February 15, 2011: Effectiveness of post-fire seeding and herbicide treatments to battle cheatgrass in Zion National Park

Presenter: Andrea Thode (Northern Arizona University)

Fine fuels from non-native, annual brome grasses have overcome native plants across much of Zion Canyon in Zion National Park. This invasion threatens the single road that provides access into—and escape from—the canyon, creating a threat to human life should a large wildfire occur there. In addition, native riparian plant communities in Zion Canyon have been degraded by non-native plants, and recurrent fire caused by annual grasses could further reduce native plant diversity. Results from this study suggest that burning can have a more lasting effect than annual mowing in reducing fine fuel loads, extending the period between repeated maintenance treatments. When burning is coupled with fall herbicide application, added control can extend the maintenance interval even further through reduction of brome grass density.