2010-05-07_PERMIT FILE - C2009087A (4)

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spicata), Nelson needlegrass (Acnatherum nelsonii), oniongrass (Bromelica bulbosa), mountain • bromegrass (Ceratochloa polyantha), and slender wheatgrass. Introduced perennial cool season grasses were very sparse, providing only 0.8 percent measurable cover. The most frequently present was smooth brome which occurred in about 40 percent of sampled stands. Native annual (and biennial) forbs comprised 0.6 percent of total vegetation cover. The most commonly occurring of these species were linearleaf collomia (Collomia linearis) and baby blue -eyes (Collinsia parviflora). These plants occur on the very widespread soil castings resulting from the burrowing of northern pocket gophers which find the friable organic rich soils of the mountain brush (as well as the sagebrush) areas to be very suitable. Total vegetation cover in the portion of the Mountain Brush affected area vegetation type (Table 1) was 72.6 percent, while standing dead, litter, bare soil, and rock were 3.2, 16.5, 6.7 and 1.0 percents, respectively. By comparison, in the Seneca II Mountain Brush Reference area (described below and documented in Table 11), total vegetation cover was 81.5 percent, while standing dead, litter, bare soil, and rock were 1.4, 11.1, 6.1 and 0.0 percents, respectively. Species density in the Mountain Brush affected areas was 36.1 species per 100 sq. m., while in the reference area, it was 35.3 species per 100 sq. m. • Herbaceous biomass production averaged 740.5 pounds oven -dry per acre in the affected area (Table 2) and 770.9 pounds oven -dry per acre in the reference area (Table 12). Similar to the understory of aspen areas, the herbaceous biomass production of the mountain brush sites is limited by shading and other forms of competition with the extensive woody cover, so even under favorable moisture conditions, the total remains rather modest. SAGEBRUSH Photographs 19 through 20 (Affected) and 52 through 56 (Reference) Cover in this vegetation type (affected) is also dominated by native shrubs which account for 40.1 percent of total vegetation cover (Table 3). The major two contributors by far are big sagebrush and mountain snowberry, with occasional important additions from silver sagebrush (Seriphidium canum). Saskatoon serviceberry and Douglas rabbitbrush (Chrysothamnus viscidiflorus) are fairly commonly encountered in the type but account for little cover. Native perennial cool season grasses are the second most abundant lifeform, comprising 28.5 percent of total vegetation cover. The largest contributions to this total came from Agassiz bluegrass, needle- and - thread (Hesperostipa comata) and Nelson needlegrass, but substantial portions came from slender • wheatgrass, western wheatgrass and sun sedge (Carex pensylvanica ssp. heliophila). Native 16