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Submitted to: Rangelands
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/19/2017 Publication Date: 12/7/2017 Citation: Clements, D.D., Harmon, D.N., Blank, R.R., Weltz, M.A. 2017. Improving seeding success on cheatgrass-infested rangelands in Northern Nevada. Rangelands. 39(6):174-181. Interpretive Summary: The accidental introduction and subsequent invasion of cheatgrass (Bromus tectorum L.) onto millions of hectares of Great Basin rangelands has led to the conversion of former big sagebrush (Artemisia tridentata Nutt.)/bunchgrass communities to cheatgrass dominance. Native to Europe, central Asia and northern Africa, cheatgrass was accidentally introduced to North America where it was first identified in Pennsylvania around 1861, believed to be in contaminated wheat, and later identified in northern Nevada in 1902 where it spread rapidly throughout big sagebrush rangelands. Aldo Leopold recognized more than a half century ago how impossible it is to protect wildlife habitat from wildfire because of the presence of cheatgrass. This invasive annual grass truncates secondary succession by largely inhibiting the establishment of perennial seedlings through competition for moisture. The ability of resource managers and land owners to restore or rehabilitate cheatgrass infested rangelands is extremely challenging. The best known method to suppress cheatgrass densities and associated fuels is through the establishment of long-lived perennial grasses. In this paper we will describe our experiences in establishing long-lived perennial grasses on cheatgrass infested rangelands with the ultimate goal of reducing cheatgrass densities and associated fuels and wildfire risks in an effort to allow succession to take place and improve grazing and wildlife resources. Technical Abstract: Invasion of alien plant species influences all phases of wildland research in the Great Basin. The accidental introduction and subsequent invasion of cheatgrass (Bromus tectorum L.) onto millions of hectares of Great Basin rangelands has led to the conversion of former big sagebrush (Artemisia tridentata Nutt.)/bunchgrass communities to cheatgrass dominance. Cheatgrass has revolutionized secondary succession in xeric sagebrush plant communities in the entire Intermountain Area by providing a fine textured, early maturing fuel that increases the chance, rate, spread and season of wildfires. The ability of resource managers and land owners to restore or rehabilitate cheatgrass infested rangelands is extremely challenging. The best known method to suppress cheatgrass densities and associated fuels is through the establishment of long-lived perennial grasses. Testing the hypthesis that seeding the 1st fall following a big sagebrush wildlfire would be more successful thatn seeding the 2nd fall resulted in the recording of crested wheatgrass plots seeded the first fall following the wildfire (2006) averaged an establishment of 9.6/m² compared to the 2007 seeded plots, 3.9/m². Using a disc and fallow method to control cheatgrass and improve seeded species success yuielded that un-disced cheatgrass plots averaged more than 1,350 cheatgrass seeds/m², while plots receiving our April/May discing application averaged less than 250 cheatgrass seeds/m², 82% reduction in cheatgrass seed bank densities. This reduction significantly increased the success of seeding long-lived perennial grasses. Using herbicides to control cheatgrass and improve seeding success was also investigated. We recorded cheatgrass control during the fallow year of 95.6% in the Plateau treated plots and 98.7% in the Landmark plots. The establishment of long-lived perennial grasses at both locations reduced above-ground cheatgrass densities by more than 93%. An integrated approach of using natural events, mechanical and chemical treatments allows resource managers and land owners the option of aggressively controlling and reducing cheatgrass densities and associated wildfire risks. |
