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mountain loam range sRe is similar to the sagebrush type. The deteriorated range condition is reflected in a <br />higher density of shrubs at the expense of the herbaceous component. According to SCS range site • <br />descriptions and analysis of regional baseline vegetation dais, shrub tlensities may be two to four times <br />higher than the allowable amounts for optimum range condition. Aspen stands have also been affected by <br />livestock grazing, particulady sheep grazing. The aspen stands in the permit area are characterized by a <br />poor understory vegetation and a distinct ladle of regeneration. Eldsting stands are dominated by mature and <br />decadent trees. These observations are consistent with those in other areas of the west (DeByle and <br />Winokur, 1985). <br />While diminished range cendition can be attributed to livestock grazing, d is further compounded by the <br />ecological characteristics of the woody plant communities and the livestodk and big game utilization patterns <br />occurring in these communities. The woody component in these communities readiy increases when the <br />herbaceous component is reduced in vigor or eliminated. The mountain brush type represents well <br />established dorsal communities that readily exploit opportunities for expansion in the presence of <br />perturbations to herbakxwus vegetation such as overgrazing. Similady, snowberry and sagebrush will <br />okxupy niches formerty occupied by herbaceous species. Tisdale antl Hironaka (1981), in an extensive <br />review of the literature on the sagebrush grassland region, found overall use of sagebrush by wildlife and <br />livestock combined was generally light. This resulted in minimal impact to sagebrush, especalty in relation <br />to the associated herbakx;ous component. They also found sagebrush stands have a strong competitive <br />edge once herbaceous competition is reduced. <br />Cattle and sheep do not graze in the permR area during the winter months, thus eliminating any winter • <br />browsing of woody species by livestock. Livestock grazing usually begins in mid to late June. During the <br />summer months, both cattle and sheep center their foraging preferences on the more nutritious and <br />palatable herbaceous species. While some browsing of the woody species by livestock does occur during <br />the summer, it is generaly limked because of the availability of more palatable herbaceous spaces. This <br />grazing selection has favored the woody component in these native stands. <br />The highest use of browse by big game is expelled to occur dudng the winter months when browse spades <br />are dormant or in the spring before significant herbaceous production. During the summer months, use of <br />browse will drop somewhat and big game will increase use of the more nutritious and palatable herbakx;ous <br />spekies. This will again favor the woody component. <br />The use patterns of browse by big game, coupled with the ability of the woody spades to increase under <br />livestock grazing, has resulted in higher woody plant densities. Based on personal observations, <br />discussions with SCS range conservationists from the Craig and Steamboat Springs offices, the State SCS <br />range conservationist in Denver, and plant ecologists from area mines, the somewhat degraded plant <br />community characteristics for the mixed brush and sagebrush types found on the Seneca II Mine are <br />common in northwestern Colorado. <br />Wildl'sfe Habitat and Utilization of Native Rangeland. The Senece II permit area is loceted in a region that is • <br />utilized by a variety of wildlife spaces. The three pdmary untlisWrbed vegetation types present (sagebrush, <br />mixed brush, aspen) provide food and cover habitat for many of the wildlife spades year-round. Of particular <br />TR-37 132 Revised 04/05 <br />