Mojave Desert, soil, vegetation, sheep, biology, grazing
Animal Sciences | Biology | Ecology and Evolutionary Biology | Environmental Sciences
The effect of domestic sheep grazing on vegetation and soils was measured at two sites in the western Mojave Desert. Although sheep have grazed the Mojave Desert for 50 to 100 years, the effect of grazing on the desert ecosystem is largely unknown.
The results reflect only the short-term effects of grazing because fenced control areas were not available for measurement. The biomass of annuals under creosote bush (Larrea tridentata) decreased 60% under grazing pressure, and the density of annuals decreased 24% and 28% in trampled areas. The shrub cover of burrobush (Ambrosia dumosa) and spiney hop-sage (Grayia spinosa) decreased in a heavily-grazed area. The soil strength in grazed and bedding areas was significantly higher than the soil strength in ungrazed areas, especially in the upper 10 cm of soil. These changes contribute to accelerated erosion, increased stresses on plants, and forage losses for animals.
"This work was supported under Bureau of Land Management Contract No. CA-060-CT8-000041."
Department 1 Awarding Honors Status
Webb, R. H. (1978). Some Effects of Sheep Grazing on Mojave Desert Vegetation and Soils (Undergraduate honors thesis, University of Redlands). Retrieved from https://inspire.redlands.edu/cas_honors/585