RUCHTY, ANDREA* AND BRUCE MCCUNE. Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331. - Influence of canopy type on the biodiversity of epiphytic lichens and bryophytes in riparian forests.
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