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According to SCS range site descriptions and analysis of the baseline vegetation data, shrub • <br />densities on the site are estimated to be higher than optimum. These densities may be two to <br />four times higher than the allowable amounts for optimum range condition. Additionally, the <br />northern portion of the permit area was burned in the last 10 to 20 years, which has <br />encouraged extensive sucltering in the mixed brush type and an increase in mountain snowbetry <br />in the sagebrush type (see Tab 10, Appendix 10-9). Aspen stands have also been affected by <br />livestock grazing, pazticularly sheep grazing. Many of the aspen stands in the permit area have <br />somewhat depauperate understory vegetation and a distinct lack of regeneration. Existing <br />stands are dominated by mature and decadent trees. These observations are consistent with <br />those in other azeas of the west (DeByle and Winokur, 1985). <br />While diminished range condition can be attributed to livestock grazing, it is further <br />compounded by the ecological characteristics of the woody plant communities and the <br />livestock and wildlife utilization patterns occurring in these communities. The woody <br />component in these communities readily increases when the herbaceous component is reduced <br />in vigor of eliminated. <br />Cattle and sheep are not carried on the permit area during the winter months, thus eliminating • <br />any winter browsing of woody species by livestock. Livestock grazing begins in late May or <br />early June. During the summer months, both cattle and sheep center their foraging preferences <br />on the more nutritious and palatable herbaceous species. While some browsing of the woody <br />species by livestock does OCNT during the summer, it is generally limited because of the <br />availability of succulent and more palatable species. In all, the woody component is favored in <br />these native stands. <br />In addition to livestock grazing, wildlife data for the permit azea (see Tab tl, Wildlife Survey) <br />indicates that utilization of browse by big game is not excessive. The highest use of browse by <br />big game is expected to occur during the winter months. During the summer months, use of <br />browse will drop and big game will concentrate on the more nutritious and palatable <br />herbaceous species. Again, the woody component may be favored. <br />The appazent light use of browse by big game and livestock, coupled with the ability of the <br />woody species to increase under livestock grazing, has resulted in higher woody plant densities. <br />Tisdale and Hironaka (1981), in an extensive review of the literature on the sagebrush grassland • <br />region, found that overall use of sagebrush by wildlife and livestock combined was generally <br />light. This resulted in minimal impact to sagebrush, especially in relation to the associated <br />2 <br />