The application of δ18O and δD for understanding water pools and fluxes in a Typha Marsh
Bijoor, Neeta S.
Pataki, Diane E.
Rocha, Adrian V.
Goulden, Michael L.
MetadataShow full item record
KeywordTranspiration; Evaporation; Craig–Gordon enrichment; Evapotranspiration partitioning; Typha latifolia; Stable isotopes; Isotopic steady-state
The δ18O and δD composition of water pools (leaf, root, standing water, and soil water) and fluxes (transpiration, evaporation) were used to understand ecohydrological processes in a managed Typha latifolia L. freshwater marsh. We observed isotopic steady state transpiration and deep rooting in Typha. The isotopic mass balance of marsh standing water showed that evaporation accounted for 3% of the total water loss, transpiration accounted for 17%, and subsurface drainage accounted for the majority, 80%. There was a vertical gradient in water vapor content and isotopic composition within and above the canopy sufficient for constructing an isotopic mass balance of water vapor during some sampling periods. During these periods, the proportion of transpiration in evapotranspiration (T/ET) was between 56 ± 17% to 96 ± 67%, and the estimated error was relatively high (>37%) due to non-local, background sources in vapor. Independent estimates of T/ET using eddy covariance measurements yielded similar mean values during the Typha growing season. The various T/ET estimates agreed that transpiration was the dominant source of marsh vapor loss in the growing season. The isotopic mass balance of water vapor yielded reasonable results, but the mass balance of standing water provided more definitive estimates of water losses.
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Plant, Cell & Environment 34 (2011): 1761-1775, doi:10.1111/j.1365-3040.2011.02372.x.
Showing items related by title, author, creator and subject.
Observations of Li isotopic variations in the Trinity Ophiolite : evidence for isotopic fractionation by diffusion during mantle melting Lundstrom, Craig C.; Chaussidon, Marc; Hsui, Albert T.; Kelemen, Peter B.; Zimmerman, Mark (2004-08-10)The Trinity peridotite (northern CA) contains numerous lithologic sequences consisting of dunite to harzburgite to spinel lherzolite to plagioclase lherzolite. Previous workers have documented geochemical gradients in these ...
White, Helen K. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-02)To provide a new perspective on the fate of both natural organic matter and hydrophobic organic contaminants (HOCs) in marine sediments, we have investigated the relationship between radiocarbon (14C) age and the different ...
Sachs, Julian P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1997-02)The goals of this thesis were: (1) to establish methods for the determination of nitrogen and carbon isotope ratios in marine particulate and sedimentary chlorophyll derivatives; (2) to establish chlorophyll δ15N and ...