Hood, W.G., 2007. Large woody debris influences vegetation zonation in an oligohaline tidal marsh. Estuaries and Coasts, 30, pp.441-450. [NOTE: The download link for this document leads offsite]

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The amount of large woody debris (LWD) in Pacific Northwest estuaries has declined dramatically since Euro-
American settlement in the mid 19th century. Little is known about the ecological significance of estuarine LWD. This
ignorance impairs protection and restoration of habitat critical to threatened Chinook salmon (Oncorhynchus tshawytscha), as
well as other fish and wildlife. This study investigates whether LWD affects the distribution of estuarine shrubs, particularly
nitrogen-fixing Myrica gale L. (sweetgale), which dominates the tidal shrub community of the Skagit River estuary,
Washington, U.S.A. LWD, M. gale, and other shrubs were surveyed along line transects in an oligohaline tidal marsh and in
abandoned agricultural land whose dikes failed more than 50 years ago and which has reverted to marsh. The results
demonstrate a strong association between LWD and M. gale. M. gale was very rare on LWD , 30 cm in diameter, increasingly
more common for LWD between 30 and 75 cm, and always present on LWD $ 75 cm. The marsh surface was generally 45 cm
below mean higher high water (MHHW), suggesting LWD benefits M. gale by providing a growth platform at an elevation near
MHHW and reducing flooding stress. The largest and most abundant tree in the marsh, Picea sitchensis, averaged only 35.8 cm
in diameter, which suggests LWD recruitment from upstream sources is necessary to sustain M. gale populations in the
geomorphologically dynamic Skagit marsh. By affecting the distribution and abundance of M. gale in the estuary, LWD may
indirectly affect nitrogen dynamics in the marsh and secondary production of detritivores and herbivores

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