Hyperdominance in the Amazonian Tree Flora

Hans ter Steege, Nigel C. A. Pitman, Daniel Sabatier, Christopher Baraloto, Rafael P. Salomão, Juan Ernesto Guevara, Oliver L. Phillips, Carolina V. Castilho, William E. Magnusson, Jean-François Molino, Abel Monteagudo, Percy Núñez Vargas, Juan Carlos Montero, Ted R. Feldpausch, Eurídice N. Honorio Coronado, Tim J. Killeen, Bonifacio Mostacedo, Rodolfo Vasquez, Rafael L. Assis, John Terborgh, Florian Wittmann, Ana Andrade, William F. Laurance, Susan G. W. Laurance, Beatriz S. Marimon, Ben-Hur Marimon, Ima Célia Guimarães Vieira, Iêda Leão Amaral, Roel Brienen, Hernán Castellanos, Dairon Cárdenas López, Joost F. Duivenvoorden, Hugo F. Mogollón, Francisca Dionízia de Almeida Matos, Nállarett Dávila, Roosevelt García-Villacorta, Pablo Roberto Stevenson Diaz, Flávia Costa, Thaise Emilio, Carolina Levis, Juliana Schietti, Priscila Souza, Alfonso Alonso, Francisco Dallmeier, Alvaro Javier Duque Montoya, Maria Teresa Fernandez Piedade, Alejandro Araujo-Murakami, Luzmila Arroyo, Rogerio Gribel, Paul V. A. Fine, Carlos A. Peres, Marisol Toledo, Gerardo A. Aymard C., Tim R. Baker, Carlos Cerón, Julien Engel, Terry W. Henkel, Paul Maas, Pascal Petronelli, Juliana Stropp, Charles Eugene Zartman, Doug Daly, David Neill, Marcos Silveira, Marcos Ríos Paredes, Jerome Chave, Diógenes de Andrade Lima Filho, Peter Møller Jørgensen, Alfredo Fuentes, Jochen Schöngart, Fernando Cornejo Valverde, Anthony Di Fiore, Eliana M. Jimenez, Maria Cristina Peñuela Mora, Juan Fernando Phillips, Gonzalo Rivas, Tinde R. van Andel, Patricio von Hildebrand, Bruce Hoffman, Eglée L. Zent, Yadvinder Malhi, Adriana Prieto, Agustín Rudas, Ademir R. Ruschell, Natalino Silva, Vincent Vos, Stanford Zent, Alexandre A. Oliveira, Angela Cano Schutz, Therany Gonzales, Marcelo Trindade Nascimento, Hirma Ramirez-Angulo, Rodrigo Sierra, Milton Tirado, María Natalia Umaña Medina, Geertje van der Heijden, César I. A. Vela, Emilio Vilanova Torre, Corine Vriesendorp, Ophelia Wang, Kenneth R. Young, Claudia Baider, Henrik Balslev, Cid Ferreira, Italo Mesones, Armando Torres-Lezama, Ligia Estela Urrego Giraldo, Roderick Zagt, Miguel N. Alexiades, Lionel Hernandez, Isau Huamantupa-Chuquimaco, William Milliken, Walter Palacios Cuenca, Daniela Pauletto, Elvis Valderrama Sandoval, Luis Valenzuela Gamarra, Kyle G. Dexter, Ken Feeley, Gabriela Lopez-Gonzalez, Miles R. Silman

The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community.