Water table depth modulates productivity and biomass across Amazonian forests

Sousa, Thaiane R. and Schietti, Juliana and Ribeiro, Igor O. and Emílio, Thaise and Fernández, Rafael Herrera and Steege, Hans and Castilho, Carolina V. and Esquivel‐Muelbert, Adriane and Baker, Timothy and Pontes‐Lopes, Aline and Silva, Camila V. J. and Silveira, Juliana M. and Derroire, Géraldine and Castro, Wendeson and Mendoza, Abel Monteagudo and Ruschel, Ademir and Prieto, Adriana and Lima, Adriano José Nogueira and Rudas, Agustín and Araujo‐Murakami, Alejandro and Gutierrez, Alexander Parada and Andrade, Ana and Roopsind, Anand and Manzatto, Angelo Gilberto and Di Fiore, Anthony and Torres‐Lezama, Armando and Dourdain, Aurélie and Marimon, Beatriz and Marimon, Ben Hur and Burban, Benoit and Ulft, Bert and Herault, Bruno and Quesada, Carlos and Mendoza, Casimiro and Stahl, Clement and Bonal, Damien and Galbraith, David and Neill, David and Oliveira, Edmar A. and Hase, Eduardo and Jimenez‐Rojas, Eliana and Vilanova, Emilio and Arets, Eric and Berenguer, Erika and Alvarez‐Davila, Esteban and Honorio Coronado, Eurídice N. and Almeida, Everton and Coelho, Fernanda and Valverde, Fernando Cornejo and Elias, Fernando and Brown, Foster and Bongers, Frans and Arevalo, Freddy Ramirez and Lopez‐Gonzalez, Gabriela and Heijden, Geertje and Aymard C., Gerardo A. and Llampazo, Gerardo Flores and Pardo, Guido and Ramírez‐Angulo, Hirma and Amaral, Iêda Leão and Vieira, Ima Célia Guimarães and Huamantupa‐Chuquimaco, Isau and Comiskey, James A. and Singh, James and Espejo, Javier Silva and Aguila‐Pasquel, Jhon and Zwerts, Joeri Alexander and Talbot, Joey and Terborgh, John and Ferreira, Joice and Barroso, Jorcely G. and Barlow, Jos and Camargo, José Luís and Stropp, Juliana and Peacock, Julie and Serrano, Julio and Melgaço, Karina and Ferreira, Leandro V. and Blanc, Lilian and Poorter, Lourens and Gamarra, Luis Valenzuela and Aragão, Luiz and Arroyo, Luzmila and Silveira, Marcos and Peñuela‐Mora, Maria Cristina and Vargas, Mario Percy Núñez and Toledo, Marisol and Disney, Mat and Réjou‐Méchain, Maxime and Baisie, Michel and Kalamandeen, Michelle and Camacho, Nadir Pallqui and Cardozo, Nállarett Dávila and Silva, Natalino and Pitman, Nigel and Higuchi, Niro and Banki, Olaf and Loayza, Patricia Alvarez and Graça, Paulo M. L. A. and Morandi, Paulo S. and Meer, Peter J. and Hout, Peter and Naisso, Pétrus and Camargo, Plínio Barbosa and Salomão, Rafael and Thomas, Raquel and Boot, Rene and Umetsu, Ricardo Keichi and Costa Silva, Richarlly and Burnham, Robyn and Zagt, Roderick and Martinez, Rodolfo Vasquez and Brienen, Roel and Ribeiro, Sabina Cerruto and Lewis, Simon L. and Vieira, Simone Aparecida and Almeida Reis, Simone Matias and Fauset, Sophie and Laurance, Susan and Feldpausch, Ted and Erwin, Terry and Killeen, Timothy and Wortel, Verginia and Moscoso, Victor Chama and Vos, Vincent and Huasco, Walter Huaraca and Laurance, William and Malhi, Yadvinder and Magnusson, William E. and Phillips, Oliver L. and Costa, Flávia R. C. and Grytnes, John‐Arvid (2022) Water table depth modulates productivity and biomass across Amazonian forests. Global Ecology and Biogeography, 31 (8). pp. 1571-1588. ISSN 1466-822X

Abstract

AbstractAimWater availability is the major driver of tropical forest structure and dynamics. Most research has focused on the impacts of climatic water availability, whereas remarkably little is known about the influence of water table depth and excess soil water on forest processes. Nevertheless, given that plants take up water from the soil, the impacts of climatic water supply on plants are likely to be modulated by soil water conditions.LocationLowland Amazonian forests.Time period1971–2019.MethodsWe used 344 long‐term inventory plots distributed across Amazonia to analyse the effects of long‐term climatic and edaphic water supply on forest functioning. We modelled forest structure and dynamics as a function of climatic, soil‐water and edaphic properties.ResultsWater supplied by both precipitation and groundwater affects forest structure and dynamics, but in different ways. Forests with a shallow water table (depth <5 m) had 18% less above‐ground woody productivity and 23% less biomass stock than forests with a deep water table. Forests in drier climates (maximum cumulative water deficit < −160 mm) had 21% less productivity and 24% less biomass than those in wetter climates. Productivity was affected by the interaction between climatic water deficit and water table depth. On average, in drier climates the forests with a shallow water table had lower productivity than those with a deep water table, with this difference decreasing within wet climates, where lower productivity was confined to a very shallow water table.Main conclusionsWe show that the two extremes of water availability (excess and deficit) both reduce productivity in Amazon upland (terra‐firme) forests. Biomass and productivity across Amazonia respond not simply to regional climate, but rather to its interaction with water table conditions, exhibiting high local differentiation. Our study disentangles the relative contribution of those factors, helping to improve understanding of the functioning of tropical ecosystems and how they are likely to respond to climate change.