Monitoring and adaptation management of revegetation in the former Elwha Reservoirs

Dam removal on the Elwha River exposed over 280 hectares of valley slope, terrace, and floodplain landforms covered in millions of cubic meters of sediments deposited before and during dam removal. These sediments are either extremely coarse in texture (sands, gravels and cobbles) or very fine (silt and clay) and range in depth from 0.5 to 20 meters. This unprecedented condition dictated an adaptive management approach to revegetation. A seven-year revegetation plan that included over 90 permanent plots monitored annually was implemented to provide management with insight into natural and managed revegetation progress in these distinctly different sediment surfaces. With a focus on the former Lake Mills reservoir, the larger of the two reservoirs de-watered as a result of dam removal, I will present six years of data from the permanent plots showing how sediment texture, planting and seeding influenced all aspects of vegetation recovery