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Aims: It has been assumed that montane species will undergo upslope shifts in response to climate warming and their range sizes are therefore predicted to decrease. However, this view has been challenged because a recent study (Elsen & Tingley, 2015) indicated that land surface area increases with increasing altitude in some mountains. To test this prediction, we used one of the world's biodiversity hotspots as a study system to examine overall patterns of plant distribution shift in response to climate warming. Location: The Hengduan Mountains and adjacent regions. Methods: Based on distribution data for 151 species at a resolution of 2.5 arc minutes, we employed ecological niche modelling to model their distributions under the climatic conditions of the Last Glacial Maximum, Current (2017), and 2050 separately. We examined the distributional shifts of these species, especially with respect to altitude and range size, in response to two periods of stepwise climate warming. Results: All the montane plants sampled shifted upward during the two warming stages, but not only northward, some shifted westward or in other directions. In contrast with the expected consistent loss of range when shifting upward, 63.6% of the plants expanded their range size continuously since the LGM. Only 11.9% of the plants contracted their range size continuously from the LGM to 2050. Estimates of species richness in the regions studied changed greatly, but in an unbalanced manner, from the LGM to the Current and from the Current to 2050. Main conclusions: Numerous montane plants in the Hengduan Mountains are predicted to expand their range sizes as they shift upslope in response to climate warming. Our results highlight the possibility that more available land surface area due to the heterogeneous topography along altitudinal gradients and the adjacent large Qinghai-Tibet Plateau sensu stricto can mediate the range loss of the montane plants under climate warming. These findings are crucial for estimating the future range sizes of plants and planning biodiversity protection for mountain ecosystems under the anticipated warming of the world's climate.

Aim: We investigated the historical biogeography and diversification of Gentiana L. (Gentianaceae). Our study depicts the origin and dispersal routes of this alpine genus, and the role of the uplift of the Qinghai—Tibet Plateau (QTP) and past climate changes as triggers for its diversification. Location: Tibeto-Himalayan region and world-wide mountain habitats. Methods: Our sampling represents more than 50% of the extant Gentiana species, including all sections across their entire geographical ranges. We investigated the evolutionary history of Gentiana using phylogenetic reconstructions (maximum likelihood and Bayesian inference) of ITS, atpB—rbcl and trnL—trnF sequences, as well as molecular dating with BEAST. We tested two approaches of ancestral area reconstructions (DEC, DIVA) in BioGeoBEARS and investigated diversification rates using BAMM. Results: The common ancestor of Gentiana and subtribe Gentianinae lived in the QTP region at around 34 (25—45) million years ago (Ma), and 40 (29—52) Ma respectively. From the surroundings of the QTP, Gentiana lineages dispersed to eastern China, Taiwan, Europe, North and South America, Australia and New Guinea, from mid-Miocene onward (c. 15 Ma—present), with only one older dispersal event to Europe (c. 37—21 Ma). Diversification rates gradually increased over time, and two switches of diversification rates were identified in Gentianinae (c. 7 Ma, simultaneously in the Pneumonanthe/Cruciata lineage and in Tripterospermum). Main conclusions: Gentiana existed in the QTP region throughout most of its uplift history following the India-Asia collision. This region acted as the primary source area for dispersals to many areas of the world. Because steady increase in diversification rates coincides with the extension of the QTP, we argue that the museum theory rather than the explosive radiation theory prevails for gentians in this region, although rare shifts of diversification rates are associated with niche shifts across the alpine/subalpine ecotone.

The South Qiangtang block of the Qinghai‐Tibet Plateau represents an area critical to understanding the late Paleozoic and early Mesozoic history of the Tethyan realm, but its drift history remains poorly constrained. Here we report a new quantitative paleogeographic constraint for the South Qiangtang block from a paleomagnetic study of Late Triassic volcanic rocks of the Xiaoqiebao Formation. A characteristic remanent magnetization isolated from 25 sites passes both fold‐ and reversal tests, and likely represents a primary magnetization. On the basis of these data, we estimate that the South Qiangtang block occupied a paleolatitude of 30.1 ± 4.6°N at ca. 222 Ma. When combined with existing paleomagnetic constraints, these new results indicate that the South Qiangtang block (and other “Cimmerian” blocks) moved rapidly northward (in true latitude) between the middle Permian and Late Triassic. Our new data further suggest that the southern branch of the Paleo‐Tethys (Longmuco‐Shuanghu Ocean) likely closed by the mid‐Late Triassic. Plain Language Summary The Paleo‐Tethys was a major eastward‐widening oceanic domain that separated eastern Gondwana and eastern Laurasia during Carboniferous‐Permian time. The eventual disappearance of this ocean coincided with the amalgamation of the terranes comprising the modern Qinghai‐Tibet Plateau. However, the plate kinematic history that led up to this suturing remains poorly constrained. In particular, the South Qiangtang block, which is thought to have formed the southern margin of the system, is a key area in need of additional constraints. In this work, we present new paleomagnetic results which indicate that the South Qiangtang block drifted rapidly northward between the middle Permian and Late Triassic (at an average south‐north speed of ∼13.4 cm/yr) to arrive to a paleolatitude of 30°N by 222 Ma. Such a position suggests that the southern branch of the Paleo‐Tethys (Longmuco‐Shuanghu Ocean) may have closed by this time. Key Points The South Qiangtang block was located at ∼30°N in the Late Triassic In the Permo‐Triassic the South Qiangtang block drifted rapidly northward at ∼13.4 cm/yr The Longmuco‐Shuanghu Ocean closed no later than ca. 222 Ma

Attributing intensification extreme precipitation to anthropogenic factors on the regional scale is challenging, given the large fluctuations and the complexity of quantifying interactions among these anthropogenic factors. Here, we propose a new variance‐based method to investigate the roles of human‐induced greenhouse gas (GHG), aerosol (AER), and their interactions (GA) in shaping extreme precipitation on the Qinghai‐Tibet Plateau (QTP) at stational scale. In terms of contribution, GHG has the greatest impact on total wet‐day precipitation and simple daily intensity. In terms of significance, GA, and AER exert significant effects on all 10 extreme indices (P; < 0.05) over 48.3% and 44.8% of all stations, while GHG affects less (25.9%). Overall, GHG is not the only dominant factor, and GA and AER are expected to play vital roles in intensifying extreme precipitation over the QTP under SSP2‐4.5. These findings challenge the conventional insights that GHG is the primary anthropogenic driver of extreme precipitation. Plain Language Summary Greenhouse gas (GHG) has long been regarded as the primary anthropogenic driver of the intensification of extreme precipitation. However, extreme precipitation is closely linked to the complex interplay of various anthropogenic influences, with contributions varying across regions due to differences in longitude, latitude, and altitude. Here, we propose a new method to robustly quantify the contributions of GHG, AER, and GA to extreme precipitation at each station on the Qinghai‐Tibet Plateau (QTP). The results show that the majority of the stations quantified by this method are statistically significant. Importantly, we find that complex interactions of GHG and AER will shape extreme precipitation over the QTP. These findings challenge the traditional understanding of climate change attributed solely to GHG and prompt a reconsideration of whether reducing GHG alone could effectively mitigate climate change. Key Points We propose a new variance‐based factorial analysis method to quantify contributions of anthropogenic factors at each meteorological station over Qinghai‐Tibet Plateau (QTP) Extreme precipitation over the QTP is projected to increase in the upcoming century The interaction between greenhouse gas and aerosol would play a key role in intensification extreme precipitation over QTP under SSP2‐4.5

Aim Geologically dynamic areas often harbour remarkable levels of biodiversity. Among other factors, mountain building is assumed to be a precondition for species radiation, and yet, the potential role of immigration as a source of biodiversity prior to radiation is often neglected. Here, we studied the biogeographical history of the large genus Saxifraga to unravel the role played by the Qinghai-Tibet Plateau (QTP) for the diversification of this genus and to understand factors that have led to the establishment of high biodiversity in and around this region. Location QTP and surrounding mountain ranges and worldwide distribution range of Saxifraga. Methods Using a total of 420 taxa (321 ingroup taxa) comprising more than 60% of extant Saxifraga species, we studied the evolutionary history of Saxifraga by performing phylogenetic analyses (maximum likelihood and Bayesian inference on nuclear ITS and plastid trnL-trnV, matK sequences), divergence time estimation (using uncorrelated log-normal clock models and four fossil constraints in beast) and ancestral range estimation (using BioGeoBEARS). Results Saxifraga originated in North America around 74 (64–83) Ma, dispersed to South America and northern Asia during its early diversification and colonized Europe and the QTP region by the Late Eocene. The QTP region was colonized several times independently, followed in some lineages by rapid radiations, temporally coinciding with recent uplifts of the Hengduan Mountains at the southeastern fringe of the QTP. Subsequently, several lineages dispersed out of Tibet. Main conclusions Immigration, recent rapid radiation and lineage persistence were all important processes for the establishment of a rich species stock of Saxifraga in the QTP region. Because floristic exchanges between the neighbouring areas and the QTP region were bi-directional, the spatio-temporal evolution of Saxifraga contrasts with the 'out of QTP' pattern, which has often been assumed for northern temperate plants.

The active layer over permafrost plays a significant role in surface energy balance, hydrologic cycle, carbon fluxes, ecosystem, and landscape processes and on the human infrastructure in cold regions. Over a period from 1995 to 2007, a systematic soil temperature measurement network of 10 sites was established along the Qinghai‐Tibetan Highway. Soil temperatures up to 12 m depth were continuously measured semimonthly. In this study, we investigate spatial variations of active layer thickness (ALT) and its change over the period of record. We found that ALT can be estimated with confidence using semimonthly soil temperature profiles compared to those determined from available daily soil temperature profiles over the Qinghai‐Tibetan Plateau. The primary results demonstrate that long‐term and spatially averaged ALT is ∼2.41 m with a range of 1.32–4.57 m along the Qinghai‐Tibetan Highway. All monitoring sites show an increase in ALT over the period of their records. The mean increasing rate of ALT is ∼7.5 cm/yr. ALT shows a closely positive correlation with the thawing index of air temperature on the plateau. We estimated ALT using the thawing index over a period from 1956 to 2005 near the Wudaoliang Meteorological Station in the northern plateau. ALT had no or very limited change from 1956 to 1983 and a sharp increase of ∼39 cm from 1983 to 2005. The magnitude of ALT increase is greater in the warm permafrost region than in the cold permafrost region. The primary control of increase in ALT is caused by an increase in summer air temperature, whereas changes in the winter air temperature and snow cover condition play no or a very limited role.

Plateau pikas, small mammals native to the Qinghai‐Tibet Plateau (QTP), create bare patches through burrowing. No previous assessment exists on their impact on permafrost. This study fills this gap by simulating hypothetical scenarios in the Three Rivers Headwaters Region of the QTP using the Noah‐MP model for the plant growing seasons during 2015–2018. Our findings reveal a significant increase in soil temperature in the active layer due to pika‐induced bare patches, particularly during July–August. The average temperature rise at 2.5 cm depth was 0.36°C in permafrost regions and 0.29°C in seasonally frozen ground regions during August. Minimal impact on unfrozen water content was observed, with a slight increase in deep soil layers in permafrost regions, and negligible in seasonally frozen areas. These findings underscore the previously unexplored influence of pika burrowing on permafrost temperature, suggesting a potential risk of accelerating permafrost degradation, especially in permafrost‐dominated regions. Plain Language Summary On the vast Qinghai‐Tibet Plateau (QTP), plateau pikas are actively excavating burrows, creating bare patches of exposed earth within the typical grassland landscape. These seemingly minor disturbances can have significant consequences, as they alter heat and water conditions within the underlying permafrost. However, a comprehensive understanding of how these pika‐made patches impact the permafrost remains elusive. To address this gap, our study employed a computer model and simulating scenarios with and without pika patches in the ecologically fragile Three Rivers Headwaters Region (TRHR) of the QTP. We found that the pika‐induced bare patches significantly raised permafrost temperatures, especially in the shallow soil layers. During August, the peak pika activity month, the average soil temperature at a depth of 2.5 cm increased by 0.36°C in permafrost zones and 0.29°C in seasonally frozen ground zones. While the patches had minimal impact on unfrozen water content in the active layer, the temperature rise in permafrost warrants future concern. Key Points Bare patches due to plateau pika burrowing warmed permafrost, particularly during peak activity months and in shallow soil layers Pika bare patches warmed permafrost and seasonally frozen ground by about 0.36°C–0.29°C, respectively, at a 2.5 cm depth in August Pika‐induced bare patches had negligible impact on the unfrozen water content in the active layer of permafrost

As the Earth's Third Pole and the Asian water tower, the Qinghai‐Tibet Plateau (QTP) plays a key role in global climate regulation and biodiversity maintenance. Living in harmony with nature is vital for local and global sustainable development. Current research on the conflicted or coordinated relationship between humans and nature on the QTP at a fine spatial scale remains limited. To fill the gap, we developed the human activity intensity index (HAI) and eco‐environmental quality index (EQI) at 1‐km resolution and proposed a four‐quadrant diagram approach to explore the dynamics between them. The results show a coordinated development on the QTP as the HAI and EQI both increased from 2000 to 2020, and the ratio of coordinated areas to conflicted areas was 5:1. High HAI areas were mainly in big cities such as Xining, Lhasa, Haidong, Xigaze, and along traffic lines. The significant conflicted areas were mainly outside the Lhasa metropolitan, south of the Hengduan Mountains, and along some new roads, and reduced by 8% between 2000–2010 and 2010–2020. The area of high HAI but low EQI was the smallest proportion, mainly in southern Qinghai Lake, southern Brahlung Zangbo River, Gobi oases, and western transport lines, but it implies the highest risk of ecosystem degradation. This research expands the fundamental methodology to address complex human‐natural relationships and provides implications for the sustainable development of fragile ecosystems. Plain Language Summary The Qinghai‐Tibet Plateau (QTP), with an average altitude of over 4,000 m and 13 million residents, is the source of the nine rivers in Asia, providing fresh water, food, and other ecosystem services to more than 1.5 billion people, and is known as the Earth's Third Pole and Asian water tower. However, research on the relationship between humans and nature in that region is limited, especially at a fine spatial scale. To fill the gap, we developed the human activity intensity index (HAI) and eco‐environmental quality index (EQI) at 1‐km resolution and proposed a four‐quadrant diagram approach to explore the dynamics between them, addressing potential risks and sustainability pathways. We find that the relationship between humans and nature on the QTP tends to be harmonious from 2000 to 2020. The significant conflicted areas were mainly outside the Lhasa metropolitan, south of the Hengduan Mountains, and along new roads, and reduced by 8% between 2000–2010 and 2010–2020. However, the plateau's fragile ecosystem still faces great challenges with population growth, urbanization, infrastructure construction, and the threat of global climate change. This work expands the fundamental methodology and may support fine ecological restoration and environmental management for local governments. Key Points Human activity intensity and eco‐environmental quality were measured at the grid scale of 1‐km resolution on the Earth's Third Pole We proposed a four‐quadrant diagram approach to identify dynamic relationships between humans and nature Socioeconomic development and eco‐environment on the QTP tend to be coordinated during 2000–2020

Global warming has led to permafrost degradation worldwide. The Qinghai‐Tibet Plateau (QTP) hosts most of the world's alpine permafrost, yet its impending changes remain largely unclear, thereby affecting regional hydrological and ecological processes and the global carbon budget. By employing a land surface model adapted to simulate frozen ground, and using state‐of‐the‐art multi‐model and multi‐scenario data from the Coupled Model Intercomparison Project Phase 6, changes in permafrost distribution and its thermal regimes on the QTP are systematically predicted under various shared socioeconomic pathways (SSPs). Projections for SSP2‐4.5, SSP3‐7.0, and SSP5‐8.5 show that most of the continuous permafrost region of the QTP will persist through 2050. Much of the permafrost is likely to degrade in the late 21st century, with projected area losses of 44 ± 4%, 59 ± 5%, and 71 ± 7%, respectively, by 2100. In particular, the Three Rivers Source region in the central eastern part of the QTP is a key area of permafrost degradation, where permafrost is most vulnerable and degradation occurs earliest. The mean annual ground temperature of QTP permafrost will increase by 0.8 ± 0.2°C, 2.0 ± 0.3°C, and 2.6 ± 0.3°C under SSP2‐4.5, SSP3‐7.0, and SSP5‐8.5, respectively, and the active layer thickness will increase by 0.7 ± 0.1 m, 1.5 ± 0.3 m, and 3.0 ± 1.0 m, respectively. The surviving permafrost under SSP3‐7.0 and SSP5‐8.5 will be thermally unstable, which is a clear warning sign of complete disappearance. The analysis of permafrost sensitivity to climate change signifies that alpine permafrost on the QTP has low resilience to climate change, in contrast to permafrost in pan‐Artic high latitudes. Plain Language Summary The Qinghai‐Tibet Plateau (QTP) contains the largest area of alpine permafrost on Earth. It has been observed that permafrost on the QTP has been substantially degraded due to drastic climate warming. Existing prediction studies have consistently concluded that QTP permafrost will degrade with climate warming, but there is no consensus on the extent of degradation. To date, there have been no studies employing land surface models to predict future changes in QTP permafrost based on the latest Coupled Model Intercomparison Project Phase 6 data. Here, based on climate outputs from multi‐model projections under the Shared Socioeconomic Pathways, we used a land surface model adapted to frozen ground modeling to simulate future changes in permafrost distribution and its thermal regimes on the QTP, and evaluated permafrost responses to various scenarios of future climate change. The results show that much of the QTP permafrost will degrade in the late 21st century, and the Three Rivers Source region is a key area of future permafrost degradation, where permafrost is most vulnerable and degradation will occur earliest. Our results will help improve understanding of future changes in QTP permafrost as the climate warms and provide scientific support for climate change adaptation policies and sustainable regional development. Key Points By 2100, permafrost area will shrink by 44 ± 4%, 59 ± 5%, and 71 ± 7% for SSP2‐4.5, SSP3‐7.0 and SSP5‐8.5, respectively Permafrost in the Three Rivers Source region is the most vulnerable and begins to degrade the earliest Under SSP3‐7.0 and SSP5‐8.5, the surviving permafrost becomes unstable and is on the verge of disappearing by 2100