Pilot Study of Sediment Accretion Methods and Rates in Prairie Potholes

摘要

Prairie potholes are small, shallow, ponded depressions of glacial origin (Sloan1972) comprising approximately 1 million of wetlands in North Dakota (Bigler and Richardson 1984). Potholes occur within the rolling terrain of glacial deposition as a series of closed or poorly drained basins. Prairie potholes serve as productive freshwater wetlands, providing primary waterfowl habitat for half the annual migratory waterfowl in the Mississippi Flyway (Smith, Stoudt, and Gollop 1964). They also provide water storage and groundwater recharge. Agricultural land use impacts prairie potholes by creating mobile sediments that can fill these wetlands. Nutrients and sediments from cultivated watersheds entering pothole basins promote the growth of vegetation that in turn traps additional sediment. Such anthropogenic effects may modify and reduce wetland habitat through the filling of the pothole basin (Martin and Hartman 1986), causing changes in hydrology and vegetation composition.