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Abstract The long‐term stability of coastal wetlands is determined by interactions among sea level, plant primary production, sediment supply, and wetland vertical accretion. Human activities in watersheds have significantly altered sediment delivery from the landscape to the coastal ocean, with declines along much of the U.S. East Coast. Tidal wetlands in coastal systems with low sediment supply may have limited ability to keep pace with accelerating rates of sea‐level rise (SLR). Here, we show that rates of vertical accretion and carbon accumulation in nine tidal wetland systems along the U.S. East Coast from Maine to Georgia can be explained by differences in the rate of relative SLR (RSLR), the concentration of suspended sediments in the rivers draining to the coast, and temperature in the coastal region. Further, we show that rates of vertical accretion have accelerated over the past century by between 0.010 and 0.083 mm yr−2, at roughly the same pace as the acceleration of global SLR. We estimate that rates of carbon sequestration in these wetland soils have accelerated (more than doubling at several sites) along with accelerating accretion. Wetland accretion and carbon accumulation have accelerated more rapidly in coastal systems with greater relative RSLR, higher watershed sediment availability, and lower temperatures. These findings suggest that the biogeomorphic feedback processes that control accretion and carbon accumulation in these tidal wetlands have responded to accelerating RSLR, and that changes to RSLR, watershed sediment supply, and temperature interact to determine wetland vulnerability across broad geographic scales.
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Rates of vertical accretion of backbarrier marshes along the Georgia Bight as measured from sediment cores collected during December 2017 (NCEI Accession 0286629)
Data set of measured sediment characteristics and vertical accretion rates of backbarrier marshes along the Georgia Bight. Data include bulk density (g/cm^3), water content (%), organic content (%), Pb-210 (Bq/kg), Cs-137 (Bq/kg), and calculated rates of vertical accretion (mm/yr) as measured from sediment cores collected during December 2017. Data are provided as CSV files.
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- PAR ID:
- 10519593
- Publisher / Repository:
- NOAA National Centers for Environmental Information
- Date Published:
- Format(s):
- Medium: X
- Location:
- (East Bound Longitude:-79.1716861111; North Bound Latitude:33.3501083333; South Bound Latitude:30.539875971; West Bound Longitude:-81.5158677806)
- Institution:
- Virginia Institute of Marine Science
- Sponsoring Org:
- National Science Foundation
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