Greenstripping and Grazing for Cheatgrass Webinar
University of Arizona Cooperative Extension Gila County presents: Garden and Country Extension Webinar Series. A Zoom webinar (60-minutes or less) featuring a variety of horticultural and natural resource topics relevant to the environmental conditions and residential concerns of Gila County, Arizona.
Featured Topic: Greenstripping and Grazing for Cheatgrass
Featured Speaker: Dr Lauren M. Porensky. Research Ecologist, Rangeland Resources and Systems Research Unit USDA Agricultural Research Service, Fort Collins, CO. Dr. Porensky is an ecologist interested in plant communities, herbivores, and spatial complexity. Her research focuses on balancing livestock production with conservation and restoration in semi-arid rangelands. Porensky got her PhD at UC Davis working on livestock management and wildlife conservation in central Kenya. She currently investigates the interactive effects of grazing, fire, prairie dogs, and variable weather on plants, livestock, and humans in the northern Great Plains.
Webinar Overview: Millions of hectares in western North America have been negatively impacted by cheatgrass invasion. Post-wildfire restoration generally involves spreading limited resources over extensive areas, and this approach often fails to meet restoration objectives. We investigated an alternative approach that may be able to weaken cheatgrass-fire feedbacks, protect remnant and restored sites, and reduce further invasion by focusing restoration resources in small, spatially strategic locations. We tested multiple methods for creating native greenstrips (fuelbreaks made of native plants), subjected experimental greenstrips to targeted grazing treatments, and monitored seedling densities over two years. At a highly invaded Great Basin site, we found that planting and grazing treatments had strong effects on seedling densities. Plots planted with a doubled seed rate had 50% more seedlings than those planted with an average seed rate. Ungrazed plots had 40% and 90% more seedlings than spring- and fall-grazed plots, respectively. However, results were primarily driven by one planted species (Elymus trachycaulus) which was both highly successful and susceptible to grazing. At a minimally invaded Colorado Plateau site, planted seedling densities were much lower (1-2 per m2) and planting techniques had weaker effects, though seed rate was still an important driver of results. At this site, targeted spring grazing tended to enhance seeded species densities and reduce cheatgrass biomass. Early results suggest that high rate native grass seedings and short-duration spring grazing should be further evaluated as potential tools for addressing cheatgrass invasion, though results may strongly depend on ecosystem context.
Webinar Facilitator: Chris Jones, Extension Agent, University of Arizona Gila County Cooperative Extension
Zoom Link: https://arizona.zoom.us/j/94812511241 Please log in up to 10 minutes prior to the webinar.