The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.30 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.66 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization.
We thank P. Peterkins for her support throughout the study. We also thank Plant for the Planet for initial discussions and for collaboration during the study. The main project was funded by grants to T.W.C. from the Yale Climate and Energy Institute and the British Ecological Society. We acknowledge various sources for tree density measurements and estimates: the Canadian National Forest Inventory (https://nfi.nfis.org/index.php), the US Department of Agriculture Forest Service for their National Forest Inventory and Analysis (http://fia.fs.fed.us/), the Taiwan Forestry Bureau (which provided the National Vegetation Database of Taiwan), the DFG (German Research Foundation), BMBF (Federal Ministry of Education and Science of Germany), the Floristic and Forest Inventory of Santa Catarina (IFFSC), the National Vegetation Database of South Africa, and the Chilean research grants FONDECYT no. 1151495. For Europe NFI plot data were brought together with input from J. Rondeux and M. Waterinckx, Belgium, T. Bélouard, France, H. Polley, Germany, W. Daamen and H. Schoonderwoerd, Netherlands, S. Tomter, Norway, J. Villanueva and A. Trasobares, Spain, G. Kempe, Sweden. New Zealand Natural Forest plot data were collected by the LUCAS programme for the Ministry for the Environment (New Zealand) and sourced from the National Vegetation Survey Databank (New Zealand) (http://nvs.landcareresearch.co.nz). We also acknowledge the BCI forest dynamics research project, which was funded by National Science Foundation grants to S. P. Hubbell, support from the Center for Tropical Forest Science, the Smithsonian Tropical Research Institute, the John D. and Catherine T. MacArthur Foundation, the Mellon Foundation, the Small World Institute Fund, numerous private individuals, the Ucross High Plains Stewardship Initiative, and the hard work of hundreds of people from 51 countries over the past two decades. The plot project is part of the Center for Tropical Forest Science, a global network of large-scale demographic tree plots.
Extended data figures
Summary Table showing the number of plot estimates and total tree numbers (with 95% confidence interval) at the biome and global scale.
This table shows the number of trees and tree densities for countries of the world, as estimated using 2 independent approaches (biome and ecoregion-level models) and the database of Global Administrative Areas, version 2.7 (http://gadm.org/).