FY2017The Integrated Rangeland Fire Management Strategy Actionable Science Plan places a high priority on assessing control measures for invasive annual grasses, which provide fuel for rangeland fire and impede restoration of desirable perennials. Weed-suppressive strains of the bacterium Psuedomonas fluoresens (P.f.) are an emerging but yet untested tool for selectively reducing these annual grasses. P.f. may suppress annuals for approximately 2-5 years, bridging the short-term action of herbicides and long-term resistance provided as native bunchgrasses recover. In 2015-2016, the USGS responded to a request from the Idaho sage grouse action group to establish a series of field-based experiments to assess the efficacy of P.f. on public and private lands in Idaho. These experiments will describe where, when, and why P.f. has desired or unintended impacts on exotic and native plants. This project represents a continuation of the field-based experiments begun in 2015 and 2016 to examine the impacts of P.f. application on invasive annual grasses as well as native plants. The effects of application rates, timing, and other management variables will be assessed to identify the conditions needed to achieve desired management results. Funding for this project was provided by the Great Basin Landscape Conservation Cooperative, Bureau of Land Management and the U.S. Department of Agriculture.
