In order to understand whether changes in tree species composition in riparian zones result in significant changes in epiphytic lichens and bryophytes, we need to know how diversity and species composition of these epiphytes vary among riparian forests with different canopy dominants. Understanding the link between riparian canopy type and epiphytic lichen and bryophyte species composition and abundance will facilitate more effective monitoring of potentially at risk species and management of epiphytic lichen and bryophyte communities. We explored the influence of canopy type on the biodiversity of epiphytic lichen and bryophytes by comparing communities between seven different riparian stand types in the Oregon coast range. Our questions of interest included, do communities differ between stand types? and what biotic and/or abiotic factors influence community composition? We found that lichen and bryophyte communities do differ between stand types. Stand basal area in hardwoods, elevation, stand age and floodplain width all appear to be important factors influencing lichen and bryophyte community composition. A transplant experiment performed using four lichen species, including Cetrelia cetrarioides,Hypogymnia inactiva, Lobaria oregana and L. pulmonaria, explored the effect of canopy type on lichen growth. Lichen transplants were placed beneath canopies of Alnus rubra, Acer macrophyllum and Pseudotsuga menziesii in five separate stands. After a year, transplants were collected and growth was calculated. Lichen species were not differentially affected by canopy treatment, though, as a group, lichens experienced inferior health and survival under Acer macrophyllum canopies. Hypogymnia inactiva showed lower mean and median percent growth and health than the other three lichen species. We acknowledge the support of the Cooperative Forest Ecosystem Research (CFER) program.

Key words: bryophytes, ecology, lichens, Oregon coast range, riparian