William H. Conner¹ and Rebecca R. Sharitz²

¹Baruch Institute of Coastal Ecology and Forest Science, Box 596, Georgetown, SC 29442, USA
²Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA

Abstract: Alluvial floodplains are geologically young sites in which sedimentation and erosion are the dominant geologic processes. Two of the most important characteristics of these floodplain ecosystems are change and diversity. Because of flooding, sediment deposition, and stream movement, floodplain sites are constantly changing, and this change has a marked influence on natural forest development. Primary succession occurs on new land formed by deposition (e.g., sandbars and mud flats), and secondary succession on other sites is often driven or influenced by depositional patterns. Site diversity occurs as a result of minor differences in relief that are the result of stream meander and depositional patterns. Species occurrence and diversity within the floodplains are strongly related to these site differences, primarily because of differences in hydrology (drainage). Forest management practices within these floodplains should consider topographic site differences and attempt to match species to the appropriate sites. This consideration is especially important for restoration projects and managed regeneration of harvested areas. Alluvial floodplains provide very productive habitat, and maintenance of that habitat is generally compatible with forestry practices designed to produce and enhance timber quality. Planning and management decisions at the landscape level are needed to address ecological concerns such as biodiversity, water flows, and forest fragmentation. Timber removal and forest regeneration practices can then be used to optimize diversity, dispersion, and juxtaposition of habitat types across the landscape.