Shortgrass rangeland, dominated by blue grama (Bouteloua gracilis), was grazed at 3 intensities light, moderate, and heavy, from 1939 through 1994. In 1992-1994, frequency of occurrence, basal and foliar cover, and biomass at peak standing crop were determined on the remaining pasture at each grazing intensity, and on 3 ungrazed exclosures. Blue grama and buffalograss (Buchloe dactyloides) increased, and western wheatgrass (Pascopyrum smithii) and needle-and-thread (Stipa comata) decreased, as grazing intensity increased. Basal cover and biomass of forbs were lower under grazing than in exclosures, but differences in biomass were not significant. In the same period, plains pricklypear (Opuntia polyacantha) occurred more frequently and covered more area in exclosures and under light grazing than under moderate or heavy grazing. Returns to land, labor, and management were only slightly higher under the optimum stocking rate than under the moderate grazing intensity. The moderate grazing intensity appears to be both profitable and sustainable according to Hart and Ashby.
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