Cellulose (delta)18O is an index of leaf-to-air vapor pressure difference (VPD) in tropical plants
JournalArticle (Originalarbeit in einer wissenschaftlichen Zeitschrift)
ID 2106219
Author(s) Kahmen, Ansgar; Sachse, Dirk; Arndt, Stefan K.; Tu, Kevin P.; Farrington, Heraldo; Vitousek, Peter M.; Dawson, Todd E.
Author(s) at UniBasel Kahmen, Ansgar
Year 2011
Title Cellulose (delta)18O is an index of leaf-to-air vapor pressure difference (VPD) in tropical plants
Journal Proceedings of the National Academy of Sciences
Volume 108
Number 5
Pages / Article-Number 1981-6
Abstract Cellulose in plants contains oxygen that derives in most cases from precipitation. Because the stable oxygen isotope composition, δ(18)O, of precipitation is associated with environmental conditions, cellulose δ(18)O should be as well. However, plant physiological models using δ(18)O suggest that cellulose δ(18)O is influenced by a complex mix of both climatic and physiological drivers. This influence complicates the interpretation of cellulose δ(18)O values in a paleo-context. Here, we combined empirical data analyses with mechanistic model simulations to i) quantify the impacts that the primary climatic drivers humidity (e(a)) and air temperature (T(air)) have on cellulose δ(18)O values in different tropical ecosystems and ii) determine which environmental signal is dominating cellulose δ(18)O values. Our results revealed that e(a) and T(air) equally influence cellulose δ(18)O values and that distinguishing which of these factors dominates the δ(18)O values of cellulose cannot be accomplished in the absence of additional environmental information. However, the individual impacts of e(a) and T(air) on the δ(18)O values of cellulose can be integrated into a single index of plant-experienced atmospheric vapor demand: the leaf-to-air vapor pressure difference (VPD). We found a robust relationship between VPD and cellulose δ(18)O values in both empirical and modeled data in all ecosystems that we investigated. Our analysis revealed therefore that δ(18)O values in plant cellulose can be used as a proxy for VPD in tropical ecosystems. As VPD is an essential variable that determines the biogeochemical dynamics of ecosystems, our study has applications in ecological-, climate-, or forensic-sciences.
Publisher National Academy of Sciences
ISSN/ISBN 0027-8424 ; 1091-6490
edoc-URL http://edoc.unibas.ch/49359/
Full Text on edoc No
Digital Object Identifier DOI 10.1073/pnas.1018906108
PubMed ID http://www.ncbi.nlm.nih.gov/pubmed/21245322
ISI-Number WOS:000286804700045
Document type (ISI) Journal Article

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