Elevation and Human Disturbance Interactively Influence the Patterns of Insect Diversity on the Southeastern Periphery of the Tibetan Plateau.

The maintenance of biodiversity and ecological balance heavily relies on the diversity of insects. In order to investigate the impacts of elevation and human disturbance, as well as their interactions on insect diversity, we conducted an intensive survey of insects in the Hengduan Mountain Range, which is situated on the southeastern periphery of the Tibetan Plateau in China. A total of 50 line transects were established in this study to investigate the impact of elevation and human disturbance on insect diversity and distribution patterns. Designed insect surveys were conducted at various elevations and levels of human disturbance, and statistical methods such as generalized linear modeling and redundancy analysis were employed for data analysis. The results of this study indicated a negative correlation between insect diversity and elevation. Additionally, moderate disturbance was found to have a positive impact on insect diversity to some extent. The explanatory power of the model for the distribution of insect diversity could be improved if elevation and human disturbance were included as an interaction effect into the model, and there were differences in the effects of human disturbances on insect diversity at different elevation levels. The highest insect diversity was observed under low disturbance conditions below elevation of ~2200 m, whereas above this threshold, insect diversity was the highest under moderate disturbance compared to low disturbance. The response of different insect taxa to the interactions of elevation and human disturbance varied. The findings imply that when formulating strategies for managing insect diversity, it is crucial to thoroughly consider the interaction of environmental factors and disturbance response of individual insect taxa.

Long-term spatial distribution and implication of black and brown carbon in the Tibetan Plateau.

Black carbon (BC) and brown carbon (BrC) over the high-altitude Tibetan Plateau (TP) can significantly influence regional and global climate change as well as glacial melting. However, obtaining plateau-scale in situ observations is challenging due to its high altitude. By integrating reanalysis data with on-site measurements, the spatial distribution of BC and BrC can be accurately estimated using the random forest algorithm (RF). In our study, the on-site observations of BC and BrC were successively conducted at four sites from 2018 to 2021. Ground-level BC and BrC concentrations were then obtained at a spatial resolution of 0.25° × 0.25° for three periods (including Periods-1980, 2000, and 2020) using RF and multi-source data. The highest annual concentrations of BC (1363.9 ± 338.7 ng/m3) and BrC (372.1 ± 96.2 ng/m3) were observed during Period-2000. BC contributed a dominant proportion of carbonaceous aerosol, with concentrations 3-4 times higher than those of BrC across the three periods. The ratios of BrC to BC decreased from Period-1980 to Period-2020, indicating the increasing importance of BC over the TP. Spatial distributions of plateau-scale BC and BrC concentrations showed heightened levels in the southeastern TP, particularly during Period-2000. These findings significantly enhance our understanding of the spatio-temporal distribution of light-absorbing carbonaceous aerosol over the TP.

Himalayas is barrier for transportation of light-absorbing particles from South Asia to inner Third Pole.

Through a comprehensive investigation into the historical profiles of black carbon derived from ice cores, the spatial distributions of light-absorbing impurities in snowpit samples, and carbon isotopic compositions of black carbon in snowpit samples of the Third Pole, we have identified that due to barriers of the Himalayas and remove of wet deposition, local sources rather than those from seriously the polluted South Asia are main contributors of light-absorbing impurities in the inner part of the Third Pole. Therefore, reducing emissions from residents of the Third Pole themselves is a more effective way of protecting the glaciers of the inner Third Pole in terms of reducing concentrations of light-absorbing particles in the atmosphere and on glaciers.

Warming and altered precipitation independently and interactively suppress alpine soil microbial growth in a decadal-long experiment.

Warming and precipitation anomalies affect terrestrial carbon balance partly through altering microbial eco-physiological processes (e.g., growth and death) in soil. However, little is known about how such processes responds to simultaneous regime shifts in temperature and precipitation. We used the 18O-water quantitative stable isotope probing approach to estimate bacterial growth in alpine meadow soils of the Tibetan Plateau after a decade of warming and altered precipitation manipulation. Our results showed that the growth of major taxa was suppressed by the single and combined effects of temperature and precipitation, eliciting 40-90% of growth reduction of whole community. The antagonistic interactions of warming and altered precipitation on population growth were common (~70% taxa), represented by the weak antagonistic interactions of warming and drought, and the neutralizing effects of warming and wet. The members in Solirubrobacter and Pseudonocardia genera had high growth rates under changed climate regimes. These results are important to understand and predict the soil microbial dynamics in alpine meadow ecosystems suffering from multiple climate change factors.

Hotspot mapping and risk prediction of fluoride in natural waters across the Tibetan Plateau.

Intake of high fluoride concentrations through water affects up to 1 billion people worldwide, and the Tibetan Plateau (TP) is one of the most severely affected areas. Knowledge regarding the high fluoride risk areas, the driving factors, and at-risk populations on the TP remains fragmented. We collected 1581 natural water samples from the TP to model surface water and groundwater fluoride hazard maps using machine learning. The geomean concentrations of surface water and groundwater were 0.26 mg/L and 0.92 mg/L, respectively. Surface water fluoride hazard hotspots were concentrated in the north-central region; high fluoride risk areas of groundwater were mainly concentrated in the southern TP. Hazard maps showed a maximum estimate of 15% of the total population in the TP (approximately 1.47 million people) at risk, and 500,000 people considered the most reasonable estimate. Critical environment driving factors were identified, in which climate condition was taken for the vital one. Under the moderate climate change scenario (SSP2.45) for 2089-2099, the high fluoride risk change rate differed inside the TP (surface water -24%-55% and groundwater -56%-50%), and the overall risk increased in natural waters throughout the TP, particularly in the southeastern TP.

Anthropogenic impact on airborne bacteria of the Tibetan Plateau.

The Tibetan Plateau is a pristine environment with limited human disturbance, with its aerosol microbiome being primarily influenced by the monsoon and westerly circulations. Additionally, the diversity and abundance of airborne microorganisms are also affected by anthropogenic activities, such as animal farming, agriculture, and tourism, which can lead to increased risks to the ecosystem and human health. However, the impact of anthropogenic activities on airborne microbes on the Tibetan Plateau has been rarely studied. In this work, we investigated the airborne bacteria of areas with weak (rural glacier) and strong human disturbance (urban building), and found that anthropogenic activities increased the diversity of airborne bacteria, and the concentration of potential airborne pathogens. Moreover, airborne bacteria in rural aerosols demonstrated significant differences in their community structure during monsoon- and westerly-affected seasons, while this pattern was weakened in urban aerosols. Additionally, urban aerosols enriched Lactobacillus sp. (member of genus Lactobacillus), which are potential pathogens from anthropogenic sources, whereas rural aerosols enriched A. calcoaceticus (member of genus Acinetobacter) and E. thailandicus (member of genus Enterococcus), which are both speculated to be sourced from surrounding animal farming. This study evaluated the impact of human activities on airborne bacteria in the Tibetan Plateau and contributed to understanding the enrichment of airborne pathogens in natural and anthropogenic background.

Microbial carbohydrate-active enzymes influence soil carbon by regulating the of plant- and fungal-derived biomass decomposition in plateau peat wetlands under differing water conditions.

Peatlands are important carbon sinks and water sources in terrestrial ecosystems. It is important to explore their microbial-driven water-carbon synergistic mechanisms to understand the driving mechanisms of carbon processes in peatlands. Based on macrogenomic sequencing techniques, located on the peatland of the eastern margin of the Tibetan Plateau with similar stand and different water conditions, we taken soil properties, microbiome abundance, CAZyme abundance and enzyme gene pathways as the object of study, investigated the characterization of soil microbial carbohydrate-active enzymes (CAZymes) under different water gradients in peatland. According to the results, these three phyla (Chloroflexi, Gemmatimonadetes, and Verrucomicrobia) differed significantly between water gradients. Under dried wetlands, the abundance of CAZymes involved in hemicellulose and glucan degradation increased by 3.0 × 10-5 and 3.0 × 10-6, respectively. In contrast, the abundance of CAZymes involved in chitin degradation decreased by 1.1 × 10-5 (p < 0.05). It highlights that regulating plant- and fungus-derived carbon metabolism processes by soil microorganisms in highland peatlands is a crucial mechanism for their response to water changes. Most plant-derived carbon fractions are regulated by soil enzymes (endo-beta 1,4-xylanase, alpha-L-arabinofuranosidase, and alpha-L-fucosidase) containing CAZymes functional genes. Additional findings in this enzyme gene pathway indicate that water changes that affect soil carbon fractions indirectly influence the three enzyme gene metabolic pathways related to plant carbon sources (the glycolysis/gluconeogenesis, other glycan degradation and amino sugar, and nucleotide sugar metabolism). Overall, this study highlights the significance of microbial CAZymes in highland peatland soil carbon processes and indicates that microbial conversion of plant and fungal biomass carbon is more sensitive to water changes.

Vegetation structural shift tells environmental changes on the Tibetan Plateau over 40 years.

Structural information of grassland changes on the Tibetan Plateau is essential for understanding alterations in critical ecosystem functioning and their underlying drivers that may reflect environmental changes. However, such information at the regional scale is still lacking due to methodological limitations. Beyond remote sensing indicators only recognizing vegetation productivity, we utilized multivariate data fusion and deep learning to characterize formation-based plant community structure in alpine grasslands at the regional scale of the Tibetan Plateau for the first time and compared it with the earlier version of Vegetation Map of China for historical changes. Over the past 40 years, we revealed that (1) the proportion of alpine meadows in alpine grasslands increased from 50% to 69%, well-reflecting the warming and wetting trend; (2) dominances of Kobresia pygmaea and Stipa purpurea formations in alpine meadows and steppes were strengthened to 76% and 92%, respectively; (3) the climate factor mainly drove the distribution of Stipa purpurea formation, but not the recent distribution of Kobresia pygmaea formation that was likely shaped by human activities. Therefore, the underlying mechanisms of grassland changes over the past 40 years were considered to be formation dependent. Overall, the first exploration for structural information of plant community changes in this study not only provides a new perspective to understand drivers of grassland changes and their spatial heterogeneity at the regional scale of the Tibetan Plateau, but also innovates large-scale vegetation study paradigm.

Genomic data provide a robust phylogeny backbone for Rhodiola L. (Crassulaceae) and reveal extensive reticulate evolution during its rapid radiation.

The Tibetan Plateau and adjacent mountain regions (TP; including the Tibetan Plateau, Himalaya, Hengduan Mountains and Mountains of Central Asia) harbor great biodiversity, some lineages on which may have undergone rapid radiations. However, only a few studies have investigated the evolutionary pattern of such diversification in depth using genomic data. In this study, we reconstructed a robust phylogeny backbone of Rhodiola, a lineage that may have undergone rapid radiation in the TP, using Genotyping-by-sequencing data, and conducted a series of gene flow and diversification analyses. The concatenation and coalescent-based methods yield similar tree topologies, and five well-supported clades were revealed. Potential gene flow and introgression events were detected, both between species from different major clades and closely related species, suggesting pervasive hybridization and introgression. An initial rapid and later slowdown of the diversification rate was revealed, indicating niche filling. Molecular dating and correlation analyses showed that the uplift of TP and global cooling in the mid-Miocene might have played an important role in promoting the rapid radiation of Rhodiola. Our work demonstrates that gene flow and introgression might be an important contributor to rapid radiation possibly by quickly reassembling old genetic variation into new combinations.

Validating HONO as an Intermediate Tracer of the External Cycling of Reactive Nitrogen in the Background Atmosphere.

In the urban atmosphere, nitrogen oxide (NOx═NO + NO2)-related reactions dominate the formation of nitrous acid (HONO). Here, we validated an external cycling route of HONO and NOx, i.e., formation of HONO resulting from precursors other than NOx, in the background atmosphere. A chemical budget closure experiment of HONO and NOx was conducted at a background site on the Tibetan Plateau and provided direct evidence of the external cycling. An external daytime HONO source of 100 pptv h-1 was determined. Both soil emissions and photolysis of nitrate on ambient surfaces constituted likely candidate mechanisms characterizing this external source. The external source dominated the chemical production of NOx with HONO as an intermediate tracer. The OH production was doubled as a result of the external cycling. A high HONO/NOx ratio (0.31 ± 0.06) during the daytime was deduced as a sufficient condition for the external cycling. Literature review suggested the prevalence of high HONO/NOx ratios in various background environments, e.g., polar regions, pristine mountains, and forests. Our analysis validates the prevalence of external cycling in general background atmosphere and highlights the promotional role of external cycling regarding the atmospheric oxidative capacity.

The soil-air exchange of OCPs and PCBs in the Tibetan Plateau: Emphasis on episodic transport of unintentionally produced PCBs.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in paired ambient and surface air fugacity samples were measured in the Tibetan Plateau (TP) from 2019 to 2022. The air concentrations of previously intentionally produced chemicals like dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) declined. Their soil-air exchange direction ranged from equilibrium to volatilization, suggesting that the TP is acting as a secondary source of most OCPs and PCBs with the pollution alleviation. However, considerably high atmospheric levels of PCB-11, an indicator of unintentionally produced PCBs (UP-PCBs), were recorded in the southern TP. Strong episodic long-range atmospheric transport (LRAT) and deposition of PCB-11 events took place mostly in summer. Those events associated with winds from potential sources and less rainfall interception along the air mass transport routes accounted for a significant fraction of overall atmospheric deposition in the TP. Meanwhile, cryoturbation and plowing are suspected to be important factors contributing to the reemission of PCB-11 from surface soil. The high abundance of PCB-11 and strong deposition/evaporation events highlights potential environmental and health risks of UP-POPs in the TP.

Li isotopic seasonality in a small catchment at the northeastern Tibetan Plateau: Roles of hydrology and temperature dependency.

Silicate weathering is critical to sustain our habitable planet. Lithium (Li) isotopes enable us to investigate the nature of silicate weathering. A number of riverine Li isotope (δ7Lirw) investigations have been made from polar to equatorial terrains, but there remains no consensus about the controlling mechanisms of both weathering and δ7Lirw. Here we investigated δ7Lirw response to climate by collecting weekly river water samples in a small catchment (the Buha River within the Lake Qinghai basin) on the northeastern Tibetan Plateau, with stable tectonic, lithology, and topography. In the hydrology year of 2007 of the Buha River, we find that during the dry seasons, δ7Lirw ratios show temperature dependency typically, when the groundwater fed the river. During the monsoon seasons, δ7Lirw were obviously lower than the temperature dependency predicted values, when abundant rock dissolved and thereby fresh Li release into rivers. We propose that the hydrology and temperature dependency together play important roles in regulating δ7Lirw ratios in such an alpine small catchment. The mechanism is that long residence time facilitates the equilibrium chemical and Li isotopic fractionation during the dry seasons, so a temperature dependency of δ7Lirw is achieved. In contrast, rapid erosion and weathering contribution of fresh rock-like δ7Li to river water would significantly decrease δ7Lirw ratios during the monsoon seasons. This hypothesis can better interpret previously reported data of seasonal δ7Lirw variation, as a superposition between temperature dependency and hydrology regulation on silicates weathering in the small catchments besides tectonics.

Time-series monitoring of river hydrochemistry and multiple isotope signals in the Yarlung Tsangpo River reveals a hydrological domination of fluvial nitrate fluxes in the Tibetan Plateau.

Nutrient element cycling in the Tibetan Plateau, the highest and largest plateau in the world, is sensitive to anthropogenic disturbances and climate change. Studying the spatiotemporal dynamics of reactive nitrogen (N) - predominantly in the form of nitrate (NO3-) - in the plateau is crucial to understand the regional and global N cycles and their feedbacks with climate change. We conducted the first weekly frequency hydro-geochemical monitoring (i.e., discharge, water chemistry, and multiple isotopes) from the upper to the lower reaches of the Yarlung Tsangpo River, the largest river in the plateau, in pronounced wet/dry cycles to reveal the biogeochemical transformations and fluvial fluxes of NO3- response to hydrologic condition. Relative stable NO3- concentration and significant linear correlations between the fluvial NO3- fluxes and the discharge were observed, suggesting that a significant potential NO3- source counterbalanced the diluting effects during the rainy season. The negative correlations between δ15N-NO3- and discharge/NO3- fluxes suggested that the increasing NO3- flux respond to the increasing discharge was mainly from water leaching of 15N-depleted soil sources, rather than 15N-enriched sewage. The isotopic mixing model calculation showed that NO3- fluxes were largely generated in the relatively densely populated middle reaches (56%), of which 74% were from soil sources. The fluxes of the soil sources showed large seasonal variation and peaked in August, with hydrological condition as the primary driver. Based on the critical findings, we put forward a NO3- export conceptual model that integrated anthropogenic and climatic forcings and classified NO3- export mechanisms in river basins into transport-limited and generation-limited regimes. In a transport-limited regime that characterized most river basins in the Tibetan Plateau, fluvial NO3- flux presented a linearly relationship in response to runoff variation. In contrast, in a generation-limited regime, the flux would be largely dependent on the thermodynamic of nitrification.

Spatiotemporal characteristics of surface water resources in the Tibetan plateau: Based on the produce water coefficient method considering snowmelt.

The Tibetan Plateau (TP), with its widely distributed cryosphere elements and the source of 12 major rivers, is a strategic area for Asian water resource generation, storage, and migration. Because of the unique surface water resources (SWR) characteristics, multi-phase and multiple sources, the hydrological process here is extremely complex. Coupled with the lack of measured data, the SWR in the TP has not been quantified refinedly. Thus, an improved large-scale SWR assessment method was proposed based on the produce water coefficient (PWC) method considering snowmelt. It overcomes the challenge of scarcity of data on ungauged regions. As climate changes, long-sequence dynamic evaluation of SWR can be achieved refinedly. As a result, the datasets of the amount of SWR of the level 4 water resources zones (WRZ) in the TP from 1956 to 2018 were obtained by calculating the PWC and snowmelt. Then spatiotemporal characteristics of SWR in the TP were analyzed. The results showed that the annual average SWR of the TP has been increasing over the past 60 years. Affected by climate change, the SWR in the Eastern TP increased, while the SWR in the Western TP (western part of the Karakoram Mountains) decreased significantly. The findings could be beneficial for water resource security and sustainable development in Asia. This revised method, which well avoided the misestimation of classical methods, could be used to evaluate the large-scale SWR for cold and ungauged regions.

Plant Community Traits Respond to Grazing Exclusion Duration in Alpine Meadow and Alpine Steppe on the Tibetan Plateau.

Grazing exclusion has been a primary ecological restoration practice since the implement of "Returning Grazing Land to Grassland" program in China. However, the debates on the effectiveness of grazing exclusion have kept for decades. To date, there has been still a poor understand of vegetation restoration with grazing exclusion duration in alpine meadows and alpine steppes, limiting the sustainable management of grasslands on the Tibetan Plateau. We collected data from previous studies and field surveys and conducted a meta-analysis to explore vegetation restoration with grazing exclusion durations in alpine meadows and alpine steppes. Our results showed that aboveground biomass significantly increased with short-term grazing exclusion (1-4 years) in alpine meadows, while medium-term grazing exclusion (5-8 years) in alpine steppes (P < 0.05). By contrast, belowground biomass significantly increased with medium-term grazing exclusion in alpine meadows, while short-term grazing exclusion in alpine steppes (P < 0.05). Long-term grazing exclusion significantly increased belowground biomass in both alpine meadows and alpine steppes. medium-tern, and long-term grazing exclusion (> 8 years) significantly increased species richness in alpine meadows (P < 0.05). Only long-term GE significantly increased Shannon-Wiener index in plant communities of alpine steppes. The efficiency of vegetation restoration in terms of productivity and diversity gradually decreased with increasing grazing exclusion duration. Precipitation significantly positively affected plant productivity restoration, suggesting that precipitation may be an important factor driving the differential responses of vegetation to grazing exclusion duration in alpine meadows and alpine steppes. Considering the effectiveness and efficiency of grazing exclusion for vegetation restoration, medium-term grazing exclusion are recommended for alpine meadows and alpine steppes.

Coupling of decreased snow accumulation and increased light-absorbing particles accelerates glacier retreat in the Tibetan Plateau.

Most glaciers in the Tibetan Plateau (TP) are experiencing dramatic retreat, which is resulting in serious environmental and ecological consequences. In addition to temperature increases, increased light-absorbing particles (LAPs) and decreased precipitation were proposed to, independently, play important roles in reducing glacier accumulation. Based on investigations of effect from an extremely low precipitation event in the TP and surrounding regions caused by La Niña from October 2020 to April 2021, a new mechanism was provided. It was shown that decreased precipitation during study period leaded to both low snow accumulation and high LAP concentrations in snow on glacier surfaces in the TP. This phenomenon will strongly enhance earlier and accelerated glacier melt in this critical region and needs to be considered in future related studies.

Perfluoroalkyl substances in precipitation from the Tibetan Plateau during monsoon season: Concentrations, source regions and mass fluxes.

Atmospheric wet deposition is an important process for the occurrence of perfluoroalkyl substances (PFASs) in polar/remote mountain regions; however, there are limited data on PFASs in precipitation from the Tibetan Plateau (TP). Precipitation (rain from May to October 2017) was therefore collected across the TP to investigate the concentrations, composition profiles, sources, and fluxes of perfluoroalkyl acids (PFAAs). The average ∑PFAA concentrations ranged from 212.3 pg L-1 to 547.7 pg L-1, and perfluoroalkyl carboxylic acids (PFCAs) accounted for 87% of the measured PFAAs (mean value). Significant positive associations (p < 0.05) were found for most PFCAs in the southeast TP, indicating that they may come from similar sources. The monthly PFAA deposition flux ranged from 12.6 to 68.9 ng m-2 month-1, decreasing from east to west. As climate of the eastern TP is controlled mainly by the Indian monsoon, indicating that the Indian monsoon plays an important role in delivering PFAAs to the TP. PCA (principal component analysis) combined with back-trajectory analysis was used to estimate the atmospheric transport pathways, and the PSCF (potential source contribution function) model was applied to define the potential source regions of individual PFAAs. The results suggested that northeast India, Bangladesh, and southern Nepal are the potential sources of C4-C7 PFCAs; C8-C10 PFCAs are more influenced by emissions from southern Nepal and Bhutan; while the source regions of long-chain PFCAs (C11-C12) can be attributed to northern India and Pakistan. Specifically, PFOS (perfluorooctane sulfonic acid) has a local contribution from the central TP.

Adventurous tourism: acclimatization problems and decisions in trans-boundary travels.

As the twenty-first-Century Maritime Silk Road tourism program aims on development of new tourist routes with special interest on the polar regions of the Arctic and the Antarctic, as well as the Tibetan Plateau, management of climate risks in travels and their reduction is an important issue for achievement of its goals at national and local levels. Acclimatization is crucial for adventurous tourists, and especially for those traveling to extremely cold and highly elevated environments, when climate and weather in tourist destination differ significantly from those at home. The Acclimatization Thermal Strain Index for Tourism (ATSIT) is designed and used to measure numerically the physiological expenses a traveler pays during the acclimatization process. The purpose of the present study is to examine acclimatization consequences for travels from Beijing, capital of China, to destinations at the Arctic, the Antarctic, and the Tibetan Plateau, collectively referred to as the 3Polar regions, during the main seasons of winter and summer, and back. The results show that acclimatizing to cold involves greater physiological strain than adjustment to heat. Acclimatization load in winter is low for all travels from Beijing and back home. ATSIT projections detect the most harmful degree of discomfort for summer travels from Beijing. The greatest acclimatization impact comes when changing locales from hot and humid to cold and dry climatic conditions, which might cause high and very high physiological strain. Moreover, as many destinations in the 3Polar regions, mostly in the Tibetan Plateau, are located in mountains, a special acclimatization plan is required to weaken the threat of mountain sickness. The results will be helpful for warning stakeholders and the decision makers in the tourism sector of economies, and are expected to be translated into action for the development of proper intervention procedures in health control, to minimize population loss.

Analysis of Multiplicity of Hypoxia-Inducible Factors in the Evolution of Triplophysa Fish (Osteichthyes: Nemacheilinae) Reveals Hypoxic Environments Adaptation to Tibetan Plateau.

HIF (Hypoxia-inducible factor) gene family members function as master regulators of cellular and systemic oxygen homeostasis during changes in oxygen availability. Qinghai-Tibet Plateau is a natural laboratory for for long-term hypoxia and cold adaptation. In this context, T. scleroptera that is restricted to >3500 m high-altitude freshwater rivers was selected as the model to compare with a representative species from the plain, P. dabryanus. We cloned different HIF-α and carried out a phylogenetic analysis from invertebrates to vertebrates for identifying HIF-α genes and analyzing their evolutionary history. Intriguingly, the HIF-α has undergone gene duplications might be due to whole-genome duplication (WGD) events during evolution. PAML analysis indicated that HIF-1αA was subjected to positive selection acted on specific sites in Triplophysa lineages. To investigate the relationship between hypoxia adaptation and the regulation of HIF-α stability by pVHL in plateau and plain fish, a series of experiments were carried out. Comparison the luciferase transcriptional activity and protein levels of HIF-αs and the differing interactions of HIF-αs with pVHL, show clear differences between plateau and plain fish. T. scleroptera pVHL could enhance HIF-α transcriptional activity under hypoxia, and functional validation through pVHL protein mutagenesis showed that these mutations increased the stability of HIF-α and its hetero dimerization affinity to ARNT. Our research shows that missense mutations of pVHL induced evolutionary molecular adaptation in Triplophysa fishes living in high altitude hypoxic environments.

Alpine grassland plants grow earlier and faster but biomass remains unchanged over 35 years of climate change.

Satellite data indicate significant advancement in alpine spring phenology over decades of climate warming, but corresponding field evidence is scarce. It is also unknown whether this advancement results from an earlier shift of phenological events, or enhancement of plant growth under unchanged phenological pattern. By analyzing a 35-year dataset of seasonal biomass dynamics of a Tibetan alpine grassland, we show that climate change promoted both earlier phenology and faster growth, without changing annual biomass production. Biomass production increased in spring due to a warming-induced earlier onset of plant growth, but decreased in autumn due mainly to increased water stress. Plants grew faster but the fast-growing period shortened during the mid-growing season. These findings provide the first in situ evidence of long-term changes in growth patterns in alpine grassland plant communities, and suggest that earlier phenology and faster growth will jointly contribute to plant growth in a warming climate.