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UJ III. INTERRELATIONSHIPS BETWEEN GRAZING MANAGEMENT, RANGELAND CJI CONDITION, AND SALINITY o (it Since publication of the 1977 Salinity Status Report (3), investigations have continued concerning grazing by livestock and its effects on salin- ity. Conclusions reached in the 1977 report were: - Disturbance and movement of saline soils, through increased storm runoff, will increase rangelands contribution to the salinity of perennial stream systems. - Increases in the area of ground covered by live vegetation and surface litter (dead plant material), reduced compaction of the surface few inches of soil, and increased friability (soil tilth) of the soil surface will increase infiltration and reduce runoff, hence reduce saline water yield from saline lands. , , ""'" Based on these. assumptions, it was theorized that proper management of livestock grazing, with the intent of stabilizing saline soils, would reduce salinity. Further analysis and a continued search of published results of studies dealing with hydrologic responses to grazing are outlined in the following sections. Unregulated grazing by herbivores (domestic, feral, and wildlife) is considered to be a significant factor in causing increases of salinity in overland or surface runoff from saline wildlands. Grazing, especially by domestic livestock, is the most extensive use of these federally, state, and privately controlled lands. Meehan and Platts (32) state that rangeland management is closely interrelated with water management, observing that "the combined effects of geology, climate, geomorphology, soil, vegetation, and water runoff often result in unstable stream conditions in the natural state. When land uses place additional stress on aquatic habitats, damage usually occurs." Water management and maintenance. of stable stream channels, therefore, are closely i.nter- related to control of salinity from surface runoff on rangelands, The BLM admi n i sters about 150 mi 11 i on acres of graz i ng 1 ands in the western United States (10, 25). Of these, 135 million acres are produc- ing livestock forage below their potential. The Comptroller General reported that allotment management plans, outlining systematic grazing schedules, did not exist for 107 million acres of public lands (10). Land deterioration was principally attributed to "poorly managed live- stock grazing." The report cited a 1976 address by the BLM Director to a group of Nevada pub 1 i c 1 and users, in whi chhe stated that unauthor~ ized grazing by numbers of livestock in excess of those allowed by BLM "was the largest contributor to the state's deteriorated rangelands." It is true, however, that giant strides have been made in improving range conditions over the years since the Taylor Gra'zing Act was passed in 3 'f .' <.