Assessing stand water use in four coastal wetland forests using sapflow techniques: annual estimates, errors and associated uncertainties

Hydrological Processes
By: , and 

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Abstract

Forests comprise approximately 37% of the terrestrial land surface and influence global water cycling. However, very little attention has been directed towards understanding environmental impacts on stand water use (S) or in identifying rates of S from specific forested wetlands. Here, we use sapflow techniques to address two separate but linked objectives: (1) determine S in four, hydrologically distinctive South Carolina (USA) wetland forests from 2009–2010 and (2) describe potential error, uncertainty and stand-level variation associated with these assessments. Sapflow measurements were made from a number of tree species for approximately 2–8 months over 2 years to initiate the model, which was applied to canopy trees (DBH > 10–20 cm). We determined that S in three healthy forested wetlands varied from 1.97–3.97 mm day−1 or 355–687 mm year−1 when scaled. In contrast, saltwater intrusion impacted individual tree physiology and size class distributions on a fourth site, which decreased S to 0.61–1.13 mm day−1 or 110–196 mm year−1. The primary sources of error in estimations using sapflow probes would relate to calibration of probes and standardization relative to no flow periods and accounting for accurate sapflow attenuation with radial depth into the sapwood by species and site. Such inherent variation in water use among wetland forest stands makes small differences in S (<200 mm year−1) difficult to detect statistically through modelling, even though small differences may be important to local water cycling. These data also represent some of the first assessments of S from temperate, coastal forested wetlands along the Atlantic coast of the USA.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Assessing stand water use in four coastal wetland forests using sapflow techniques: annual estimates, errors and associated uncertainties
Series title Hydrological Processes
DOI 10.1002/hyp.10130
Volume 29
Issue 1
Year Published 2015
Language English
Publisher Wiley
Contributing office(s) National Wetlands Research Center
Description 16 p.
First page 112
Last page 127
Online Only (Y/N) N
Additional Online Files (Y/N) N