STABLE CARBON ISOTOPE ANALYSES OF SEDIMENTS CORES AND THE ORIGIN OF THE SPRAGUE RIVER MARSH, PHIPPSBURG, MAINE

Stable carbon isotope analyses of sediments provide a useful tracer for the presence of C4 plants in C3-dominated ecosystems. Upland plants in coastal Maine are dominated by C3 plants, whereas marsh plants are dominated by C4 plants. The purpose of this study is to use carbon isotopes in a network of sediment cores collected from the Sprague River marsh to determine the areas and depths whereat which salt marsh plants first appear. This spatial-temporal distribution of salt marsh plants will be used to invoke a mechanism for early marsh formation in the Sprague River marsh, a fluvial-minor marsh typically found in mid-coast Maine. Additionally, the total carbon stock of the marsh will be assessed.