Role of Channel Migration in the Initiation and Maintenance of Forest Communities in Western Tennessee
Abstract
Forest regeneration was examined on abandoned channels and newly created point bars along the Hatchie River in western Tennessee. Tree age and size data are used to reconstruct the development of the young forest stands and to predict future changes. New point bar surfaces favor the establishment of Acer saccharinum and, to a lesser extent, Salix nigra and Populus deltoides. Taxodium distichum and S. nigra are the first species to colonize oxbow lakes after the channel cuts off. Longevity of the early colonizers is highly variable. S. nigra is short-lived, whereas T. distichum may dominate a site for more than 500 years. However, densities of all pioneer species on both abandoned channels and point bars decline with increasing age of surface. With the exception of A. saccharinum, these species have low reproductive success in mature strands and will be replaced by shade-tolerant species that establish much later. Therefore, the early colonizers rarely occur on older surfaces. Channel movement and the creation of new surfaces will maintain these species in the lower bottomlands of undisturbed streams. However, the initiation of pioneer communities may be precluded in some areas by stream channelization and bank stabilization. Maintaining straightened channels prevents formation of oxbows and point bars. Therefore, the primary regeneration surfaces for many species no longer exist.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1991
- Accession Number
- ADA236661
Entities
People
- David Shankman