Middle to late Holocene fluctuations of C3 and C4 vegetation in a Northern New England Salt Marsh, Sprague Marsh, Phippsburg Maine

Average annual carbon sequestration rates for the last 2500 years approximate 40 g C yr−1 m−2, and are in strong agreement with other values published for the Gulf of Maine. Given that Maine salt marshes cover an area of ∼79 km2, they represent an important component of the terrestrial carbon sink. More detailed isotopic and age records from a network of sediment cores at Sprague Marsh are needed to truly evaluate the long term changes in salt marsh plant communities and the impact of more recent human activity, including global warming, on salt marsh vegetation.