In a multi-year study funded by the US Fish and Wildlife Service, we are testing the effect of various management activities on the endangered prairie flower, Willamette daisy.  This spring, we introduced four populations of this species for experimental habitat treatments.  Treatments include ecological burns, selective use of herbicides, mowing, and grazing with sheep.

The sheep were placed in the plots October 25.  Each plot will be grazed for 12 to 24 hours – until there is no more food remaining in the plots.  Pre-treatment monitoring found that while most native species (including Willamette daisy) were dormant, several species of exotic grasses had greened up.  It is our intent that these grasses will be controlled by the fall grazing.

One of the challenges in sustaining populations of rare species is a lack of information on how to manage these species’ habitat.  Applying treatments in the wrong season and/or with the wrong frequency can have detrimental impacts on native prairie species.  Several recent studies have documented that ecological burns, thatch removal, and selective use of herbicides can be useful techniques to maintain prairie habitats and discourage invasive species.  Unfortunately, we currently have little information on how these treatments affect rare species, whose populations are generally too small and fragile to use in experiments.  The information from this experiment will be critical for managing populations of this species in the future.

If you have any questions about this project, please contact Andrea Thorpe at andrea@appliedeco.org or 541-753-3099 ext. 401.