Density, cover and biomass of spotted knapweed was examined on Idaho fescue, bluebunch wheatgrass dominated sites in outside of Bozeman, Montana. This study was designed to examine the effects of grazing on spotted knapweed establishment. Idaho fescue plants within 1 m² plots were clipped at four levels (0, 30, 60 and 90% defoliation), two seasons (spring and summer) and three frequencies (1, 2 and 3 at 14-day interval) over a period of three years for a total of 24 treatments replicated 4 times at 2 sites classified as Idaho fescue and bluebunch wheatgrass habitat types. Density of spotted knapweed was measured by counting the number of rosettes and flowering stems within a 10 by 50 cm plot. Cover of spotted knapweed and grass cover were estimated within the plot frame using 6 cover classes. Biomass of knapweed and grass was harvested within a 0.5 m² hoop in late July the year following simulated grazing treatments.
Citations and enhanced abstracts for journals articles and documents focused on rangeland ecology and management. RSIS is a collaboration between Montana State University, University of Idaho, and University of Wyoming.