Dead Wood: Geomorphic Effects of Coarse Woody Debris in Headwater Streams, Great Smoky Mountains
Hart EA. 2003. Dead Wood: Geomorphic Effects of Coarse Woody Debris in Headwater Streams, Great Smoky Mountains. Journal of the Tennessee Academy of Science. 78(2):50-54
Coarse woody debris (CWD) is an important component of headwater streams. This study compares the distribution, residence time, and geomorphic function of CWD between two headwater streams, one located in an area of the Great Smoky Mountains that was logged 80 years ago and the other in an old growth forest zone. Coarse woody debris channel obstructions are more frequent along the old growth-area stream (3.0 per 100 m) compared with the logged-area stream (1.4 per 100 m). Differences in CWD frequency and size between the two reaches have important consequences for observed variations in channel morphology and sediment storage. Coarse woody debris stores approximately 25 times more sediment along the old growth reach than along the logged-area reach. In addition, variations in channel width and longitudinal profile are more closely tied with variations in CWD frequency along the old growth stream. The greatest effect of CWD on channel morphology occurs where debris slides have delivered multiple trees to headwater streams creating 'log jams.' One log jam consists of over 50 trees and stores ~1200 m3 of sand and gravel. Future investigations should focus on monitoring sediment release from large log jams since such releases may dramatically affect downstream channel morphology and basin sediment yield.
- Type
- Journal Article
- Authors
- Hart, Evan
- Units
- GRSM
- Keywords
- APHN, Appalachian Highlands Network, Channel Morphology, coarse woody debris, CWD, Great Smoky Mountains National Park, GRSM, GRSM-00603, headwater streams, Huskey Branch, log jam, Old Growth, Road Prong, SER, Southeast Region
- Subjects
- Ecological Framework: Geology and Soils | Geomorphology | Stream/River Channel Characteristics