The influence of three years of controlled sheep grazing on spotted knapweed (Centaurea maculosa) infestations in an Idaho fescue (Festuca idahoensis) dominated site in southwestern Montana was examined. Three 0.1 ha grazing enclosures were set up within a pasture that had historically been grazed by horses. Density of spotted knapweed, arrowleaf balsamroot, and Idaho fescue were measured before and after the grazing period. Bare ground and litter cover were also estimated. Soil core samples to test spotted knapweed seedbank were taken before and after the study. Plots were grazed in mid-June (5-7 days), in July (2-6 days), and in early September (1-2 days). Utilization ranged from heavy to severe (75-95%).
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.