Glines Canyon Dam and Elwha Dam in the Elwha River Valley are planned for removal beginning in 2007. Sediments underlying waters impounded by these two dams (Lake Mills and Lake Aldwell) are low in nutrients and are very unlikely to contain viable spores from mycorrhizal fungi. The infection of vascular plant roots by mycorrhizal fungi causes plants to form fine roots which in turn facilitates uptake of nutrients and water by the plant. This symbiotic infection is necessary for rapid plant growth; lack of infection is known to cause plant mortality, particularly on harsh sites. Determining whether or not there are enough residual fungal spores in the sediments to infect native species planted (or seeded) during restoration following dam removal is essential to the success of the restoration effort. 
Additionally, rates of potential natural infection by mycorrhizal fungi from surrounding areas need to be examined. Results of these investigations are crucial for estimating restoration costs and will also have a direct effect on the success or failure of the restoration effort. Previous research suggests that some previous reforestation efforts have failed because no (or few) mycorrhizal fungi infections were present in the planted stock. Two general methods are available for obtaining fungal infections of nursery stock: treatment with duff, and treatment with spores from mycorrhizal truffles. The first offers greater potential fungal diversity for infections while the latter is more easily accomplished and causes less disturbance to sites where the truffles are collected. This project tests whether or not the lake sediments contain extant spores that can inoculate selected plant species that may be used during restoration if the dams are removed.
