Rangeland Conservation Practices

We conducted a 5-year study on the impact of nutrients, depending on stream and season. grazing on stream-channel bare ground and erosion, and a © CSA 3-year study of cattle-trail erosion on intermittent stream channels draining grazed oak (Quercus)-woodland 450. Correlations of stocking with the cryptogamic soil watersheds. These studies were conducted on the San crust of a semi-arid rangeland in southwest Joaquin Experimental Range in Madera County, California, Queensland. USA. While the concentration of cattle along stream banks Hodgkins, I. W. and Rogers, R. W. during the dry season resulted in a significant increase in Australian Journal of Ecology 22(4): 425-431. (1997) bare ground, we were unable to detect stream bank erosion NAL Call #: QH540.A8; ISSN: 0307-692X resulting from any of the grazing treatments applied. Descriptors: biodiversity/ community structure/ cryptogamic However, we did find that cattle trails are an important soil crust: community, condition/ dung density/ hoof impact/ mode of sediment transport into stream channels. While semi arid rangeland: habitat/ water supply cattle trails are common on grazed rangeland, excessive Abstract: The soil crust community from a sub-tropical trailing often indicates that stock watering points are too far grassland in southwest Queensland was found to include apart. 34 taxa with cyanobacteria, other algae, lichens, fungi, © CAB International/CABI Publishing mosses and liverworts represented. Cyanobacteria and liverworts were the major components of the cryptogamic 449. Consequences of livestock grazing on water cover. This is a significant component of the biodiversity of quality and benthic algal biomass in a Canadian natural the region. Changes in the structure of this community were grassland plateau. significantly correlated with distance from a linear water Scrimgeour, G. J. and Kendall, S. supply (bore drain) and with dung density. It was concluded Environmental Management 29(6): 824-844. (2002) that hoof impact by grazing stock had measurably affected NAL Call #: HC79.E5E5; ISSN: 0364-152X the cryptogamic community even under a moderate Descriptors: phosphorus/ watersheds/ biomass/ stocking policy. This research suggests that management concentration/ nitrogen/ nutrients/ grazing/ water quality/ for sustainable use of low-nutrient rangelands should grasslands/ communities/ livestock/ streams/ environmental include consideration of soil crust condition. impact/ algae/ agricultural pollution/ nutrient concentrations/ © The Thomson Corporation man-induced effects/ phytobenthos/ rivers/ riparian vegetation/ nutrients (mineral)/ environmental effects/ 451. Debunking the myth of overgrazing and soil agricultural runoff/ environmental quality/ Canada, Alberta, erosion. Cypress Hills/ Canada, Alberta/ livestock grazing Rowntree, K.; Duma, M.; Kakembo, V.; and Thornes, J. Abstract: The effects of livestock grazing on selected Land Degradation and Development 15(3): 203-214. (2004) riparian and stream attributes, water chemistry, and algal NAL Call #: S622.L26; ISSN: 1085-3278 biomass were investigated over a two-year period using Descriptors: carrying capacity/ communal rangeland/ livestock enclosures and by completing stream surveys in ecology/ equilibrium and non equilibrium theory/ grazing the Cypress Hills grassland plateau, Alberta, Canada. impact/ land use change/ myth debunking/ overgrazing/ Livestock enclosure experiments, partially replicated in soil erosion three streams, comprised four treatments: (1) early season Abstract: What is overgrazing? Does it cause soil erosion? livestock grazing (June-August), (2) late season livestock The recent debate from the ecological literature is reviewed grazing (August-September), (3) all season grazing (Juneas background to the debate on overgrazing and soil September), and (4) livestock absent controls. Livestock erosion. This debate stresses the need to view dryland grazing significantly decreased streambank stability, grazing systems as dynamic ecosystems driven more by biomass of riparian vegetation, and the extent to which rainfall events than by livestock numbers. The case for soil aquatic vegetation covered the stream channels compared erosion is then examined. Two case studies from with livestock-absent controls. Water quality comparisons communal rangelands in the Eastern Cape, South Africa, indicated significant differences among the four livestock have cast doubts on the conventional wisdom that grazing treatments in Battle and Graburn creeks but not in overgrazing leads to soil erosion. The first, a study of