| Popis: |
Vertical marsh accretion, along with sediment and nutrient accumulation, were examined using 137Cs dating and chemical analysis of soil cores taken from various marshes in Louisiana's Barataria Basin. Vertical accretion averaged 1.3 cm yr-1 and 0.7 cm yr-1 in levee and backmarsh areas respectively. Inorganic sedimentation increased fourfold from freshwater through salt marshes along a transect perpendicular to the Gulf Coast. The accretionary role of inorganic sediments is variable according to marsh type. Mineral sediment being deposited in the marsh is the principle source of iron, manganese, and phosphorus, but not of organic carbon or nitrogen. Manganese and phosphorus appear to be subject to substantial post-depositional remobilization. |
