Biophysical controls of marsh soil shear strength along an estuarine salinity gradient
Gillen, Megan N.
Messerschmidt, Tyler C.
Kirwan, Matthew L.
MetadataShow full item record
Sea-level rise, saltwater intrusion, and wave erosion threaten coastal marshes, but the influence of salinity on marsh erodibility remains poorly understood. We measured the shear strength of marsh soils along a salinity and biodiversity gradient in the York River estuary in Virginia to assess the direct and indirect impacts of salinity on potential marsh erodibility. We found that soil shear strength was higher in monospecific salt marshes (5–36 kPa) than in biodiverse freshwater marshes (4–8 kPa), likely driven by differences in belowground biomass. However, we also found that shear strength at the marsh edge was controlled by sediment characteristics, rather than vegetation or salinity, suggesting that inherent relationships may be obscured in more dynamic environments. Our results indicate that York River freshwater marsh soils are weaker than salt marsh soils, and suggest that salinization of these freshwater marshes may lead to simultaneous losses in biodiversity and erodibility.
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gillen, M. N., Messerschmidt, T. C., & Kirwan, M. L. Biophysical controls of marsh soil shear strength along an estuarine salinity gradient. Earth Surface Dynamics, 9(3),(2021): 413-421, https://doi.org/10.5194/esurf-9-413-2021.
Suggested CitationGillen, M. N., Messerschmidt, T. C., & Kirwan, M. L. (2021). Biophysical controls of marsh soil shear strength along an estuarine salinity gradient. Earth Surface Dynamics, 9(3), 413–421.
The following license files are associated with this item: