Embolism resistance supports the contribution of dry-season precipitation to transpiration in eastern Amazon forests
Abstract
Transpiration drives most of the local rainfall during the dry season in the Amazon forests by recycling moisture into the atmosphere. However, the source, temporal origin of transpiration, and spatial distribution of transpiration water sources remain unclear. Here, we quantify transpiration sources across a topographic gradient in the eastern Amazon. We show that on hills, dry-season transpiration sources are mostly shallow soil water recharged by dry-season rainfall. This is different in valleys, where tree water sources include both shallow and deep soil layers, with both dry- and wet-season contributions. We show that species embolism resistance largely explains this pattern in tree water use but with contrasting trade-offs between topographic positions. The significant relationship between embolism resistance and depth of water uptake in both hill and valley species may merit incorporation into process-based models to understand changes in vegetation and land surface fluxes.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (12)
Magali F. Nehemy
Department of Earth and Environmental Sciences, The University of British Columbia Okanagan
Caio R. C. Mattos
Department of Earth and Planetary Sciences, Rutgers University
Rafael S. Oliveira
Department of Plant Biology, Institute of Biology, University of Campinas
Marina Hirota
Ying Fan
Monique B. Schlickmann
School of Forest, Fisheries and Geomatics Sciences, University of Florida
Deliane Penha
Laboratório de Ecologia da Conservação Programa de Pós Graduação em Biodiversidade Universidade Federal do Oeste do Pará
Leandro L. Giacomin
Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba
Julliene S. G. M. Silva
Department of Plant Biology, Institute of Biology, University of Campinas
Mayda Rocha
Department of Plant Biology, Institute of Biology, University of Campinas
Gleicy A. Rodrigues
Laboratório de Ecologia da Conservação Programa de Pós Graduação em Biodiversidade Universidade Federal do Oeste do Pará
Jeffrey J. McDonnell
School of Environment and Sustainability, University of Saskatchewan