MODERN AND PAST CARBON DYNAMICS IN PIERMONT MARSH, HUDSON RIVER ESTUARY

Understanding that 10-20% of all terrestrial carbon is stored within wetlands and forests collectively (United Nations University, 2008), we analyzed soil carbon concentrations in Piermont Marsh (73˚54’W, 41˚02’N), a brackish wetland in the Lower Hudson Valley. Soil carbon was measured along several transects at the surface and downcore at selected locations in order to access the spatial variability of the marsh. Loss-on-Ignition (LOI) was performed and the bulk density of sediments, water weight, and organic carbon were measured for a total of 99 samples along 17 transects. The data allows an understanding of carbon sequestration in the marsh and within stands of various vegetation types. Downcore and surface sediment samples were analyzed using a modified version of the Craft et al. (1991) formula for calculating percent Carbon from percent LOI. Results representing distinct regions show that a greater amount of carbon is stored where there is an abundance of water. A spatial contour map representing surface sediment samples demonstrates that carbon percentage increases towards the interior of the marsh and stays consistently low alongside stream banks. It was also found that S. patens, the native vegetation, and T. angustifolia, an invasive, store high amounts of carbon, while the carbon levels in P. australis stands vary across the marsh. Furthermore, probing was done using fiberglass rods to estimate a total depth of the marsh. A minimum depth of 9.1 meters was obtained at Crumkill creek and maximum depth of 17.7 meters was obtained along the banks of the Hudson River; this is a depth of four meters more than Peteet et al., cored in 2007. Future plans include using probing and core sample data to estimate total carbon stored in Piermont Marsh.