High exposure of global tree diversity to human pressure

Earth's tree diversity is crucial for biodiversity and ecosystem functions and services. Using species range estimates for 46,752 tree species, we find that an average of 50.2% of a tree species' range occurs in 110-km grid cells without any protected areas, with a total of 6,377 small-range tree species entirely unprotected, and that 83% of tree species experience nonnegligible human pressure across their range on average. Protecting additional areas selected to optimally cover multiple dimensions of tree diversity would strongly improve this situation. Our results highlight the need for strengthening efforts to protect tree diversity via increased coverage of protected areas through well-targeted conservation actions as well as integration of tree diversity into restoration efforts in human-dominated landscapes.