Climate change and land use threaten global hotspots of phylogenetic endemism for trees

Across the globe, tree species are under high anthropogenic pressure. Risks of extinction are notably more severe for species with restricted ranges and distinct evolutionary histories. Here, we use a global dataset covering 41,835 species (65.1% of known tree species) to assess the spatial pattern of tree species' phylogenetic endemism, its macroecological drivers, and how future pressures may affect the conservation status of the identified hotspots. We found that low-to-mid latitudes host most endemism hotspots, with current climate being the strongest driver, and climatic stability across thousands to millions of years back in time as a major co-determinant. These hotspots are mostly located outside of protected areas and face relatively high land-use change and future climate change pressure. Our study highlights the risk from climate change for tree diversity and the necessity to strengthen conservation and restoration actions in global hotspots of phylogenetic endemism for trees to avoid major future losses of tree diversity. Species that are evolutionary distinct and have geographically narrow or isolated distributions may be in particular need of conservation. Here, the authors identify global patterns of tree phylogenetic endemism and their linkages with climate and land use, and estimate future trends.

Automated summary

This study examines the spatial pattern and drivers of tree phylogenetic endemism using a global dataset. The researchers found that most endemism hotspots are located in low-to-mid latitudes, with current climate being the main driver. However, these hotspots are also at risk from land-use change and future climate change.