Location: Great Basin Rangelands ResearchTitle: Perennial grass dominance: creating a resilient plant community in an exotic annual grass invaded rangeland Author
Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/7/2013
Publication Date: 7/22/2013
Citation: Harmon, D.N., Clements, C.D. 2013. Perennial grass dominance: creating a resilient plant community in an exotic annual grass invaded rangeland [abstract]. Soil and Water Conservation Society International meeting. 68:48. Interpretive Summary:
Technical Abstract: Millions of hectares of western rangelands have been invaded by the exotic and invasive annual grass, cheatgrass (Bromus tectorum). Cheatgrass provides a fine-textured, early maturing fuel that has increased the chance, rate, spread and season of wildfire to public and private lands throughout the Great Basin from xeric salt desert shrub communities up into the more mesic pinion-juniper woodland communities. These wildfires have resulted in controversy of just how to rehabilitate these various affected habitats and the management options available to resource managers and land owners. Rehabilitation requires controlling cheatgrass, and more importantly facilitating the development of a sustainable plant community. Through our research, we have formulated general strategies based on decades of rangeland rehabilitation efforts. While it is a work in progress, it provides the greatest chance for success in the 30cm (12inch) or less precipitation zones of the northern Nevada region of the Great Basin. The concepts are based on successional theory and agronomic principles using an active management approach. Historical wildfire frequencies in the big sagebrush/bunchgrass communities of the Intermountain West are estimated at every 60-100 years. With the introduction and subsequent invasion of cheatgrass, these frequencies have increased to every 5-10 years, simply too short a period of time to allow succession to progress. Our research has centered on the establishment of long-lived perennial grasses to suppress cheatgrass densities and fuel loads in an effort to restore or rehabilitate successional processes and allow a resilient shrub/bunchgrass community to develop over time. The use of native and introduced plant materials are tested from germination to emergence and followed for multiple years to record establishment. Cheatgrass seed bank and above-ground densities are recorded annually to provide resource managers and land owners with on-the-ground realities of those perennial grass species that performed the best in terms of establishment as well as cheatgrass suppression. This paper will present on-the-ground results where an integrated approach of mechanical and herbicidal weed control practices were implemented along with plant material testing to best identify those species that have the best inherent potential to germinate, emerge and compete in the cheatgrass invaded habitats. In conclusion, our long term research has demonstrated that implementing an integrated approach using grazing management, herbicide and mechanical control and fall seeding efforts with the most effective seeded species, can protect and repair the landscape from the damage of cheatgrass invasion.