Spotted knapweed control methods affect native plant establishment in a Michigan prairie restoration.
College of Liberal Arts and Sciences
Restoration efforts are hindered by invasive plant species. Moreover, the effects of control methods on the establishment of native plant species are often unknown. To determine effective treatment combinations for positively influencing native plant establishment while reducing spotted knapweed, we seeded with native forbs and grasses and tested 12 different treatments including combinations of an initial site preparation (mowing, mowing + clopyralid, or mowing + glyphosate), annual knapweed hand pulling, and controlled burning on a knapweed-infested site. We found that native species can establish without intensive knapweed control, growing on plots retaining greater than 50% knapweed cover. Pulling increased native species establishment in addition to reducing knapweed cover. Glyphosate application resulted in high non-native forb cover, while pulling and clopyralid application favored non-native grasses, which will provide fuel for burning and may help prevent knapweed resurgence. Both the pulling and clopyralid treatments have the most improved trajectories toward native-dominated communities.
Stewardship Network Conference
East Lansing, MI
MacDonald, Neil W.; Martin, Laurelin M.; and Brown, Tami E., "Spotted knapweed control methods affect native plant establishment in a Michigan prairie restoration." (2014). Faculty Scholarly Dissemination Grants. 843.