Stream channelization and changing vegetation patterns in the US coastal plain

Plant-community patterns in the alluvial wetlands of the southeastern U.S. Coastal Plain are highly complex, depending on the hydroperiod, the height of the water table, the age of the surface age, and a variety of natural and human-induced disturbances. The range of physical conditions that many terrestrial species on lower bottomland sires require to maintain themselves and regenerate is narrow. Stream channelization causes a dramatic alteration of the magnitude and duration of flooding and sedimentation, and it precludes channel migration. These changes in hydrogeomorphic processes disrupt critical river-floodplain interactions, which in many cases alter the conditions of bottomland habitats and the composition of plant communities, The modified hydrology along some stream segments, in particular lower peak discharges in the upper sections of watersheds caused by channelization, has promoted deforestation and land-use conversion to agriculture.