Brown Bag Seminar – Rebecca Bunn – Do mycorrhizal fungi have a role to play after dam removal?
May 24 @ 12:00 pm - 1:00 pm
Do mycorrhizal fungi have a role to play after dam removal? Rebecca Bunn, Western Washington University, Environmental Sciences. Restoration following dam removal projects may depend in part on recovery of arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungal communities, which form symbioses with most land plants and perform important functions belowground. The removal of two dams from the Elwha River (Washington, United States) left 300 ha of dewatered reservoir sediments, an ideal study system for evaluating the availability and function of mycorrhizal fungi for one aspect of ecosystem restoration, revegetation. In a combined observational and greenhouse study using the dual host plant Salix sitchensis (Sitka willow), we focused on three questions: (1) Are mycorrhizal fungal propagules available for plants in recently dewatered reservoir soils? (2) Will reservoir soils inhibit plant growth and mycorrhizal formation? and (3) Will mycorrhizal fungi from mature plant communities benefit host plants growing in reservoir soils, either through increased biomass or nutrient status? This study provides information for restoration managers to evaluate the need for, and potential sources of, mycorrhizal inoculum in recently dewatered reservoirs.