Tropical forest canopies are the biosphere's most concentrated atmospheric interface for carbon, water and energy1,2. However, in most Earth System Models, the diverse and heterogeneous tropical forest biome is represented as a largely uniform ecosystem with either a singular or a small number of fixed canopy ecophysiological properties3. This situation arises, in part, from a lack of understanding about how and why the functional properties of tropical forest canopies vary geographically4. Here, by combining field-collected data from more than 1,800 vegetation plots and tree traits with satellite remote-sensing, terrain, climate and soil data, we predict variation across 13 morphological, structural and chemical functional traits of trees, and use this to compute and map the functional diversity of tropical forests. Our findings reveal that the tropical Americas, Africa and Asia tend to occupy different portions of the total functional trait space available across tropical forests. Tropical American forests are predicted to have 40% greater functional richness than tropical African and Asian forests. Meanwhile, African forests have the highest functional divergence-32% and 7% higher than that of tropical American and Asian forests, respectively. An uncertainty analysis highlights priority regions for further data collection, which would refine and improve these maps. Our predictions represent a ground-based and remotely enabled global analysis of how and why the functional traits of tropical forest canopies vary across space.

AMAP Université de Montpellier IRD CNRS CIRAD INRAE Montpellier France

Biological and Environmental Sciences University of Stirling Stirling UK

Birmingham Institute of Forest Research University of Birmingham Birmingham UK

Botany School of Natural Sciences Trinity College Dublin Dublin Ireland

Brazilian Platform on Biodiversity and Ecosystem Services Campinas Brazil

Center for Energy Environment and Sustainability Wake Forest University Winston Salem NC USA

Center for Global Discovery and Conservation Science Arizona State University Tempe AZ USA

Centre de Recherche Biodiversité Environnement CNRS UPS IRD Université de Toulouse INPT Toulouse France

Centro de Ciências Biológicas e da Natureza Universidade Federal do Acre Rio Branco Brazil

Centro de Pesquisa Desenvolvimento e Inovação Sul Instituto Capixaba de Pesquisa Assistência Técnica e Extensão Rural Cachoeiro de Itapemirim Brazil

CESAM Centro de Estudos do Ambiente e do Mar Departamento de Biologia Pesquisador Colaborador Universidade de Aveiro Aveiro Portugal

Cirad UMR EcoFoG Campus Agronomique Kourou French Guiana

Colegiado de Ecologia Universidade Federal do Vale do São Francisco Senhor do Bonfim Brazil

Colegio de Ciencias y Humanidades Universidad Juárez del Estado de Durango Durango Mexico

College of Science and Engineering James Cook University Cairns Queensland Australia

Conservation Research Institute and Department of Plant Sciences University of Cambridge Cambridge UK

Coordenação de Biodiversidade Instituto Nacional de Pesquisas da Amazônia Manaus Brazil

Coordenação de Dinâmica Ambiental Instituto Nacional de Pesquisas da Amazônia Manaus Brazil

CSIR Forestry Research Institute of Ghana Kumasi Ghana

Departamento de Biologia Geral Universidade Estadual de Montes Claros Montes Claros Brazil

Departamento de Biologia Universidade Federal de Rondônia Porto Velho Brazil

Departamento de Biologia Vegetal Instituto de Biologia Universidade Estadual de Campinas Campinas Brazil

Departamento de Engenharia Florestal Universidade de Brasília Brasília Brazil

Departamento de Engenharia Florestal Universidade do Estado de Mato Grosso Caceres Brazil

Departamento de Engenharia Florestal Universidade Federal de Lavras Lavras Brazil

Department for Accelerated Taxonomy Royal Botanic Gardens Kew Richmond UK

Department of Biological and Environmental Sciences University of Gothenburg Gothenburg Sweden

Department of Biology Sonoma State University Rohnert Park CA USA

Department of Biology Wake Forest University Winston Salem NC USA

Department of Ecology and Evolutionary Biology University of Arizona Tucson AZ USA

Department of Ecology Universidade Federal do Rio Grande do Sul Porto Alegre Brazil

Department of Forest Botany Dendrology and Geobiocoenology Faculty of Forestry and Wood Technology Mendel University in Brno Brno Czech Republic

Department of Forest Sciences Luiz de Queiroz College of Agriculture University of São Paulo Piracicaba Brazil

Department of Geography University of Exeter Exeter UK

Department of Life Sciences and Systems Biology University of Turin Turin Italy

Department of Natural Resources Management CSIR College of Science and Technology Kumasi Ghana

Department of Natural Sciences Manchester Metropolitan University Manchester UK

Embrapa Amazônia Oriental Belém Brazil

Embrapa Recursos Genéticos e Biotecnologia Brasília Brazil

Environmental and Rural Science University of New England Armidale New South Wales Australia

Environmental Change Institute School of Geography and the Environment University of Oxford Oxford UK

Escuela de Ciencias Agrícolas Pecuarias y Ambientales ECAPMA Universidad Nacional Abierta y a Distancia Bogota Colombia

Escuela Politécnica Superior de Ingeniería Universidad de Santiago de Compostela Campus Terra Lugo España

Estación de Biodiversidad Tiputini Colegio de Ciencias Biológicas y Ambientales Universidad San Francisco de Quito Quito Ecuador

Faculdade de Filosofia Ciências e Letras de Ribeirão Preto Ribeirão Preto Brazil

Facultad de Ciencias Forestales y Ambientales Universidad Juárez del Estado de Durango Durango Mexico

Faculty of Communication and Environment Hochschule Rhein Waal Kamp Lintfort Germany

Federal Rural University of Rio de Janeiro Seropedica Brazil

Forest Ecology and Forest Management Group Wageningen University and Research Wageningen The Netherlands

Forest Ecology Department KSCSTE Kerala Forest Research Institute Kerala India

Forêts et Sociétés Université de Montpellier CIRAD Montpellier France

German Centre for Integrative Biodiversity Research Halle Jena Leipzig Leipzig Germany

Global Green Growth Institute Rwanda Program Kigali Rwanda

IBAM Instituto Bem Ambiental Belo Horizonte Brazil

INRAE Université de Lorraine AgroParisTech UMR Silva Nancy France

Institut de Recherche en Écologie Tropicale Libreville Gabon

Institute for Nature Earth and Energy Pontificia Universidad Católica del Perú Lima Peru

Institute of Biogeosciences IBG2 Plant Sciences Forschungszentrum Jülich GmbH Jülich Germany

Institute of Ecology Leuphana University of Lüneburg Lüneburg Germany

Instituto de Biologia Universidade Federal da Bahia Salvador Brazil

Instituto de Ciências Biológicas Departamento de Botânica Universidade Federal de Minas Gerais Belo Horizonte Brazil

Instituto de Pesquisas Jardim Botânico do Rio de Janeiro Rio de Janeiro Brazil

Instituto Internacional para Sustentabilidade Rio de Janeiro Brazil

Instituto Socioambiental São Paulo Brazil

Jardín Botánico de Bogotá Bogotá Colombia

Laboratório de Ciências Ambientais CBB Universidade Estadual do Norte Fluminense Darcy Ribeiro Campos dos Goytacazes Brazil

Laboratório de Ecologia Aplicada à Conservacão Departamento de Ciências Biológicas Universidade Estadual de Santa Cruz Ilhéus Brazil

Laboratório de Ecologia Vegetal Universidade do Estado de Mato Grosso Nova Xavantina Brazil

Laboratório de Fitogeografia e Ecologia Evolutiva Departamento de Ciências Florestais Universidade Federal de Lavras Lavras Brazil

Laboratório de Manejo Florestal Universidade do Estado do Amapá Macapá Brazil

Lancaster Environment Centre Lancaster University Lancaster UK

Leipzig University Leipzig Germany

Leverhulme Centre for Nature Recovery University of Oxford Oxford UK

Ministry of Water and Forests Abidjan Côte d'Ivoire

Myr Projetos Sustentáveis Belo Horizonte Brazil

Naturalis Biodiversity Center Leiden The Netherlands

Plant Ecology and Evolution Department of Ecology and Genetics Uppsala University Uppsala Sweden

Plant Ecology and Nature Conservation Group Wageningen University and Research Wageningen The Netherlands

Plant Ecology Lab Ecology Department Universidade Federal do Rio Grande do Sul Porto Alegre Brazil

PPG Ecology and Conservation Universidade do Estado de Mato Grosso Nova Xavantina Brazil

Programa de Pós graduação em Ambiente e Sistemas de Produção Agrícola Universidade do Estado de Mato Grosso Tangará da Serra Brazil

Programa de Pós graduação em Ecologia e Conservação Universidade do Estado de Mato Grosso Nova Xavantina Brazil

Quantitative Biodiversity Dynamics Utrecht University Utrecht The Netherlands

Royal Botanic Garden Edinburgh Edinburgh UK

Royal Botanic Gardens Kew Richmond UK

School of Biological Sciences University of Aberdeen Aberdeen UK

School of Biological Sciences University of Adelaide Adelaide South Australia Australia

School of Environmental Sciences University of East Anglia Norwich UK

School of Forestry and Biodiversity and Biological Sciences College of Agriculture Animal Sciences and Veterinary Medicine University of Rwanda Musanze Rwanda

School of Geography Earth and Environmental Sciences University of Birmingham Birmingham UK

School of Geography Earth and Environmental Sciences University of Plymouth Plymouth UK

School of Geography University of Leeds Leeds UK

School of GeoSciences University of Edinburgh Edinburgh UK

School of Informatics Computing and Cyber Systems Northern Arizona University Flagstaff AZ USA

School of Natural and Environmental Sciences Newcastle University Newcastle upon Tyne UK

The Santa Fe Institute Santa Fe USA

UMRI SAPT Institut National Polytechnique Félix Houphouët Boigny Yamoussoukro Côte d'Ivoire

Universidad de los Andes Bogotá Colombia

Universidade de São Paulo São Paulo Brazil

Universidade do Estado de Mato Grosso Tangará da Serra Brazil

Universidade Federal de Mato Grosso Sinop Brazil

Universidade Federal do Acre Rio Branco Brazil

Universidade Paulista Polo Rio Branco Brazil

University of Rwanda Kigali Rwanda

Utrecht University Utrecht The Netherlands

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Canopy functional trait variation across Earth's tropical forests