Publication Date:
2022-05-25
Description:
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.
Description:
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.
Description:
This research was supported by a National Science Foundation
Graduate Fellowship.
Keywords:
Transpiration
;
Evaporation
;
Craig–Gordon enrichment
;
Evapotranspiration partitioning
;
Typha latifolia
;
Stable isotopes
;
Isotopic steady-state
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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