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ARS Home » Pacific West Area » Burns, Oregon » Range and Meadow Forage Management Research » Research » Publications at this Location » Publication #388554
Research Project: Restoration and Conservation of Great Basin Ecosystems

Location: Range and Meadow Forage Management Research

Title: Managing medusahead using dormant season grazing in the northern Great Basin

Author
item PRICE, WILLIAM - University Of Idaho
item HULET, APRIL - University Of Idaho
item JENSEN, K - University Of Idaho
item STRAND, EVA - University Of Idaho
item Boyd, Chad
item Davies, Kirk
item JOHNSON, DUSTIN - Oregon State University
item PERRYMAN, BARRY - University Of Nevada
item DI, YANMING - Oregon State University
item ARISPE, SERGIO - Oregon State University

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2023
Publication Date: 7/20/2023
Citation: Price, W.J., Hulet, A., Jensen, K.S., Strand, E.K., Boyd, C.S., Davies, K.W., Johnson, D.D., Perryman, B.L., Di, Y., Arispe, S.A. 2023. Managing medusahead using dormant season grazing in the northern Great Basin. Rangeland and Ecology Management. 90:146-156. https://doi.org/10.1016/j.rama.2023.04.006.
DOI: https://doi.org/10.1016/j.rama.2023.04.006

Interpretive Summary: Medusahead is an invasive annual grass that infests sagebrush rangeland in the western US; it reduces livestock forage availability and dependability, degrades wildlife habitat, and increases wildfire probability. Our research assessed dormant season grazing impacts on vegetation dynamics in medusahead-invaded plant communities in southeast Oregon sagebrush steppe over a two-year period. We found no significant differences in cover or density of annual and perennial grasses between treatments and years. Our results suggest that two years may not be adequate time for dormant season grazing treatments to be effective in reducing the abundance of medusahead, and that after two years of treatments, dormant season grazing does not have a detrimental effect on perennial vegetation.

Technical Abstract: The invasive annual grass, medusahead, infests rangelands throughout the West, from the Columbia Plateau to the California Annual Grasslands and the Great Basin. Dominating secondary succession in the sagebrush steppe, medusahead can degrade the habitat of threatened species such as the greater sage-grouse. This research explores the potential of dormant season grazing as an applied management strategy to reduce the negative impacts of medusahead while promoting recovery of perennial vegetation at the landscape scale. In particular, it assessed grazing with four treatments from 2018 to 2020: traditional grazing (May–October), dormant season grazing (October–February), traditional'+'dormant season grazing (May–February), and no grazing. After 2 yr of grazing treatments, biomass, density, cover, and fuel continuity did not differ between treatments (P > 0.05). However, biomass measurements were significantly different between years, which is likely due to greater than normal precipitation in 2019 and 2020. Between 2018 and 2019, annual grass biomass increased by 81% (666–1 212 kg ha-1) and perennial grass biomass increased by 165% (118–313 kg ha-1). Litter biomass decreased by approximately 15% in every year since 2018 (2 374, 2 012, and 1 678 kg ha-1 in 2018–2020). There were not significant differences in cover or density of annual and perennial grasses between treatments and years. Our results indicate that 2 yr may not be adequate time for dormant season grazing treatments to be effective in reducing the abundance of medusahead and that after 2 yr of treatments, dormant season grazing does not have a detrimental effect on perennial vegetation.