Sediment accretion in tidal freshwater forests and oligohaline marshes of the Waccamaw and Savannah Rivers, USA

Estuaries and Coasts
By: , and 



Sediment accretion was measured at four sites in varying stages of forest-to-marsh succession along a fresh-to-oligohaline gradient on the Waccamaw River and its tributary Turkey Creek (Coastal Plain watersheds, South Carolina) and the Savannah River (Piedmont watershed, South Carolina and Georgia). Sites included tidal freshwater forests, moderately salt-impacted forests at the freshwater–oligohaline transition, highly salt-impacted forests, and oligohaline marshes. Sediment accretion was measured by use of feldspar marker pads for 2.5 year; accessory information on wetland inundation, canopy litterfall, herbaceous production, and soil characteristics were also collected. Sediment accretion ranged from 4.5 mm year−1 at moderately salt-impacted forest on the Savannah River to 19.1 mm year−1 at its relict, highly salt-impacted forest downstream. Oligohaline marsh sediment accretion was 1.5–2.5 times greater than in tidal freshwater forests. Overall, there was no significant difference in accretion rate between rivers with contrasting sediment loads. Accretion was significantly higher in hollows than on hummocks in tidal freshwater forests. Organic sediment accretion was similar to autochthonous litter production at all sites, but inorganic sediment constituted the majority of accretion at both marshes and the Savannah River highly salt-impacted forest. A strong correlation between inorganic sediment accumulation and autochthonous litter production indicated a positive feedback between herbaceous plant production and allochthonous sediment deposition. The similarity in rates of sediment accretion and sea level rise in tidal freshwater forests indicates that these habitats may become permanently inundated if the rate of sea level rise increases.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Sediment accretion in tidal freshwater forests and oligohaline marshes of the Waccamaw and Savannah Rivers, USA
Series title Estuaries and Coasts
DOI 10.1007/s12237-013-9744-7
Volume 37
Issue 5
Year Published 2014
Language English
Publisher Springer
Contributing office(s) National Research Program - Eastern Branch
Description 13 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Estuaries and Coasts
First page 1107
Last page 1119
Country United States
State Georgia;South Carolina
Other Geospatial Savannah River;Waccamaw River
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