Old-growth neotropical forests are shifting in species and trait composition

Tropical forests have long been thought to be in stable state, but recent insights indicate that global change is leading to shifts in forest dynamics and species composition. These shifts may be driven by environmental changes such as increased resource availability, increased drought stress, and/or recovery from past disturbances. The relative importance of these drivers can be inferred from analyzing changes in trait values of tree communities. Here, we evaluate a decade of change in species and trait composition across five old-growth Neotropical forests in Bolivia, Brazil, Guyana, and Costa Rica that cover large gradients in rainfall and soil fertility. To identify the drivers of compositional change, we used data from 29 permanent sample plots and measurements of 15 leaf, stem, and whole-plant traits that are important for plant performance and should respond to global change drivers. We found that forests differ strongly in their community-mean trait values, resulting from differences in soil fertility and annual rainfall seasonality. The abundance of deciduous species with high specific leaf area increases from wet to dry forests. The community-mean wood density is high in the driest forests to protect xylem vessels against drought cavitation, and is high in nutrient-poor forests to increase wood longevity and enhance nutrient residence time in the plant. Interestingly, the species composition changed over time in three of the forests, and the community-mean wood density increased and the specific leaf area decreased in all forests, indicating that these forests are changing toward later successional stages dominated by slow-growing, shade-tolerant species. We did not see changes in other traits that could reflect responses to increased drought stress, such as increased drought deciduousness or decreased m aximum adult size, or that could reflect increased resource availability (CO2, rainfall, or nitrogen). Changes in species and trait composition in these forests are therefore most likely caused by recovery from past disturbances. These compositional changes may also lead to shifts in ecosystem processes, such as a lower carbon sequestration and "slower" forest dynamics.

Bibliographic Details

Main Authors:	127244 Van der Sande, Masha T. Wageningen University, PO Box 47, 6700, AA Wageningen, The Netherlands, 43917 Arets, Eric J.M.M. (autor/a) Wageningen University and Research Centre, PO Box 47, 6700, AA Wageningen, The Netherlands, 104852 Peña Claros, Marielos (autor/a) Wageningen University and Research Centre, PO Box 47, 6700, AA Wageningen, The Netherlands, 45169 Avila, Angela Luciana de (autor/a) University of Freiburg, Tennenbacher Strasse 4, 79085, Freiburg, Germany, 113212 Roopsind, Anand (autor/a) University of Florida, P.O. 118526, 511 Bartram Hall, Gainesville, Florida 32611-8526, USA, 92149 Mazzei, Lucas (autor/a) Embrapa Amazônia Oriental, Travessa Enéas Pinheiro, S/N° 100 Belém, CEP 66095, Pará, Brazil, 44704 Ascarrunz, Nataly (autor/a) Instituto Boliviano de Investigación Forestal, Km 9 al Norte, El Vallecito, Santa Cruz de la Sierra, Bolivia, 67698 Finegan, Bryan (autor/a) CATIE (Centro Agronómico Tropical de Investigación y Enseñanza), 30501, Turrialba, Costa Rica, 40966 Alarcón, Alfredo (autor/a) Instituto Boliviano de Investigación Forestal, Km 9 al Norte, El Vallecito, Santa Cruz de la Sierra, Bolivia, 60630 Cáceres Siani, Yasmani (autor/a) Rurrenabaque, Beni, Bolivia, 86618 Licona, Juan Carlos (autor/a) Instituto Boliviano de Investigación Forestal, Km 9 al Norte, El Vallecito, Santa Cruz de la Sierra, Bolivia, 114149 Ruschel, Ademir (autor/a) Embrapa Amazônia Oriental, Travessa Enéas Pinheiro, S/N° 100 Belém, CEP 66095, Pará, Brazil, 124763 Toledo, Marisol (autor/a) Instituto Boliviano de Investigación Forestal, Km 9 al Norte, El Vallecito, Santa Cruz de la Sierra, Bolivia, 106286 Poorter, Lourens (autor/a) Wageningen University, PO Box 47, 6700, AA Wageningen, The Netherlands
Format:	Texto biblioteca
Language:	eng
Subjects:	AGRICULTURA, DINAMICA DE POBLACIONES, COMPOSICION BOTANICA, SUCESION ECOLOGICA, CAMBIO CLIMÁTICO, FERTILIDAD DEL SUELO, ESTACIONALIDAD, PRECIPITACION ATMOSFERICA, SEQUIA,
Online Access:	https://repositorio.catie.ac.cr/handle/11554/8486 https://doi.org/10.1890/15-1815.1
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