Climate-induced habitat shifts and vulnerability of the Tibetan brown bear (Ursus arctos pruinosus) in the Xizang Autonomous Region, China

Climate change is increasingly reshaping the spatial distribution of biodiversity, particularly affecting large-bodied umbrella species in high-altitude ecosystems. We evaluated the potential impacts of climate change on the distribution and habitat vulnerability of the Tibetan brown bear ( Ursus arctos pruinosus ), an umbrella species in the Xizang Autonomous Region. We used the MaxEnt model to predict suitable habitat under current and future climate conditions, incorporating outputs from three General Circulation Models across three emission scenarios. Habitat vulnerability was assessed using vulnerability indices based on changes in suitable habitat. Circuitscape was employed to identify ecological corridors. Our results revealed a substantial contraction of suitable habitat under future scenarios, with habitat losses most pronounced in Qamdo and Shannan, where reductions exceed 70–80 % under RCP8.5. Overall, suitable habitat is projected to decrease by 35.87 %, with 39.36 % of current habitat classified as vulnerable and only 5.45 % identified as newly emerging. Climate refugia, particularly in Ngari, may offer critical conservation value. Furthermore, suitable habitat remains concentrated between 4400–5400 m, indicating strong altitudinal constraints. Ecological corridor analyses suggest that the future corridors become increasingly fragmented and sparsely distributed. These findings underscore the urgency of climate-informed conservation strategies to mitigate habitat loss and fragmentation for high-altitude species on the Qinghai-Tibet Plateau.