Canopy functional trait variation across Earth’s tropical forests

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 properties 3. This situation arises, in part, from a lack of understanding about how and why the functional properties of tropical forest canopies vary geographically 4. Here, by combining feld-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.

Additional Co-authors; Jesús Aguirre-Gutiérrez1,2 ✉, Sami W. Rifai3, Xiongjie Deng1 , Hans ter Steege4,5, Eleanor Thomson1, Jose Javier Corral-Rivas6 , Aretha Franklin Guimaraes7, Sandra Muller8, Joice Klipel8,105, Sophie Fauset9, Angelica F. Resende10,11, Göran Wallin1,12, Carlos A. Joly13,14, Katharine Abernethy11,15, Stephen Adu-Bredu16,17, Celice Alexandre Silva18, Edmar Almeida de Oliveira19, Danilo R. A. Almeida10, Esteban Alvarez-Davila20, Gregory P. Asner21, Timothy R. Baker22, Maíra Benchimol23, Lisa Patrick Bentley24, Erika Berenguer1,25, Lilian Blanc26, Damien Bonal27, Kauane Bordin28, Robson Borges de Lima29, Sabine Both30, Jaime Cabezas Duarte31,32, Domingos Cardoso33,34, Haroldo C. de Lima34, Larissa Cavalheiro35, Lucas A. Cernusak36, Nayane Cristina C. dos Santos Prestes19, Antonio Carlos da Silva Zanzini37, Ricardo José da Silva18, Robson dos Santos Alves da Silva18, Mariana de Andrade Iguatemy34,38, Tony César De Sousa Oliveira39,40, Benjamin Dechant41,42, Géraldine Derroire26,43, Kyle G. Dexter44,45,46, Domingos J. Rodrigues35, Mário Espírito-Santo47, Letícia Fernandes Silva48,49, Tomas Ferreira Domingues50,51, Joice Ferreira52, Marcelo Fragomeni Simon53, Cécile A. J. Girardin1 , Bruno Hérault26, Kathryn J. Jeffery11, Sreejith Kalpuzha Ashtamoorthy54, Arunkumar Kavidapadinjattathil Sivadasan54, Bente Klitgaard55, William F. Laurance36, Maurício Lima Dan56, William E. Magnusson7, Eduardo Malta Campos-Filho57, Rubens Manoel dos Santos58, Angelo Gilberto Manzatto59, Marcos Silveira60, Ben Hur Marimon-Junior61, Roberta E. Martin21, Daniel Luis Mascia Vieira53, Thiago Metzker62,63, William Milliken64, Peter Moonlight65, Marina Maria Moraes de Seixas52, Paulo S. Morandi66, Robert Muscarella67, María Guadalupe Nava-Miranda68,69, Brigitte Nyirambangutse70,71, Jhonathan Oliveira Silva72, Imma Oliveras Menor1,73, Pablo José Francisco Pena Rodrigues34, Cinthia Pereira de Oliveira29, Lucas Pereira Zanzini74, Carlos A. Peres75, Vignesh Punjayil54, Carlos A. Quesada76, Maxime Réjou-Méchain73, Terhi Riutta1,77, Gonzalo Rivas-Torres78, Clarissa Rosa7, Norma Salinas79, Rodrigo Scarton Bergamin80,81, Beatriz Schwantes Marimon61, Alexander Shenkin82, Priscyla Maria Silva Rodrigues72, Axa Emanuelle Simões Figueiredo83, Queila Souza Garcia84, Tereza Spósito62, Danielle Storck-Tonon85, Martin J. P. Sullivan86, Martin Svátek87, Wagner Tadeu Vieira Santiago88, Yit Arn Teh89, Prasad Theruvil Parambil Sivan54, Marcelo Trindade Nascimento90, Elmar Veenendaal91, Irie Casimir Zo-Bi92, Marie Ruth Dago92, Soulemane Traoré92,93, Marco Patacca94, Vincyane Badouard43,73,92, Samuel de Padua Chaves e Carvalho95, Lee J. T. White11,15, Huanyuan Zhang-Zheng1,2, Etienne Zibera12,96, Joeri Alexander Zwerts97, David F. R. P. Burslem98, Miles Silman99,100, Jérôme Chave101, Brian J. Enquist102,103, Jos Barlow25, Oliver L. Phillips22, David A. Coomes104& Yadvinder Malhi1,2