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Monday, May 26, 2008 - 2:15 PM
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Stability restoration projects on coastal plain stream channels: Geomorphic and biologic effects
Brian Laub, Entomology, University of Maryland, Plant Sciences 4112, College Park, MD 20742 and Margaret Palmer, Chesapeake Biological Laboratory, University of Maryland, Solomons, MD 20688.
The number of stream restoration projects has increased exponentially in recent years, but their impact on stream communities is rarely assessed. One costly and widespread type of restoration is stability restoration, a combination of bank stabilization and channel reconfiguration. Such restoration projects are a direct manipulation of the geomorphic complexity of stream channels and offer an ideal system in which to test relationships between complexity and biological communities. We surveyed complexity on forested, urbanized, and restored first and second-order streams in Maryland’s coastal plain. We measured width, depth, velocity, and particle size distributions at multiple transects and transient storage zone using solute pulse releases. We are also measuring diatom diversity to see if diversity is related to complexity. Results suggest that restored streams differ in their geomorphic properties compared to forested but not urbanized streams. However, restored streams are not more or less complex overall than forested or urbanized streams. These measurements provide a way to integrate effects of small-scale geomorphic features such as logs and boulders into reach-wide complexity metrics. Our assessment of diatom diversity is ongoing, and to date we have identified 23 species. The next step is to determine whether complexity influences diatom response to flood disturbance.
Web Page: stream restoration, geomorphic, stability