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Title: Biophysical controls of marsh soil shear strength along an estuarine salinity gradient
Abstract. 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 marshesmay lead to simultaneous losses in biodiversity and erodibility.  more » « less
Award ID(s):
1654374
NSF-PAR ID:
10292690
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Earth Surface Dynamics
Volume:
9
Issue:
3
ISSN:
2196-632X
Page Range / eLocation ID:
413 to 421
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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