Large wood supports Elwha revegetation by reducing ungulate browsing

Introduction The increasing number of dams approaching obsolescence drives a need for knowledge about riparian restoration associated with dam removal. Restoring woody vegetation on exposed reservoir beds following removal is essential to stabilizing sediment, reconnecting riverine and terrestrial systems, providing future sources shade, nutrients, wood. Revegetation after many rivers can be challenging due rapidly drying low sediment nutrient content, heavy ungulate browse pressure. in Elwha River restoration, the largest date, used large debris (LWD) mitigate moisture limitation but browsing has constrained plant growth coarse deposits. We evaluated potential LWD reduce Methods studied mitigation former comparable valley upriver natural floodplain. measured intensity randomly located plots stratified by four levels extent, from no complete enclosure. Results reduced four-fold reservoir, only fully surrounded LWD. Partial enclosure provided little reduction. obtained similar results valley, where was somewhat lower except within wood clusters. Wood-mediated reduction slightly greater than valley. Protection greatest species preferred ungulates. Discussion These suggest forest expedited surrounding young trees logs. Planting clusters or placing sites facilitate establishment islands strategic locations. support dispersal seeds marine derived reconnect established river, potentially advance decades.