RIVERINE WETLAND EVOLUTION, PERSISTENCE, DESTRUCTION, AND RESTORATION IN THE UPPER LITTLE TENNESSEE RIVER BASIN, SOUTHERN BLUE RIDGE MOUNTAINS, NORTH CAROLINA

Wetlands on bottomlands of rivers and streams in the Blue Ridge Mountains were much more common in the prehistoric past than they are now. Many wetlands were artificially ditched and drained, beavers were removed, and some wetlands are covered by thick deposits of Euro-American overbank flood sediment derived from mechanized erosive land use practices. Landscape evolution of wetlands is revealed by several case studies of wetland restoration projects on bottomlands along the upper Little Tennessee River and nearby tributaries. High-resolution (1 m pixel width) LiDAR topographic data are used in conjunction with sedimentologic, stratigraphic, and radiocarbon dating methods to evaluate landscape settings and evolution of individual bottomlands slated for wetland restoration. In addition, archaeological surveys are conducted to understand the cultural resources bordering wetlands. Results indicate a geomorphic pattern of prehistoric wetlands that occurred within back-levee backswamps and within meander scars. Some of the wetlands persisted essentially for the entire Holocene, until artificially drained, based on basal radiocarbon dates beneath peat, mucky peat, and gleyed clay- and organic-rich vertical accretion deposits. Radiocarbon dates indicate that at least some portions of the upper Little Tennessee River and its tributaries had established stream bed elevations equal to that of modern levels by 10-11 ka, refuting the idea of later Holocene incision and terrace formation. Early through late Holocene meander scars on the bottomlands of the river and tributaries indicate single-thread meandering channels and counter the notion that multi-thread, anabranching wetland systems dominated prior to Euro-American disturbance. Thicknesses of Euro-American vertical accretion deposits range from negligible to >1 meter, depending on specific geomorphic settings and distance from the river channel. Archaeological surveys confirm prehistoric use of land immediately adjacent to some of the former wetlands. In summary, wetland restoration projects are providing key insights and data leading to a much better understanding of the Holocene landscape evolution and human occupation of river and stream valleys in the Southern Blue Ridge Mountains.