Loading...
The effect of a small vegetation dieback event on salt marsh sediment transport
Coleman, Daniel J. Kirwan, Matthew L.
Coleman, Daniel J.
Kirwan, Matthew L.
Abstract
Vegetation is a critical component of the ecogeomorphic feedbacks that allow a salt marsh to build soil and accrete vertically. Vegetation dieback can therefore have detrimental effects on marsh stability, especially under conditions of rising sea levels. Here, we report a variety of sediment transport measurements associated with an unexpected, natural dieback in a rapidly prograding marsh in the Altamaha River Estuary, Georgia. We find that vegetation mortality led to a significant loss in elevation at the dieback site as evidenced by measurements of vertical accretion, erosion, and surface topography compared to vegetated refer- ence areas. Below-ground vegetation mortality led to reduced soil shear strength. The dieback site displayed an erosional, concave-up topographic profile, in contrast to the reference sites. At the location directly impacted by the dieback, there was a reduction in flood dominance of suspended sediment concentration. Our work illustrates how a vegetation disturbance can at least temporarily reverse the local trajectory of a prograding marsh and produce complex patterns of sediment transport.
Description
Date
2019-01-01
Journal Title
Journal ISSN
Volume Title
Publisher
Collections
Download Dataset
Files
Loading...
Coleman_GA_onefile.pdf
Adobe PDF, 1.14 MB
Rights Holder
Usage License
Embargo
Research Projects
Organizational Units
Journal Issue
Keywords
Physical Sciences Peer-Reviewed Articles, dieback; sediment transport; salt marsh; erosion; vegetation
Citation
Advisor
Department
Virginia Institute of Marine Science
DOI
https://doi.org/10.1002/esp.4547