1. Precipitation mediates sap flux sensitivity to evaporative demand in the neotropics
- Author
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Chonggang Xu, Damien Bonal, Georgianne W. Moore, Lara M. Kueppers, Kolby J. Jardine, Claire Fortunel, Volodymyr Trotsiuk, Nathan G. Swenson, Clarissa G. Fontes, Isaac Borrego, Bradley O. Christoffersen, Liang Wei, Brett T. Wolfe, Nate G. McDowell, Charlotte Grossiord, Jeffrey M. Warren, Robinson I. Negrón-Juárez, D. S. Christianson, L. M. T. Aparecido, Matteo Detto, Benoit Burban, Heidi Asbjornsen, Kristina J. Anderson-Teixeira, Z. Carter Berry, Jeffrey Q. Chambers, Gretchen R. Miller, Boris Faybishenko, Aura M. Alonso-Rodríguez, Clément Stahl, Tana E. Wood, Bruno O. Gimenez, Charu Varadharajan, Christopher Baraloto, Swiss Federal Institute for Forest, Snow and Avalanche Research WSL, School of Geosciences [Edinburgh], University of Edinburgh, Smithsonian Conservation Biology Institute, Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), SILVA (SILVA), Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Lorraine (UL), United States Department of Energy, Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Neuroscience, New York State Psychiatric Institute, Czech University of Life Science, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL)-AgroParisTech, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Los Alamos National Laboratory (LANL), and Pacific Northwest National Laboratory (PNNL)
- Subjects
0106 biological sciences ,Vapor Pressure ,Vapour Pressure Deficit ,Humid subtropical climate ,Flux ,Biology ,Forests ,Atmospheric sciences ,[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy ,010603 evolutionary biology ,01 natural sciences ,Trees ,Transpiration ,Vapor pressure deficit ,Atmosphere ,[SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems ,Evapotranspiration ,Plant functional traits ,Precipitation ,Ecology, Evolution, Behavior and Systematics ,Ecology ,010604 marine biology & hydrobiology ,Water ,Plant Transpiration ,15. Life on land ,[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics ,Droughts ,13. Climate action ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Water use - Abstract
International audience; Transpiration in humid tropical forests modulates the global water cycle and is a key driver of climate regulation. Yet, our understanding of how tropical trees regulate sap flux in response to climate variability remains elusive. With a progressively warming climate, atmospheric evaporative demand [i.e., vapor pressure deficit (VPD)] will be increasingly important for plant functioning, becoming the major control of plant water use in the twenty-first century. Using measurements in 34 tree species at seven sites across a precipitation gradient in the neotropics, we determined how the maximum sap flux velocity (vmax) and the VPD threshold at which vmax is reached (VPDmax) vary with precipitation regime [mean annual precipitation (MAP); seasonal drought intensity (PDRY)] and two functional traits related to foliar and wood economics spectra [leaf mass per area (LMA); wood specific gravity (WSG)]. We show that, even though vmax is highly variable within sites, it follows a negative trend in response to increasing MAP and PDRY across sites. LMA and WSG exerted little effect on vmax and VPDmax, suggesting that these widely used functional traits provide limited explanatory power of dynamic plant responses to environmental variation within hyper-diverse forests. This study demonstrates that long-term precipitation plays an important role in the sap flux response of humid tropical forests to VPD. Our findings suggest that under higher evaporative demand, trees growing in wetter environments in humid tropical regions may be subjected to reduced water exchange with the atmosphere relative to trees growing in drier climates.
- Published
- 2019