Synergistic effects of climate and land use change on khulan (Equus hemionus hemionus) habitat in China

Climate and land use change are the primary drivers causing the reduction of habitat range for many species worldwide, especially wide-ranging and large-bodied ungulates. For instance, khulan (Equus hemionus hemionus), a flagship species inhabiting desert regions of Asia, exhibits heightened vulnerability to habitat loss and fragmentation due to their extensive habitat requirements. We simulated suitable khulan habitats in China across 20 scenarios, including the past (1980-2000), current (2001-2022), and future (2050 s and 2070 s) climate and land use change scenarios. For each scenario, we identified the suitable habitat area and evaluated the effectiveness of protected areas (PAs). Our findings revealed a decline in khulan habitat area from 133,006 km2 in the past to 60,141 km2 at present. Future scenarios indicate further reductions in potential khulan habitat, with more negative impacts resulting from climate change than land use change. Northern Xinjiang is expected to persist as a primary area of both in-situ and ex-situ refugia for khulan in future scenarios. Although suitable habitat within existing PAs is smaller than that outside, the rates of habitat loss and fragmentation outside the PAs surpass those inside PAs. These findings emphasize the importance of effective management strategies for PAs as crucial goals for ongoing conservation efforts for the khulan. Our models suggest that future suitable habitat for khulan will be situated along the international border between China and Mongolia, adjacent to protected areas in Mongolia utilized by khulan. Enhancing connectivity between these habitats could significantly contribute to improving both the climate and genetic resilience of khulan populations.