Abstract

Every year since 2000, five to ten ecological restoration projects have been implemented on public and private lands in the Puget Sound region of Washington State by the University of Washington Restoration Ecology Network (UW-REN) capstone program. Students, faculty, and community partners have collaborated to implement these restoration projects, improve ecological function at the sites, and build site stewardship. Approximately twenty-nine, 2,000 m2 projects from the first ten years of the capstone projects were retrospectively evaluated using a variety of response variables that could reflect ecological “success”, including native species cover, richness, and diversity in the restoration plant community. We hypothesized that certain elements of restoration design and implementation, such as selected techniques for invasive vegetation management and the resulting degree of site stewardship, would strongly contribute to the success of these restoration projects. Stewardship was found to contribute to native species cover, richness, and diversity. Native plant species richness and diversity responded to initial invasive control techniques; stem-only removal did not work as well as root system removal for native species richness or diversity. The use of wood chip and cardboard-with-wood chip sheet mulches had less clear effects on species richness. An interaction between mulch and control technique was found to contribute to species diversity evenness. Overall, this study of restoration projects led by university students in cooperation with community partners highlights the importance of specific elements of restoration design and implementation and due diligence in the form of long-term stewardship.

pdf