INTEGRATED INVASIVE SPECIES CONTROL, REVEGETATION, AND ASSESSMENT OF GREAT BASIN RANGELANDS
Location: Great Basin Rangelands Research
Title: Research to practical use: on-the-ground success
Submitted to: Rangelands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 14, 2012
Publication Date: August 15, 2012
Citation: Clements, D.D., Young, J.A., Harmon, D.N., Weltz, M.A. 2012. Research to practical use: on-the-ground success. Rangelands. 34(4):54-60.
Interpretive Summary: The USDA, Agricultural Research Service, Great Basin Rangelands Research Unit, services a large area that runs from south-central Nevada to the Oregon border and from northeastern California to the Utah border. Stakeholders have requested our assistance in addressing a number of issues throughout this vast array of landscapes. This paper addresses three examples: 1) tall whitetop (Lepidium latifolium) control and rehabilitation, 2) cheatgrass (Bromus tectorum) suppression in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) communities, and 3) restoration of antelope bitterbrush (Purshia tridentata) communities in which we present our efforts to 1) research the problem at hand, 2) deliver practical on-the-ground practices to minimize or eliminate the problem, and 3) improve sustainable agricultural practices. Tall whitetop was controlled with the combination of herbicide and plant material suppression. The selective herbicide 2, 4-D was sprayed in late May during the flowering stage at 2.2 kg/ha rate, followed by the seeding of a long-lived perennial grass, tall wheatgrass (Elytrigia elongata) at 10.3 kg/ha rate in October and then another herbicide application of 2, 4-D at 1.1 kg/ha the following spring after the perennial grass seedlings had reached the 3+ leaf stage. By the 6th year the site was returned back to production agriculture at a cost of $40.30/ha. In our efforts to control cheatgrass and test plant materials that have the inherent potential to compete in these harsh environments, we researched and tested 1) timing of restoration/revegetation seeding applications, 2) mechanical control, 3) herbicide control, and 4) plant material testing. Seeding the first fall following the wildfire was significantly (P = 0.05) more successful at recruiting seedlings of seeded species than seeding after this initial open window. Mechanical (dising) and herbicides (i.e. Plateau®) both reduced cheatgrass seed bank densities and increased seeded species densities. Crested wheatgrass (Agropyron cristatum) performed the best as this species experienced 9.9/m² compared to species such as squirreltail (Elymus elymoides), 1.4/m². We tested seeding and transplanting methodologies of antelope bitterbrush in an effort to restore this key browse species. Our best results came from our efforts of seeding this species at 3.4 kg/ha rate using a no-till drill. Our efforts yielded 3,175 shrubs/ha compared to using the traditional rangeland drill which yielded 1,015 shrubs/ha. Both densities are excellent as the adjacent unburned habitat has a density of 202 antelope bitterbrush shrubs/ha. This seeding effort cost $30.38/ha compared to transplanting, which experienced about 15% success, and would cost over $3,000/ha to get similar results. Complete methodologies, treatments and results are presented.
In 2011, the Society for Range Management held its national meeting in Billings, Montana. A symposium was put together to focus on “Agency Success Stories”, we were invited to present some of our successes. We presented three examples of our efforts to 1) research the problem at hand, 2) deliver practical on-the-ground practices to minimize or eliminate the problem, and 3) improve sustainable agricultural practices. Tall whitetop (Lepidium latifolium) is an exotic weed that has invaded native hay meadows, agronomic fields and wetlands throughout the western United States. We tested the control of tall whitetop through 1) mechanical (discing), 2) chemical (herbicides) and 3) biological (goats and plant material) treatments. The application of 2, 4-D (2.2 kg/ha) in early May followed by seeding a long-lived perennial grass, tall wheatgrass (Elytrigia elongata) the following October, at 10.3 kg/ha rate, was very successful. In addition we sprayed 2, 4-D at 1.1 kg/ha the following spring after the tall wheatgrass seedlings had reached the 3+ leaf stage. This knocked back tall whitetop further and released critical resources for the perennial grass seedlings to establish. In two years the site was dominated by tall wheatgrass, tall whitetop suppression was complete in four years and the site was returned back to production agriculture by the sixth year. Cheatgrass (Bromus tectorum), native to Eurasia, is a highly invasive annual grass that has invaded millions of hectares of rangelands throughout the Intermountain West and Columbia Basin. Cheatgrass has revolutionized secondary succession by providing a fine-textured, early-maturing fuel that increases the chance, rate, spread and season of wildfires. We researched 1) the timing of seeding application, 2) mechanical control methods, 3) herbicide control treatment and 4) plant material testing in an effort to improve restoration/revegetation efforts and decrease cheatgrass densities and fuel loads. Seeding the first fall following the wildfire resulted in significantly (P = 0.05) more seeded species seedling recruitment than waiting past this open window of opportunity. Discing significantly (P = 0.05) reduced the cheatgrass seed bank and increased the establishment of seeded species by reducing cheatgrass competition. Herbicides such as Plateau® and Landmark® were excellent tools at decreasing cheatgrass seed production and reducing cheatgrass seed bank densities which also allowed seeded species to experience increased establishment. The establishment of native and introduced plant species is reported, but the take home message is species like crested wheatgrass (Agropyron cristatum), 9.6/m², experienced significantly (P = 0.01) more seedling establishment than other species tested such as squirrelltail (Elymus elymoides), 1.3/m². Antelope bitterbrush (Purshia tridentata) is a critical browse species to native ungulates and domestic livestock. Many existing stands are either old and decadent or have been lost to wildfires. We researched seeding and transplanting methodologies that would improve the restoration of this key browse species. Seeding antelope bitterbrush with a no-till drill, where terrain permits such equipment, resulted in 3,175 shrubs/ha compared to the traditional rangeland drill,1,015/ha, when seeding at 3.4 kg/ha. Transplanting experienced an average of 15% success and was simply too expensive compared to mechanical seeding technology. Exact methods, treatments, results and costs are presented.