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_ occurred in two separate aspen stands which faced north (Figure 1). The <br />• aspen reference area comprised portions of two aspen stands which faced <br />northeast. <br />Because of favorable moisture relations, a wide variety of shrub, grass <br />and forb species were present under the aspen canopy. Shrubs were not <br />numerous in the aspen vegetation, but several different species were <br />presetn. Bluegrasses (Poa spp.), foothills brome (Bromus polyanthus) <br />and blue wide rye (Elymus lag ucus) were the most abundant grasses. <br />Common forbs in this type were nettleleaf giant hyssop (Agastache <br />urticifolia) , violet (viola sp.) , meadowrue (Thalictrum fendleri) , sweet <br />anise (Osmorthiza occidentalis), aspen peavine (Lathyrus levcanthus) and <br />numerous others. <br />3.3.1 Herbaceous Biomass <br />Fifteen lm2 plots were clipped to estimate standing crop biomass in both <br />the aspen mine area and the reference area. In both areas, bluegrass had <br />the highest mean biomass (Table A.1, A.2). Other important species .were <br />foothills brome and nettle Urtica diolca. It was necessary to group several <br />forb species under a single "forbs" heading since numerous species were <br />present in small quantities in each plot. This category was large for this <br />community type, averaging about 10-11 g!m=. Separately weighing all forb <br />species was infeasible due to the low weights of minor species. <br />Mean total biomass on the mine area was 81.6 g/m2 ± 28.1 and on the <br />reference area it was 90.0 g/m= # 37.4. Since mean biomass on the ref- <br />erence area was slightly greater than on the mine area, the reference area <br />was considered acceptable. Both areas were sampled adequately within the <br />appropriate statistical requirements. <br />3.3.2 Herbaceous Cover <br />Tables A.3 and A.4 contain results of the point-frequence estimates of <br />herbaceous cover for the mine and reference areas, respectively. Four <br />transects were measured on the mine rea and three were measured in the <br />reference area. On the mine area, total vegetaion cover ranged from <br />•. 44-55$ and on the reference area it ranged from 50-54$. Percentage litter <br />cover was high in both areas, as it ranged from 30=9-53$; correspond- <br />