Climate change threatens the conservation of one of the world's most endangered transboundary tree species: Magnolia grandis

The Sino-Vietnamese border region is known for having unique and high levels of biodiversity. Global climate change is expected to alter the region's climate and related changes in habitats and ecosystems will result in shifts in species' distributions and increase the likelihood of local and global extinctions. Ecological Niche Models (ENMs) are widely used to predict the magnitude of potential species distribution shifts in response to climate change and inform conservation planning. Here, we present climate -based ENM projections of future climatically suitable habitat for the Daguo Mulian tree ( Magnolia grandis ), a critically endangered species of high ecological and cultural value in the Sino-Vietnamese border region. Projections of modeled climatically suitable habitat for M. grandis, both for the 2050s and 2070s, suggest significant habitat loss within conservation areas, and a defining shift in the location of suitable habitat. Future projections are conservative and do not account for dispersal limitations or species interactions or other factors, and thus may overestimate potential shifts and underestimate losses. Our results suggest that current conservation management efforts for M. grandis , which include community forest conservation monitoring combined with nursery cultivation efforts, can continue to have success if implemented in an adaptive management framework with long-term research and monitoring to inform forward -thinking decisions with future climatic suitability in mind. The results also underline how endangered species' distributions may shift across borders as they track suitable climates, emphasizing that nations will need to cooperate to effectively manage threatened species and habitats and prevent extinctions.