Cheatgrass (Bromus tectorum) is an invasive annual grass common in several semiarid plant communities in the western U.S. B. tectorum presence increases fire frequency and size, reducing species diversity, and leading to annual species-dominated systems with inconsistent livestock forage potential and degraded wildlife habitat value. Most efforts to manage B. tectorum-dominated rangelands have focused on controlling the plant itself rather than addressing the causes of vegetation change. An alternative approach, ecologically-based invasive plant management (EBIPM), identifies treatments that can alter factors associated with the causes of succession, leading to a more desirable vegetation state. This study utilized the EBIPM framework to design a large-scale demonstration project, which implemented a series of manipulation treatments (mowing, prescribed fire, imazapic herbicide, and seeding with perennial species) to suppress B. tectorum and promote desirable species. The treatments were implemented at two semiarid shrubland sites in northwestern Utah. Treatments were evaluated by measuring resident vegetation cover, density, aboveground biomass, and litter and soil seed banks. Herbicide was most effective in reducing B. tectorum cover, density, and biomass, while fire was effective in reducing seed density in the litter seed bank. Treatment interactions were rarely significant; however, by combining fire and herbicide, increased B. tectorum control was achieved. Seedlings of seeded perennial grasses emerged in all treatments; however, establishment by the end of the first growing season was greatest in treatments involving fire. The results of this study indicate that using a decision-making framework to select a series of treatments that alter the causes of succession can improve the management of B. tectroum-dominated rangelands.
| Identifer | oai:union.ndltd.org:UTAHS/oai:digitalcommons.usu.edu:etd-2019 |
| Date | 01 August 2011 |
| Creators | Fowers, Beth |
| Publisher | DigitalCommons@USU |
| Source Sets | Utah State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | All Graduate Theses and Dissertations |
| Rights | Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact Andrew Wesolek (andrew.wesolek@usu.edu). |
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