A Fifty-Year Record of Historical Sedimentation at Deer Lake, North Carolina

Abstract

Although many once-deforested areas of the eastern United States are now revegetated, impacts of this disturbance on watershed processes may persist. In this study, lake sediment stratigraphy and magnetism were used to assess the recovery of a small watershed in the southern Blue Ridge Mountains following abrupt reduction of human impacts. Average sediment yields were found to be higher than those of less disturbed basins nearby, and lower than those reported from the early twentieth-century Piedmont Province. Temporal trends in sediment yield appear to reflect both meteorological and land-use histories. Although most of the lake sediment is magnetically similar to bottomland sources, two instances of local upland sediment input, possibly related to human activities, are evident in the record. Interpreting relationships between sediment yield and changing environmental influences is impeded by poor temporal control in the methodology as well as by the intrinsic dynamics of the fluvial system.

*I thank Henry McNabb and the U.S. Forest Service at Bent Creek Experimental Forest for resources, useful discussion, historical information, and other means of facilitating this research. I am also indebted to I. L. Larsen, Oak Ridge National Laboratory, Environmental Sciences Division, for crucial assistance with Cs-137 counting.

Key Words:

• environmental magnetism
• lake sediment
• sediment source
• sediment yield

Notes

*I thank Henry McNabb and the U.S. Forest Service at Bent Creek Experimental Forest for resources, useful discussion, historical information, and other means of facilitating this research. I am also indebted to I. L. Larsen, Oak Ridge National Laboratory, Environmental Sciences Division, for crucial assistance with Cs-137 counting.

^aMica. stands for micaceous.

^b“Silt, sand” (or other sizes separated by a comma) indicates equal parts of each.

^cCore C4 was destroyed during transport subsequent to magnetism scan.