Integrated approach to cheatgrass suppression on great basin rangelands

Authors: Clements, Darin - Charlie; Harmon, Daniel - Dan; Weltz, Mark; WHITE, JEFF - Newmont Mining Corporation

Submitted to: International Rangeland Congress
Publication Type: Proceedings
Publication Acceptance Date: 1/5/2016
Publication Date: 7/18/2016
Citation: Clements, D.D., Harmon, D.N., Weltz, M.A., White, J. 2016. Integrated approach to cheatgrass suppression on great basin rangelands. In: Proceedings of the X International Rangeland Congress, July 18-22, 2016, Saskaton, Saskatchewan, Canada. p. 793-794.

Interpretive Summary: Cheatgrass (Bromus tectorum), native to central Eurasia, is a highly invasive annual grass that has invaded millions of hectares of rangelands throughout the Intermountain West. Cheatgrass has revolutionized secondary succession by providing a fine-textured, early-maturing fuel that increases the chance, rate, spread, and season of wildfires. Habitats that are reported to have historically burned every 60-110 years are now burning every 5-10 years, simply to short of a period to allow critical browse species to return. The best known method to suppress cheatgrass is through the establishment of long-lived perennial grasses. Innovative and aggressive weed control practices must be applied in most rangeland restoration/rehabilitation efforts to decrease cheatgrass seed bank and above-ground densities for any hope to establish perennial grasses. This paper describes an integrated approach at suppressing cheatgrass through proper seeding methodologies following wildfires as well as active weed control practices using mechanical and herbicide treatments which can decrease cheatgrass-seeded species competition at the seedling stage. These aggressive approaches are critical if land managers are going to turn the tide of critical grazing and wildlife habitats being converted to cheatgrass dominance.

Technical Abstract: Cheatgrass (Bromus tectorum), native to central Eurasia, is a highly invasive annual grass that has invaded millions of hectares of rangelands throughout the Intermountain West. Cheatgrass has revolutionized secondary succession by providing a fine-textured, early-maturing fuel that increases the chance, rate, spread, and season of wildfires (Young et al. 1987). Research estimates the presence of cheatgrass has reduced the interval between wildfires from an estimated 60–110 years down to 5 years. This paper provides information as to the importance of active weed control practices using effective herbicides, which yielded as much as 98.7% control of cheatgrass, as well as mechanical treatments that decreased cheatgrass seed bank densities by 72%. Using natural wildfire occurrences with proper seeding methodologies and selected seed species can result in improved effectiveness in rehabilitating cheatgrass infested rangelands. An integrated approach of controlling cheatgrass seed bank and above-ground densities using natural events as well as mechanical and chemical treatments can yield very favorable results, especially when in conjunction with proper seeding methodologies. The ability of resource and land managers to apply these techniques in rangeland restoration/rehabilitation efforts can vastly improve the future of degraded Great Basin plant communities by decreasing cheatgrass fuel loads and associated catastrophic wildfires.