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Author Grossiord, C.; Christoffersen, B.; Alonso-Rodríguez, A.M.; Anderson-Teixeira, K.; Asbjornsen, H.; Aparecido, L.M.T.; Carter Berry, Z.; Baraloto, C.; Bonal, D.; Borrego, I.; Burban, B.; Chambers, J.Q.; Christianson, D.S.; Detto, M.; Faybishenko, B.; Fontes, C.G.; Fortunel, C.; Gimenez, B.O.; Jardine, K.J.; Kueppers, L.; Miller, G.R.; Moore, G.W.; Negron-Juarez, R.; Stahl, C.; Swenson, N.G.; Trotsiuk, V.; Varadharajan, C.; Warren, J.M.; Wolfe, B.T.; Wei, L.; Wood, T.E.; Xu, C.; McDowell, N.G.
Title Precipitation mediates sap flux sensitivity to evaporative demand in the neotropics Type Journal Article
Year 2019 Publication Oecologia Abbreviated Journal Oecologia
Volume 191 Issue 3 Pages 519-530
Keywords Evapotranspiration; Plant functional traits; Transpiration; Vapor pressure deficit; drought; evapotranspiration; flux measurement; hydrological cycle; Neotropical Region; precipitation (chemistry); precipitation (climatology); tree; tropical forest; tropical region; vapor pressure; water; drought; evapotranspiration; forest; tree; vapor pressure; Droughts; Forests; Plant Transpiration; Trees; Vapor Pressure; Water
Abstract 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. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
Address Earth Systems Science Division, Pacific Northwest National Laboratory, Richland, WA, United States
Corporate Author Thesis
Publisher (up) Springer Verlag Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 00298549 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 904
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Author Denis, T.; Richard-Hansen, C.; Brunaux, O.; Guitet, S.; Hérault, B.
Title Birds of a feather flock together: Functionally similar vertebrates positively co-occur in Guianan forests Type Journal Article
Year 2019 Publication Ecosphere Abbreviated Journal Ecosphere
Volume 10 Issue 3 Pages e02566
Keywords activity matching; birds; Guiana Shield; information exchange; mammals; mixed-species associations; mutualism; terra firme rainforests
Abstract Medium- and large-sized vertebrates play a key role in shaping overall forest functioning. Despite this, vertebrate interactions, from competition to mutualism, remain poorly studied, even though these interactions should be taken into account in our conservation and management strategies. Thus, we tackled the question of vertebrate co-occurrence in tropical rainforests: Are (negative or positive) co-occurrences dependent on forest structure and composition? and Are these co-occurrences linked to functional species similarity? We recorded the occurrence of 21 medium- and large-sized vertebrates in 19 French Guianan locations in which a large set of forest structure and composition descriptors were collected. We used a probabilistic model to look for co-occurrences at different spatial scales, and species pairwise co-occurrences were then compared to those generated solely on the basis of forest structure and composition. We then quantified the co-occurrence strength between pairwise species dyads and determined whether they relied on species functional similarity, controlling for the environmental effects. We found that positive co-occurrences vastly outnumbered negative co-occurrences, were only partly shaped by the local environment, and were closely linked to species functional similarity. Thus, groups of species sharing similar functional traits are more prone to co-occur, highlighting the key role of functional redundancy in structuring species assemblages. We discuss how positive interactions could generate the predominance of positive co-occurrences in oligotrophic terra firme (unflooded) forests when resources are scarce and dispersed in dry season. Finally, we identified functional groups based on co-occurrence strength and suggested that frugivory/granivory and body size are of primary importance in species interactions in Neotropical vertebrate communities. © 2019 The Authors.
Address INPHB, Institut National Polytechnique Félix Houphouët-Boigny, Yamoussoukro, Cote d'Ivoire
Corporate Author Thesis
Publisher (up) Wiley-Blackwell Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 21508925 (Issn) ISBN Medium
Area Expedition Conference
Notes Export Date: 16 March 2020; Correspondence Address: Denis, T.; Office National de la Chasse et de la Faune Sauvage, UMR EcoFoG (AgroParisTech, Cirad, CNRS, INRA, Université des Antilles, Université de Guyane)France; email: thomas.denis@ecofog.gf Approved no
Call Number EcoFoG @ webmaster @ Serial 924
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