Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.
Bibliographical noteFunding Information:
We acknowledge the following agencies for financial support: the Australian Department of Foreign Affairs and Trade-DFAT, the Biological Dynamics of Forest Fragments Project (BDFFP), the Blue Moon Foundation, CGIAR-FTA, CIFOR, COLCIENCIAS (grant no. PRE00503026837, 521, 2010), COLCIENCIAS (grant no. 1243-13-16640), Consejo Nacional de Ciencia y Tecnología (SEP-CONACYT 2009-129740 and SEP-CONACYT 2015-255544 for ReSerBos, SEP-CONACYT CB-2005-01-51043 and CB-2009-128136, CONACYT 33851-B, and SEMARNAT-CONACYT 2002 C01-0597), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 481576/2009-6, 563304/2010-3, 562955/2010-0, 574008/2008-0, 308778/2017-0, PQ 306375/2016-8, PQ 307422/2012-7, and PQ 309874/2015-7), FOMIX-Yucatan (YUC-2008-C06-108863), ForestGEO, Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM), Fundação de Amparo à Pesquisa de Minas Gerais (FAPEMIG CRA APQ-00001-11, PPM-00627-16), Fundación Ecológica de Cuixmala, the Global Environment Facility (GEF-grant VEN/SGP/2010-2015), the Heising-Simons Foundation, HSBC, the IAI Nitrogen Initiative, Investissement d'Avenir grant of the Agence Nationale de la Recherche (CEBA: ANR-10- LABX-25-01), ICETEX, Instituto Internacional de Educação do Brasil (IEB), Instituto Nacional de Ciência e Tecnologia dos Serviços Ambientais da Amazonia (INCT/Servamb), the Inter-American Institute for Global Change Research (Tropi-dry network CRN3-025) via a grant from the U.S. National Science Foundation (grant no. GEO-1128040), Intercolombia, the International Climate Initiative (IKI) of the German Federal Ministry for the Environment, the NASA Terrestrial Ecology Program, the National Science Foundation [NSF-CNH-RCN grant 1313788 for Tropical Reforestation Network: Building a Socioecological Understanding of Tropical Reforestation (PARTNERS), NSF DEB-0129104, NSF DEB-9972116, NSF BCS-1349952, NSF Career Grant DEB-1053237, NSF DEB-1050957, 0639393, 1147429, 0639114, and 1147434], Nature Conservation, Building and Nuclear Safety (BMUB), Netherlands Organisation for Scientific Research (NWO; grant no. NWO-ALWOP.241), the Norwegian Agency for Development Cooperation (Norad), NUFFIC, PAPIIT-DGAPA-UNAM IN213714 and IN218416, Science without Borders Program (CAPES/CNPq) (grant no. 88881.064976/2014-01), Stanley Motta, the Grantham Foundation for the Protection of the Environment, the São Paulo Research Foundation (FAPESP) (grant nos. 2011/06782-5 and 2014/14503-7), the United Nations Development Programme (Venezuela), Instituto Nacional de Investigaciones Agrícolas (INIA-Amazonas), the Silicon Valley Community Foundation, Stichting Het Kronendak, the Tropenbos Foundation, the University of Connecticut Research Foundation, USAID (BOLFOR), Wageningen University (INREF Terra Preta programme and FOREFRONT programme), and Yale-NUS College (grant no. R-607-265-054-121). This study was partly funded by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 283093 [Role Of Biodiversity In climate change mitigatioN (ROBIN)].