Identifying climate refugia for wild yaks (Bos mutus) on the Tibetan Plateau.

ABSTRACT

Climate change is threatening fragile alpine ecosystems and their resident ungulates, particularly the wild yak (Bos mutus) that inhabits alpine areas between the tree line and glaciers on the Tibetan Plateau. Although wild yaks tend to shift habitats in response to changes in climatic factors, the precise impacts of climate change on their habitat distribution and climate refugia remain unclear. Based on over 1000 occurrence records, the maximum entropy (MaxEnt) algorithm was applied to simulate habitat ranges in the last glacial maximum (LGM), Mid-Holocene, current stage, and three greenhouse gas emission scenarios in 2070. Three habitat patches were identified as climate refugia for wild yaks that have persisted from the LGM to the present and are projected to persist until 2070. These stable areas account for approximately 64% of the current wild yak habitat extent and are sufficiently large to support viable populations. The long-term persistence of these climate refugia areas is primarily attributed to the unique alpine environmental features of the Tibetan Plateau, where relatively stable arid or semi-arid climates are maintained, and a wide range of forage resource supplies are available. However, habitat loss by 2070 caused by insufficient protection is predicted to lead to severe fragmentation in the southeastern and northwestern Kunlun, Hengduan, central-western Qilian, and southern Tanggula-northern Himalaya Mountains. Habitat disturbance has also been caused by increasing anthropogenic effects in the southern Tanggula and northern Himalaya Mountains. We suggest that sufficient protection, transboundary cooperation, and community involvement are required to improve wild yak conservation efforts. Our combined modeling method (MaxEnt-Zonation-Linkage Mapper-FRAGSTAT) can be utilized to identify priority areas and linkages between habitat patches while assessing the conservation efficiency of protected areas and analyzing the coupled relationship between climate change and anthropogenic impacts on the habitat distribution of endangered species.