Large-scale changes in the distribution of suitable habitat of the endangered subtropical canopy tree species Vatica guangxiensis under climate change

Protecting rare and endangered species from habitat loss caused by climate and land use changes is crucial for stopping unprecedented biodiversity loss. Data on species’ future range shifts is crucial in protected area management planning to establish proper refuges. This study focused on identifying the suitable habitat, vulnerabilities, and conservation gaps of Vatica guangxiensis—a canopy tree species endemic to the subtropical forests of southwest China and listed as Endangered in the IUCN Red List— through Maxent species distribution modeling using current and future climate data. Results showed that the predicted suitable habitats for V. guangxiensis under current climate were more extensive than its known range, encompassing parts of China, northern Laos, northern Vietnam, and eastern Myanmar. They are most likely to be in wetter regions with acidic soils. However, these habitats were predicted to decrease by 90% and shift to lower latitudes and higher elevations by 2081–2100 due to climate change, which leads to habitat loss for five out of twelve current wild populations, as well as severe fragmentation and reduced protected area coverage. Our findings demonstrate the potential for new field discoveries of V. guangxiensis based on its predicted distribution under current climate, but also show the vulnerability of its habitats under future climate change. We present a dire outlook for V. guangxiensis and highlight the need for field discovery of new populations and the establishment of ex situ populations that are explicitly guided by suitable habitat predictions. Furthermore, this study can contribute to the expansion of climate-informed protected areas in the Indochina region, to support the flagship ‘30 × 30’ target for protected areas under the Kunming-Montreal Global Biodiversity Framework. Lastly, our findings elucidate the importance of transboundary conservation efforts, such as the Lancang-Mekong Cooperation Five-Year Action Plan, in preserving biodiversity and achieving global conservation goals.