One sixth of Amazonian tree diversity is dependent on river floodplains
John Ethan Householder, Florian Wittmann, Jochen Schöngart, María Teresa Fernández Piedade, Wolfgang J. Junk, Edgardo M. Latrubesse, Adriano Costa Quaresma, Layon Oreste Demarchi, Guilherme Lobo, Daniel P. P. de Aguiar, Rafael L. Assis, Aline Lopes, Pia Parolin, Iêda Leão do Amaral, Luiz de Souza Coêlho, Francisca Dionízia de Almeida Matos, Diógenes de Andrade Lima Filho, Rafael P. Salomão, Carolina V. Castilho, Juan Ernesto Guevara-Andino, Marcelo de Jesus Veiga Carim, Oliver L. Phillips, Dairon Cárdenas López, William E. Magnusson, Daniel Sabatier, Juan David Cardenas Revilla, Jean‐François Molino, Mariana Victória Irume, Maria Pires Martins, José Renan da Silva Guimarães, José Ferreira Ramos, Domingos de Jesus Rodrigues, Olaf Bánki, Carlos A. Peres, Nigel C. A. Pitman, Joseph E. Hawes, Everton José Almeida, Luciane Ferreira Barbosa, Larissa Cavalheiro, Márcia Cléia Vilela dos Santos, Bruno Garcia Luize, Evlyn Márcia Moraes de Leão Novo, Percy Núñez Vargas, Thiago Sanna Freire Silva, Eduardo Martins Venticinque, Ângelo Gilberto Manzatto, Neidiane Farias Costa Reis, John Terborgh, Katia Regina Casula, Flávia R. C. Costa, Eurídice N. Honorio Coronado, Abel Monteagudo Mendoza, Juan Carlos Montero, Ted R. Feldpausch, Gerardo A. Aymard C., Christopher Baraloto, Nicolás Castaño Arboleda, Julien Engel, Pascal Pétronelli, Charles E. Zartman, Timothy J. Killeen, Lorena Maniguaje Rincón, Beatriz Schwantes Marimon, Ben Hur Marimon, Juliana Schietti, Thaiane R. Sousa, Rodolfo Vásquez, Bonifacio Mostacedo, Dário Dantas do Amaral, Hernán Castellanos, Marcelo Brilhante de Medeiros, Marcelo Fragomeni Simon, Ana Andrade, José Luís Camargo, William F. Laurance, Susan G. W. Laurance, Emanuelle de Sousa Farias, Maria Aparecida Lopes, José Leonardo Lima Magalhães, Henrique Eduardo Mendonça Nascimento, Helder Lima de Queiroz, Roel Brienen, Pablo R. Stevenson, Alejandro Araujo‐Murakami, Timothy R. Baker, Bruno Barçante Ladvocat Cintra, Yuri Oliveira Feitosa, Hugo F. Mogollón, Janaína Costa Noronha, F. R. Barbosa, Rainiellen de Sá Carpanedo, Joost F. Duivenvoorden, Miles R. Silman, Leandro Valle Ferreira, Carolina Levis, José Rafael Lozada, James A. Comiskey, Frederick C. Draper, José Júlio de Toledo, Gabriel Damasco
Abstract
Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.