- Biodiversity,
- Tropical ecology
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.
Available at: http://works.bepress.com/john-pipoly/40/
We dedicate this study to the late Alwyn Gentry, who not only established 41 of the plots that form the foundation of our analyses but also pioneered the synthetic approach that underpins our study. This paper is a product of the RedGentry, RAINFOR, PPBio and ATDN networks. Data from many of these networks are curated by ForestPlots.net, a cyber-infrastructure initiative that unites plot records and their contributing scientists from the world’s tropical forests. These initiatives have been supported by numerous people and grants but we are indebted to hundreds of institutions, field assistants, botanists and local communities for help in establishing plots and identifying their >4,600 species. We would especially like to thank the following for their important role: E. Hase, R. Nazaré Oliveira de Araújo, S. Almeida, J. Serrano, J. Batista de Silva, K. Cangani, O. Souza Pereira, J. do Vale, M. Carmozina, E. da Costa Pereira, S. Salvino de Souza, C. Ballón Falcón, M. Corrales Medina, A. Magalhães da Silva, J. Farreras and F. Molina. F.C.D. was funded by an EU MSC global fellowship no. 794973 ‘E-FUNDIA’. F.C.D. and C.B. supported the collaborative network with funds from l’Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Florida International University and the William R. Kenan, Jr Charitable Trust. Funding for field plot data collection came from a wide range of sources but particularly the following grants: Conselho Nacional de Desenvolvimento Científico e Tecnológico/Projetos Ecológicos de Longa Duração-CNPq/PELD (grant no. 441244/2016-5), Agence Nationale de la Recherche Blanc projet NEBEDIV (grant no. ANR-13-BSV7-009), an ‘Investissement d’avenir’ grant from the Agence Nationale de la Recherche (CEBA, grant no. ANR-10-LABX-25-01), a Natural Environment Research Council (NERC) fellowship to T.R.B. (grant no. NE/C517484/1) and Spanish Ministry of Economy and Competitiveness (grant nos. CGL2015-72431-EXP and CGL2016-75414-P). Many bodies funded the development of RAINFOR and ForestPlots.net, with key support including from NERC (grant nos. NE/F005806/1, NE/D005590/1, NE/N012542/1 and NE/N011570/1), as well as the European Research Council (grant no. T-FORCES 291585) and Gordon and Betty Moore Foundation (grant no. 1656) to O.L.P. This study is no. 787 of the Technical Series of the Biological Dynamics of Forest Fragments (BDFFP-INPA). This is an output of ForestPlots.net approved Project 26. Re-evaluating hyperdominance across tree strata in Amazonia.