Accretion Response of Soils in a Restored and Natural Tidal Marsh Under Rapid Relative Sea Level Rise

Concerns over the mitigation of global warming and the impacts of rising sea levels caused by global warming have focused attention on tidal wetlands. The restoration and management of tidal wetlands may allow such areas to sequester carbon, helping to mitigate global warming, while the accumulation of organic materials may help prevent the marshes from being inundated by rising sea levels. We are sampling and monitoring soils on a natural marsh and a marsh restored in 2003 with locally derived dredged materials to determine organic matter accumulation rates, quantify carbon sequestration, and estimate accretion rates. Samples were collected in 2006 and 2007. The emissions of methane, a potent greenhouse gas, are also being monitored. This research is being performed in collaboration with the National Aquarium in Baltimore and the USGS Patuxent Wildlife Research Center. We will discuss measurement methods, study results, an innovative method to establish a sampling reference plane across years, and implications of tidal marshes as greenhouse gas sinks and sources.