GlobalTreeSearch: The first complete global database of tree species and country distributions

This article presents, for the first time, an overview of all known tree species by scientific name and country level distribution, and describes an online database-GlobalTreeSearch-that provides access to this information. Based on our comprehensive analysis of published data sources and expert input, the number of tree species currently known to science is 60,065, representing 20% of all angiosperm and gymnosperm plant species. Nearly half of all tree species (45%) are found in just 10 families, with the 3 most tree-rich families being Leguminosae, Rubiaceae, and Myrtaceae. Geographically, Brazil, Colombia, and Indonesia are the countries with the most tree species. The countries with the most country-endemic tree species reflect broader plant diversity trends (Brazil, Australia, China) or islands where isolation has resulted in speciation (Madagascar, Papua New Guinea, Indonesia). Nearly 58% of all tree species are single-country endemics. Our intention is for GlobalTreeSearch to be used as a tool for monitoring and managing tree species diversity, forests, and carbon stocks on a global, regional, and/or national level. It will also be used as the basis of the Global Tree Assessment, which aims to assess the conservation status of all of the world's tree species by 2020.