Pauline Depoortere, David Bauman, Adeline Fayolle, Oliver Phillips, Lalasia Bialic-Murphy, Constantin M Zohner, Arthur Vander Linden, Antoine Plumacker, Hugo de Lame, Jingjing Liang, Peter B Reich, Javier G P Gamarra, Giorgio Alberti, Bruno Hérault, Nicolas Picard, Sergio de-Miguel, Gert-Jan Nabuurs, Thomas W Crowther, Alain Paquette, Hans Pretzsch, Susan K Wiser, Mo Zhou, Han Y H Chen, Hans Verbeeck, Charles De Cannière, Martin J P Sullivan, Lourens Poorter, Quentin Ponette, Marijn Bauters, Vincent Deblauwe, Gunnar Keppel, Francis Q Brearley, Irié Casimir Zo-Bi, Tiodionwa Abdoulaye Ouattara, Michael J Lawes, Frans Bongers, Jorge A Meave, Mark Schulze, Michael Lyonga Ngoh, Hans Ter Steege, Jürgen Homeier, Akomian Fortuné Azihou, Liam Trethowan, J W Ferry Slik, Géraldine Derroire, Damien Bonal, William F Laurance, Andreas Hemp, Agustinus Murdjoko, Jesús Aguirre-Gutiérrez, Endang Kintamani, Lee White, Simon L Lewis, Andrew Hector, Christian Amani, Ana Andrade, Albert Angbonga, Luiz Aragão, Ayushi Kurian, Félix Allah Barem, Angelica M Almeyda Zambrano, Esteban Alvarez-Davila, Patricia Alvarez-Loayza, Elisée Amstrong, Alejandro Araujo-Murakami, Luzmila Arroyo, Timothy R Baker, Ousmane Bako, Olaf Bánki, Christopher Baraloto, Nicolas Barbier, Jorcely Gonçalves Barroso, Patrick Bassama, Hans Beeckman, Nithanel Mikael Hendrik Benu, Hervé Bihiya, Philippe Birnbaum, Robert Bitariho, Pascal Boeckx, Kelly Boekee, Jan Bogaert, Katrin Böhning-Gease, Faustin Boyemba, Hilândia Brandão da Cunha, Roel Brienen, Jaime Briseño-Reyes, Eben N Broadbent, Jose Luis Camargo, Benoît Cassart, Roberto Cazzolla Gatti, Jérôme Chave, George Chuyong, David B Clark, Connie Clark, Alessio Collalti, Murray Collins, Fernando Cornejo Valverde, Jose Javier Corral-Rivas, Pierre Couteron, Aida Cuni-Sanchez, Lôla da Costa, Jose Daniel Soto, Ashaq Ahmad Dar, Javid Ahmad Dar, Gilles Dauby, Thales de Haulleville, Anthony Di Fiore, John Diisi, Marie-Noel Djuikouo K, Jiri Dolezal, Narcisse Dongmo, Jean-Louis Doucet, Vincent Droissart, Julien Engel, Nestor Laurier Engone Obiang, Santiago Espinosa, Teresa Eyre, Sophie Fauset, Ted R Feldpausch, Markus Fischer, Krisna Gajapersad, Deden Girmansyah, Emanuel Gloor, Ieda Gomes do Amaral, Christelle Flore Gonmadje, Elisa Grieco, James Grogan, Richard Habonayo, David J Harris, Eurídice Honorio Coronado, Isau Huamantupa-Chuquimaco, Wannes Hubau, Patrick A Jansen, Kathryn J Jeffery, Blaise Jumbam, Naveen Babu Kanda, Narcisse Kamdem, Emmanuel Kasongo Yakusu, John Katembo, Charles Kayijamahe, Elizabeth Kearsley, David Kenfack, Mohammed Latif Khan, Timothy Killeen, Subashree Kothandaraman, Ronald Kougue, Amit Kumar, Relawan Kuswandi, Nicolas Labrière, David Lasso, Susan Laurance, Miguel Leal, Hugo Leblanc, Moses Libalah, Janvier Lisingo, Yadvinder Malhi, Beatriz S Marimon, Ben Hur Marimon Junior, Andrew R Marshall, Emanuel H Martin, Olivier Martin-Ducup, Michel M Mbasi, Faustin Mbayu, Casimiro Mendoza, Irina Mendoza Polo, Gislain Mofack, Abel Monteagudo-Mendoza, Arafat Mtui, S Muthuramkumar, Ayyappan Narayanan, María Guadalupe Nava-Miranda, David Neill, Victor John Neldner, Eric Ngansop Tchatchouang, Fernandez Ngoula, Michael R Ngugi, Moses Nsanyi Sainge, Percy Núñez Vargas, Edgar Ortiz-Malavassi, Nadir Pallqui Camacho, Vivek Pandi, Germaine Alexander Parada Gutierrez, Guido Pardo, Narayanaswamy Parthasarathy, Raphael Pelissier, Sebastian Pfautsch, Bryan C Pijanowski, Daniel Piotto, John Pipoly, Nigel Pitman, Pierre Ploton, John R Poulsen, B R Ramesh, Freddy Ramirez Arevalo, Hirma Ramírez-Angulo, L Rasingam, Maxime Réjou-Méchain, Zorayda Restrepo Correa, Wilson Roberto Spironello, Cintia Rodrigues de Souza, Lily O Rodriguez, Samir Rolim, Anand Roopsind, Francesco Rovero, Le Bienfaiteur Sagang, Purabi Saikia, Antonello Salis, Benoit Patrick Salla, Javier Eduardo Silva Espejo, Marcos Silveira, Murielle Simo-Droissart, Nelly Sirri, Bonaventure Sonké, Somaiah Sundarapandian, Michael Swaine, Ben Swanepoel, Hermann Taedoumg, Imma Tcheferi, John Terborgh, Duncan Thomas, Raquel Thomas, John Tshibamba Mukendi, Peter M Umunay, Renato Valencia, Luis Valenzuela Gamarra, Leandro Valle Ferreira, Geertje van der Heijden, Rodolfo Vasquez Martinez, José Daniel Vega-Nieva, Emilio Vilanova, Braulio Vilchez Alvarado, Barbara Vinceti, Jason Vleminckx, Klaus von Gadow, Vincent Antoine Vos, Eric Wasingya, James Watson, Verginia Wortel, Roderick Zagt, Donatien Zébazé, ForestPlots.net, GFBI, Jean-François Bastin
Old-growth tropical forests store vast amounts of carbon in their aboveground biomass (AGB), yet the relative roles of abiotic factors such as climate, soil, and topography in governing its spatial distribution remain poorly understood. In particular, the degree to which climate acts on AGB through forest structure is still poorly quantified at the pantropical scale. Using a pantropical dataset of more than 2,000 old-growth forest plots and a structure-explicit framework, we assess how climate influences AGB through its effects on four structural attributes: basal area, mean diameter, stem density, and basal area-weighted wood density. We find that climate shapes AGB primarily through its effects on forest structure. However, structural attributes respond to climate in opposite directions, so climate's net effect on AGB largely cancels out, and no clear climate-AGB relationship emerges across tropical regions. Moreover, only wood density responds consistently, decreasing with annual precipitation and increasing with precipitation seasonality, whereas all other attributes respond to climate differently from one region to another. This geographical variation further obscures any global climatic signal on AGB and points to the role of biogeographic history in shaping forest structure. Our findings highlight the central role of the climate-structure nexus in explaining AGB variation, and call for structure-explicit models to improve carbon stock predictions and inform climate adaptation strategies.