The Effects of Prescribed Burning on Wet Prairie Lichen Communities
Emily A. Holt
Paul M. Severns
The Willamette Valley wet prairie is a rare grassland ecosystem located in western Oregon. Fern Ridge Research Natural Area protects approximately one quarter of this unique ecosystem on public lands. Currently, the Research Natural Area (RNA) is burned to minimize woody plant encroachment and to optimize the response of rare vascular plant species. The rarity of the wet prairie habitat and the anomalous occurrence of the boreal-arctic lichen, Cladina mitis (Sandst.) Hustich, has sparked concern about lichen response to fire in this habitat. We sampled terricolous wet prairie lichen communities in burned and unburned habitats to quantify the potential effects of fire on lichens. We found evidence that burning reduced overall lichen abundance and diversity in the wet prairie. Prescribed burning may benefit vascular plants, but is harmful to terricolous lichen communities. The current practice of maintaining unburned refuges for C. mitis conserves all aspects of the wet prairie lichen community by providing a source for colonizing individuals and preserves the unique wet prairie populations of C. mitis.
A Community Participatory Project to Restore a Native Grassland
Wade D. Albrecht
Joyce Maschinski
Amy Mracna
Sheila Murray
This unique project invited community members to test sustainable techniques for restoring a weed-infested field to a native grassland community. In a cultivated Bromus inermis grassland at The Arboretum at Flagstaff, Flagstaff, Arizona, we randomly assigned 144 plots to weed removal and recovery treatments. The experimental design had 12 replicate plots assigned to organic herbicide, weed barrier fabric, manual removal, or control for the weed removal factor; it had seeding, plugging, or no action for the recovery factor. College, middle and high school students, and community members collected and propagated native seed, implemented restoration treatments, collected plant community data, and learned methods for implementing restoration in their own backyards. We quantified percent cover of smooth brome, other exotics, and native species cover and richness. Although no treatment completely removed B. inermis, manual removal was the most effective treatment for significantly reducing B. inermis, while significantly increasing native species richness and cover. Weed barrier fabric followed as the second most effective method, and organic herbicide was ineffective. After three months, neither seeding nor plugging significantly affected native cover. A longer response time and irrigation may improve recoverytreatment success.
Widespread community support made this project possible. Post-activity evaluations indicated that students gained an appreciation and working knowledge of restoration. The goal to engage citizens in a project that will become a locally adapted seed resource for future restoration projects has shown promise in its first year, but will require more input before a weed-free native seed resource is realized.