Amazon tree dominance across forest strata

Draper, F.C. and Costa, F.R.C. and Arellano, G. and Phillips, O.L. and Duque, A. and Macía, M.J. and ter Steege, H. and Asner, G.P. and Berenguer, E. and Schietti, J. and Socolar, J.B. and de Souza, F.C. and Dexter, K.G. and Jørgensen, P.M. and Tello, J.S. and Magnusson, W.E. and Baker, T.R. and Castilho, C.V. and Monteagudo-Mendoza, A. and Fine, P.V.A. and Ruokolainen, K. and Coronado, E.N.H. and Aymard, G. and Dávila, N. and Sáenz, M.S. and Paredes, M.A.R. and Engel, J. and Fortunel, C. and Paine, C.E.T. and Goret, J.-Y. and Dourdain, A. and Petronelli, P. and Allie, E. and Andino, J.E.G. and Brienen, R.J.W. and Pérez, L.C. and Manzatto, Â.G. and Zambrana, N.Y.P. and Molino, J.-F. and Sabatier, D. and Chave, J. and Fauset, S. and Villacorta, R.G. and Réjou-Méchain, M. and Berry, P.E. and Melgaço, K. and Feldpausch, T.R. and Sandoval, E.V. and Martinez, R.V. and Mesones, I. and Junqueira, A.B. and Roucoux, K.H. and de Toledo, J.J. and Andrade, A.C. and Camargo, J.L. and del Aguila Pasquel, J. and Santana, F.D. and Laurance, W.F. and Laurance, S.G. and Lovejoy, T.E. and Comiskey, J.A. and Galbraith, D.R. and Kalamandeen, M. and Aguilar, G.E.N. and Arenas, J.V. and Guerra, C.A.A. and Flores, M. and Llampazo, G.F. and Montenegro, L.A.T. and Gomez, R.Z. and Pansonato, M.P. and Moscoso, V.C. and Vleminckx, J. and Barrantes, O.J.V. and Duivenvoorden, J.F. and de Sousa, S.A. and Arroyo, L. and Perdiz, R.O. and Cravo, J.S. and Marimon, B.S. and Junior, B.H.M. and Carvalho, F.A. and Damasco, G. and Disney, M. and Vital, M.S. and Diaz, P.R.S. and Vicentini, A. and Nascimento, H. and Higuchi, N. and Van Andel, T. and Malhi, Y. and Ribeiro, S.C. and Terborgh, J.W. and Thomas, R.S. and Dallmeier, F. and Prieto, A. and Hilário, R.R. and Salomão, R.P. and Silva, R.C. and Casas, L.F. and Vieira, I.C.G. and Araujo-Murakami, A. and Arevalo, F.R. and Ramírez-Angulo, H. and Torre, E.V. and Peñuela, M.C. and Killeen, T.J. and Pardo, G. and Jimenez-Rojas, E. and Castro, W. and Cabrera, D.G. and Pipoly, J. and de Sousa, T.R. and Silvera, M. and Vos, V. and Neill, D. and Vargas, P.N. and Vela, D.M. and Aragão, L.E.O.C. and Umetsu, R.K. and Sierra, R. and Wang, O. and Young, K.R. and Prestes, N.C.C.S. and Massi, K.G. and Huaymacari, J.R. and Gutierrez, G.A.P. and Aldana, A.M. and Alexiades, M.N. and Baccaro, F. and Céron, C. and Muelbert, A.E. and Rios, J.M.G. and Lima, A.S. and Lloyd, J.L. and Pitman, N.C.A. and Gamarra, L.V. and Oroche, C.J.C. and Fuentes, A.F. and Palacios, W. and Patiño, S. and Torres-Lezama, A. and Baraloto, C. (2021) Amazon tree dominance across forest strata. Nature Ecology and Evolution, 5. pp. 757-767. ISSN 2397-334X

Abstract

The forests of Amazonia are among the most biodiverse plant communities on Earth. Given the immediate threats posed by climate and land-use change, an improved understanding of how this extraordinary biodiversity is spatially organized is urgently required to develop effective conservation strategies. Most Amazonian tree species are extremely rare but a few are common across the region. Indeed, just 227 ‘hyperdominant’ species account for >50% of all individuals >10 cm diameter at 1.3 m in height. Yet, the degree to which the phenomenon of hyperdominance is sensitive to tree size, the extent to which the composition of dominant species changes with size class and how evolutionary history constrains tree hyperdominance, all remain unknown. Here, we use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, midstory and canopy. We further find that, although species belonging to a range of phylogenetically dispersed lineages have become hyperdominant in small size classes, hyperdominants in large size classes are restricted to a few lineages. Our results demonstrate that it is essential to consider all forest strata to understand regional patterns of dominance and composition in Amazonia. More generally, through the lens of 654 hyperdominant species, we outline a tractable pathway for understanding the functioning of half of Amazonian forests across vertical strata and geographical locations.