Ventenata (Ventenata dubia) Response to Grazing and Prescribed Fire on the Pacific Northwest Bunchgrass Prairie

The exotic annual grass ventenata (Ventenata dubia L.) is raising concern as it rapidly invades multiple ecosystem types within the United States, including sagebrush steppe, ponderosa pine forests, woodlands, and much of Palouse Pacific Northwest Bunchgrass Prairie (PNB). Despite increasing attention, little known about invasion dynamics ventenata, especially its response to disturbances such grazing fire. In this study, we examined how cattle prescribed fire affect abundance (standing crop, cover, frequency, density) other plant groups on PNB over time using two separate long-term studies established in 2004. first study (Cattle Grazing) looked at 14-yr effect exclusion aboveground biomass cover. Our second (Grazing Prescribed Fire) main interactive effects three sampling periods (2008, 2016, 2018). We documented a 30% increase cover 55% frequency past 15 yr, areas that were not disturbed by or grazing. found only weak evidence increased standing crop when compared with cattle-excluded paddocks, something could be related timing use. There was no burning impacted own. However, some interactions between suggests help reduce grazed livestock. These reinforce important differences invasive winter annuals grasslands clarify need for research focuses primarily relatively new species many ecosystems now inhabits.