an indirect effect on stability viaregulating mean ANPP within alpine grasslands.Furthermore,mean annual precipitation substantially impacted both plant species diversity and BGEMF,subsequently affecting community stability.However,temperature had a strong negative regulatory effect on species diversity,the mean and variability of ANPP.Thus,we emphasized the pivotal role of plant species diversity and BGEMF in shaping community stability,and stated the imperative need for species conservation and BGEMF improvement to sustain alpine ecosystems in the face of ongoing climate change.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0405)the Science and Technology Department of Qinghai Province(Grant No.2023-ZJ-929 M)supported by the project from State Key Laboratory of Earth Surface Processes and Hazards Risk Governance,China。
文摘The Qinghai-Xizang Plateau(QXP)serves as a vital ecological security barrier in China and the broader Asian region.The delineation of urban growth boundaries(UGBs)in this region with consideration of socioeconomic development and ecological protection is urgently needed,but there is a lack of such research.The objective of this study is to delineate the UGBs on the QXP during 2020-2100 to simultaneously meet the needs of socioeconomic development and ecosystem services(ESs)protection.To achieve this purpose,under a scenario matrix integrating shared socioeconomic pathways(SSPs)and ESs protection,the urban expansion on the QXP during 2020-2100 was simulated by coupling the ESs assessment models and the zoned Land Use Scenario Dynamics-urban(LUSDurban)model.Finally,we compared the spatial patterns of the UGBs and the conservation effectiveness of ESs under different scenarios.The extent of UGBs on the QXP is projected to reach 2,045.60-2,231.10 km^(2),which is 62.23%-76.95%greater than the urban land area(1,260.90 km^(2))in 2020.Protecting the ESs can reduce the loss of the average natural habitat quality,food production,and carbon sequestration by 33.29%-34.27%,8.61%-18.23%,and 36.56%-40.34%,respectively.Protecting food production and carbon sequestration in Qinghai Province are more effective,but in the Xizang Autonomous Region,protecting ESs has a considerable trade-off effect.The UGBs delineated in this study can offer a reference for future urban planning on the QXP.
基金funded by the National Natural Science Foundation of China(42371219)the Key Natural Science Foundation of Gansu Province(24JRRA135)the Oasis Scientific Research Achievements Breakthrough Action Plan Project of Northwest Normal University(NWNU-LZKX-202302).
文摘Due to irrational human activities and extreme climate,the Qinghai-Xizang Plateau,China,faces a serious threat of desertification.Desertification has a detrimental effect on the ecological environment and socioeconomic development.In this study,the desertification sensitivity index(DSI)model was established by integrating the spatial distance model and environmentally sensitive area index evaluation method,and then the model was used to quantitatively analyze the spatial and temporal characteristics of desertification sensitivity of the Qinghai-Xizang Plateau from 1990 to 2020.The results revealed that:(1)a general increasing tendency from southeast to northwest was identified in the spatial distribution of desertification sensitivity.The low-sensitivity areas were mostly concentrated in the Hengduan and Nyaingqêntanglha mountains and surrounding forest and meadow areas.The high-sensitivity areas were located mainly in the Kunlun and Altun mountains and surrounding decertified areas.The center of gravity of all types of desertification-sensitive areas moved to the northwest,and the desertification sensitivity showed a decreasing trend as a whole;(2)the area of highly sensitive desertification areas decreased by 8.37%,with extreme sensitivity being the largest change among the sensitivity types.The desertification sensitivity transfer was characterized by a greater shift to lower sensitivity levels(24.56%)than to higher levels(2.03%),which demonstrated a declining trend;(3)since 1990,the change in desertification sensitivity has been dominated by the stabilizing type Ⅰ(29.30%),with the area of continuously increasing desertification sensitivity accounting for only 1.10%,indicating that the management of desertification has achieved positive results in recent years;and(4)natural factors have had a more significant impact on desertification sensitivity on the Xizang Plateau,whereas socioeconomic factors affected only localized areas.The main factors influencing desertification sensitivity were vegetation drought tolerance and aridity index.Studying spatiotemporal variations in desertification sensitivity and its influencing factors can provide a scientific foundation for developing strategies to control desertification on the Qinghai-Xizang Plateau.Dividing different desertification-sensitive areas on the basis of these patterns of change can facilitate the formulation of more targeted management and protection measures,contributing to ecological construction and sustainable economic development in the area.
基金funded by the Science and Technology program of Gansu Province(Grant No.23ZDFA017)Longyuan Young Talents(D.Luo),Western Young Scholars Project of the Chinese Academy of Sciences(D.Luo)National Natural Science Foundation of China(U2243214).
文摘Permafrost,a critical component of Earth’s climate system,is increasingly subject to abrupt thaw events,which jeopardize infrastructure,reshape landforms,alter hydrological regimes,and disrupt ecosystems,thereby posing substantial threats to global sustainability.However,the underlying mechanisms that trigger these abrupt transitions remain incompletely understood.Here,we present decade-long in-situ observations from HRQ1,a marginal permafrost site in the Headwater Area of the Yellow River,northeastern Qinghai-Xizang Plateau.These data reveal the formation and growth of a talik,indicative of a permafrost tipping point.Absent before 2017,the talik subsequently formed and progressively deepened,extending to the maximum observation depth of 300 cm by 2024.The transition from perennially frozen to thawed conditions was accompanied by a substantial increase in mean annual soil temperature(MAST)throughout the entire soil profile.From 2015 to 2023,MAST in the upper 200 cm rose from sub-zero(−0.30 to−0.49℃)to consistently above 0℃(0.07 to 1.08℃).Concurrently,maximum daily soil temperatures in deeper layers(200–300 cm)became positive,indicating thaw propagation into the relict permafrost.This warming coincided with a marked increase in unfrozen soil moisture,particularly within the expanding talik.The rapid,non-linear deepening of the talik,far exceeding rates attributable to conductive heat transfer alone,was driven by a strong convective mechanism(Rayleigh-Darcy instability).This advective process was triggered when the soil profile became fully saturated,a condition resulting from the convergence of intensified rainfall and enhanced water retention linked to decadal vegetation greening.Intriguingly,despite the accelerated subsurface warming,the annual amplitude of ground surface temperature decreased from 29.0±2.8℃ to 24.5±3.6℃ following talik formation,likely due to the buffering effect of increased vegetation cover,which modified the surface energy balance.Our results demonstrate that climatic warming and wetting can initiate a cascade of internal feedbacks,propelling marginal permafrost beyond an abrupt tipping point.These findings emphasize the acute vulnerability of marginal permafrost and highlight the urgent necessity for sustained monitoring to assess ecosystem stability and quantify associated greenhouse gas emissions.
基金supported by the Special Fund of the Institute of Geophysics,China Earthquake Administration(Nos.DQJB23R28 and DQJB22K40)the National Natural Science Foundation of China(Nos.42304078,U1839210 and 42104043).
文摘Various velocity models have been built for Southeast Qinghai-Xizang Plateau with the purpose of revealing the internal dynamics and estimating local seismic hazards.In this study,we use a 3-D full-waveform modeling package to systematically validate three published continental-scale velocity models,that is,Shen2016,FWEA18,and USTClitho1.0,leveraging the ample datasets in Southeast Qinghai-Xizang Plateau region.Travel time residuals and waveform similarities are measured between observed empirical Green’s functions and synthetic waveforms.The results show that the Shen2016 model,derived from traditional surface wave tomography,performs best in fitting Rayleigh waves in the Southeast Qinghai-Xizang Plateau,followed by FWEA18,built from full-waveform inversion of long-period body and surface waves.The USTClitho1.0 model,although inverted from body wave datasets,is comparable with FWEA18 in fitting Rayleigh waves.The results also show that all the models are faster than the ground-truth model and show relatively large travel-time residuals and poor waveform similarities at shorter period bands,possibly caused by small-scale structural heterogeneities in the shallower crust.We further invert the time residuals for spatial velocity residuals and reveal that all three models underestimate the amplitudes of high-and low-velocity anomalies.The underestimated amplitude is up to 4%,which is non-negligible considering that the overall amplitude of anomalies is only 5%−10%in the crust.These results suggest that datasets and the inversion method are both essential to building accurate models and further refinements of these models are necessary.
基金supported by the National Natural Science Foundation of China (42461020)Gansu Province joint research fund project (24JRRA857,24JRRA847,24JRRA799).
文摘This paper focuses on the Qinghai-Xizang Plateau.It systematically reviews its seismic activity characteristics and extensive environmental effects under extreme climatic conditions in dry and cold seasons.Firstly,through detailed data analysis and literature review,it is revealed how the seasonal significant rainfall and temperature changes in the plateau establish potential links with key parameters such as the frequency and intensity of seismic activity.This process deeply analyzes how natural conditions such as extreme rainfall and temperature changes directly or indirectly affect the mechanism of earthquake preparation and triggering,which may promote or inhibit the occurrence of seismic activity.The close relationship between cold and dry seasons and seismic activity is emphasized,and the unique influence of these special climatic conditions on seismic activity patterns is discussed.In addition,the regional distribution characteristics of seismic activity in the plateau area are also analyzed,including key data such as annual occurrence number and magnitude distribution,which provides strong data support for formulating regional earthquake disaster response strategies.In addition,the characteristics of various secondary disasters that may be caused by earthquakes,such as landslides,debris flows,barrier lakes,etc.,are analyzed,which deepens the understanding of the complexity of the earthquake disaster chain.The aim is to provide a scientific basis for future earthquake disaster prevention and control work and to promote the improvement of earthquake science research and disaster management levels in the Qingzang Plateau and even the world.
基金supported by the National Natural Science Foundation of China (U2243227)。
文摘The net primary productivity(NPP) is an important indicator for assessing the carbon sequestration capacities of different ecosystems and plays a crucial role in the global biosphere carbon cycle. However, in the context of the increasing frequency, intensity, and duration of global extreme climate events, the impacts of extreme climate and vegetation phenology on NPP are still unclear, especially on the Qinghai-Xizang Plateau(QXP), China. In this study, we used a new data fusion method based on the MOD13A2 normalized difference vegetation index(NDVI) and the Global Inventory Modeling and Mapping Studies(GIMMS) NDVI_(3g) datasets to obtain a NDVI dataset(1982–2020) on the QXP. Then, we developed a NPP dataset across the QXP using the Carnegie-Ames-Stanford Approach(CASA) model and validated its applicability based on gauged NPP data. Subsequently, we calculated 18 extreme climate indices based on the CN05.1 dataset, and extracted the length of vegetation growing season using the threshold method and double logistic model based on the annual NDVI time series. Finally, we explored the spatiotemporal patterns of NPP on the QXP and the impact mechanisms of extreme climate and the length of vegetation growing season on NPP. The results indicated that the estimated NPP exhibited good applicability. Specifically, the correlation coefficient, relative bias, mean error, and root mean square error between the estimated NPP and gauged NPP were 0.76, 0.17, 52.89 g C/(m^(2)·a), and 217.52 g C/(m^(2)·a), respectively. The NPP of alpine meadow, alpine steppe, forest, and main ecosystem on the QXP mainly exhibited an increasing trend during 1982–2020, with rates of 0.35, 0.38, 1.40, and 0.48 g C/(m^(2)·a), respectively. Spatially, the NPP gradually decreased from southeast to northwest across the QXP. Extreme climate had greater impact on NPP than the length of vegetation growing season on the QXP. Specifically, the increase in extremely-wet-day precipitation(R99p), simple daily intensity index(SDII), and hottest day(TXx) increased the NPP in different ecosystems across the QXP, while the increases in the cold spell duration index(CSDI) and warm spell duration index(WSDI) decreased the NPP in these ecosystems. The results of this study provide a scientific basis for relevant departments to formulate future policies addressing the impact of extreme climate on vegetation in different ecosystems on the QXP.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK05010900 and 2019QZKK05010405)the National Natural Science Foundation of China(32100339 and 32200350)+3 种基金Yunnan Revitalization Talent Support Program Top team(202405AS350022)supported by the Youth Innovation Promotion Association,Chinese Academy of Sciencessupported by Yunnan Fundamental Research Projects(202201AU070208)supported by Yunnan Revitalization Talent Support Program Yunling Scholar Project(XML)。
文摘Understanding how species diverge and adapt is fundamental to unraveling biodiversity.While environmental impacts on species evolution are well-documented,the roles of intrinsic life-history traits remain underexplored.The Qinghai-Xizang Plateau,with its harsh conditions and unique biodiversity,offers a natural laboratory for such investigations.Here,we examine two sympatric small mammals—the solitary,low-dispersal plateau zokor(Eospalax baileyi)and the social,high-dispersal plateau pika(Ochotona curzoniae)—to elucidate how life-history traits shape population structures and adaptive strategies.Through whole-genome sequencing and cardiac-blood phenotype analyses,we reveal striking differences in their evolutionary trajectories.Despite enduring similar environmental pressures,plateau zokor populations exhibit pronounced genetic subdivisions,high inbreeding,and distinct local adaptations.In contrast,plateau pika populations display genetic panmixia,widespread diversity,and adaptive uniformity.Demographic inference highlights that plateau zokors experienced severe population bottlenecks and restricted gene flow during glacial periods,underscoring the impact of dispersal capacity on evolutionary outcomes.Our findings demonstrate that intrinsic biological traits,particularly dispersal ability,fundamentally influence genetic architecture,population connectivity,and local adaptation.This study not only provides empirical evidence of how life-history traits shape evolutionary dynamics but also offers a framework for integrating intrinsic and extrinsic factors in understanding biodiversity formation.
文摘Black tents,also known as black yak-wool tents due to their construction from yak wool,serve as the traditional accommodation for ethnic Tibetan nomads.From ancient times till now,these tents have long captured the nomadic life of herdsmen living on the Qinghai-Xizang Plateau.
文摘Interannual and decadal variations of winter snow cover over the Qinghai-Xizang Plateau (QXP) are analyzed by using monthly mean snow depth data set of 60 stations over QXP for the period of 1958 through 1992. It is found that the winter snow cover over QXP bears a pronounced quasi-biennial oscillation, and it underwent an obvious decadal transition from a poor snow cover period to a rich snow cover period in the late 1970’s during the last 40 years. It is shown that the summer rainfall in the eastern China is closely associated with the winter snow cov-er over QXP not only in the interannual variation but also in the decadal variation. A clear relationship ex-ists in the quasi-biennial oscillation between the summer rainfall in the northern part of North China and the southern China and the winter snow cover over QXP. Furthermore, the summer rainfall in the four cli-mate divisions of Qinling-Daba Mountains, the Yangtze-Huaihe River Plain, the upper and lower reaches of the Yangtze River showed a remarkable transition from drought period to rainy period in the end of 1970’s, in good correspondence with the decadal transition of the winter snow cover over QXP. Key words Snow cover over Qinghai-Xizang Plateau - Summer monsoon rainfall in China - Interannual and decadal variations This study was supported by the National Key Programme for Developing Basic Sciences (G 1998040900 Part I).
文摘In recent twenty years, much numerical simulation work has been done on the evolution of Qinghai-Xizang (Tibetan) plateau. In this paper some principal numerical models and results are reviewed and analyzed. The earlier plane stress or plane strain model has much discrepancy with the actual deformation of Qinghai-Xizang plateau, such as the thickening of Tibetan crust and the lateral extrusion of Tibet along strike-slip faults. The thin viscous sheet model and the thin-plate model may simulate the change of the crustal thickness and the deformation pro-duced by gravitational force. It is suitable for studying the large-scale and long-time deformation. The influence of faults on the deformation of Tibetan plateau should be further studied.
文摘Using radiation data from the Automatic Weather Stations (AWSs) for thermal balance obser-vations, which were set up at Lhasa, Nagqu, Xigaze and Nyingchi by the Sino-Japanese Asian Monsoon Mechanism Co-operative Project in 1993–1996, and 1985–1989 Earth Radiation Balance Experiment (ERBE) measurements of Langley Research Center/NASA of US, and 1961–1996 monthly mean data from 148 surface stations over the Qinghai-Xizang Plateau (QXP) and its neighborhood, study is performed on empirical calculation methods of surface albedo, surface total radiation, planetary albedo and outgoing longwave radiation with the climatic features of radiation balance at the surface and the atmospheric top examined. Evidences suggest that the empirical formulae for surface albedo, planetary albedo, surface to-tal radiation and outgoing longwave radiation from the atmospheric top are capable of describing their seasonal and interannual variations over the QXP. The surface albedo is marked by noticeable seasonal variation and yearly mean of 0.22 with the maximum of 0.29 in January and minimum of 0.17 in July and August; in winter the albedo has great horizontal difference, bigger in the moun-tains than in the river valleys, and small in summer. The planetary albedo shows a smaller range of its annual variation with the yearly mean of 0.37, the maximum (minimum) occurring in February and March (autumn). In winter its high-value regions are mainly at Gar (Shiquanhe) in the western QXP and from the southwestern Qinghai to the northeastern Tibet and the low-value area at the northern slope of the central Himalayas; in summer, however, the albedo distribution displays clear-ly a progressive decrease from southeast to northwest. As for the surface total radiation, its values and annual varying range are smaller in the east than in the southwest. Its high-value center is at the southern slope of the Himalayas in winter and makes a conspicuous westward migration in spr-ing, remaining there for a long time, and it begins to retreat eastward in autumn. Monthly mean values of the surface net radiation are all positive and larger in summer than in winter. The net ra-diation is significantly intensified under the combined effect of surface total radiation and surface albedo from spring to early summer, resulting in the strongest sector in the mid plateau with its center staying nearly motionless from March to September, and is reduced in autumn dominantly by surface effective radiation. The earth-atmosphere system loses heat outward from October to next February and gains in other months. On an average, the plateau gains heat of 15 W m-2 on an annual basis. Key words The Qinghai-Xizang Plateau - Albedo - Radiation balance - Climatic feature (1)This work was supported under the auspices of the National (G1998040800) and CAS’s Key Project for Basic Research on Tibetan Plateau (KZ951-A1-204; KZ95T-06).
