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Composition of the shrub stratum is similar to Mountain Shrub 1 communi- • ties. Other species occasionally occurring in this stratum are antelope bit- terbrush (Purshia tridentata), mountain mahogany, and broom snakeweed. The herbaceous stratum is markedly different. Grasses are scattered, with a pre- dominance of bunchgrasses. Commonly encountered grasses include Indian ricegrass (Oryzopsis hymenoides), prairie junegrass (Koeleria cristata), blue bunch wheatgrass (Agropyron spicatum), and Great Basin wildrye (Elymus cinereus). Ephemeral forbs are scattered and of approximately the same com- position as found with sagebrush-grassland communities. Canopy coverage of this community is signficantly less than that exhibited by Mountain Shrub 1 communities. This is directly correlated to the poorer soil and moisture conditions. Depending on the dominant species in each variation of this type, cover values range as follows: gambel oak - 10 to 40 percent; • sagebrush - 10 to 40 percent; snowberry - 10 to 15 percent; bunchgrass - 5 to 10 percent; and forbs - 5 to 10 percent. Total cover values range from 0 to 90 percent, with an average of about 65 percent. Shrub heights of 3 to 4 feet in this community are significantly less than in Mountain Shrub 1. Potential productivity is substantially less than Mountain Shrub 1 commun- ities. A range of 600 to 1400 pounds per acre is estimated from SCS descrip- tions for the corresponding range site in excellent condition. Aspen communities (covering approximately 20 percent of the area) tend to occur on north-facing, moderate-to-steep slopes and along more mesic drainage bottoms. Soils are a very deep, dark, fine loamy pachic cryoboroll exhibiting poor development. . This type is dominated by quaking aspen (Populus tremuloides) with two main variations in the understory. The first variant is a community of taller aspen - 127 - (Rev. 5/86)