Prior to Euro-American settlement, the Willamette Valley contained extensive grasslands including upland prairie, wet prairie and oak-pine savanna. Those habitats have become increasingly rare and, because of their high biodiversity value, are being targeted for conservation and restoration. We conducted an experiment at the Howard Buford Recreation Area near Eugene, Oregon, to test the effects of prescribed fire on the composition and structure of a prairie plant community, and, more broadly to investigate how ecosystem dynamics affect the community's invasion by exotic species.
Nine macroplots were burned in the spring of 2003 and nine macroplots were left as unburned controls. Both pre-burn and post-burn plant data were taken from all plots. Preliminary results indicate that 1) the burn benefited native forbs over exotic forbs, but had no significant effects on native or exotic grasses. Fuel consumption and gopher disturbance also had significant effects on the plant community. 2) the effects of burning on restoring native plant diversity are highly dependent on differences in soils across the site. We are characterizing seasonal soil moisture and nutrient mineralization dynamics, as well as other soil geochemical characteristics. Our ultimate goal is to provide a mechanistic framework to understand the spatial characteristics and best management methods for native plant diversity in Willamette Valley prairies.
Collaborators: Bitty Roy (UO) and Scott Bridgham (UO)Click on arrow below for more images: