2020-03-24_PERMIT FILE - C1981019A (2)

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RULE 2 PERMITS Based on the supplemental ground cover values above, it would appear that the sagebrush community from the Lower Wilson Study Area (63.1%) is denser than the permit -wide sampling of this community from 1980, 1985, and 1988 once herbaceous vs. total plant cover are factored into the analysis. Most likely, this modest disparity is due to the amount of mesic sagebrush on the Lower Wilson area in comparison to the more dominant xeric sagebrush from the remainder of the current permit area. Aspen Woodland - As indicated on Map 4B, the aspen woodland community within the Study Area occupies 32.63 acres (5.4%) and occurs in only two principal locations. The community exhibits an overstory of aspen (Populus tremuloides) with an understory dominated by herbaceous species and a shrub stratum similar to the mountain shrub community. Of particular note is that much of the aspen overstory in this community is dead or dying owing most likely to the drought that has occurred in Colorado over the past several years. A total of 46 species were observed within the aspen woodland community with a distribution of 10 grasses, 28 forbs, and 8 shrubs or trees. Average ground cover of vegetation (2005) within the study area was 60.7% with 0% rock, 27.7% litter, and 11.6% bare ground exposure. Dominant species included: Mountain snowberry, blue wildrye (Elymus glaucus), stinging nettle (Urtica gracilis), Mountain brome (Bromus marginatus), nettleleaf giant hyssop (Agastache urticifolia), and bluegrass. The number of perennial herbaceous species exhibiting between 3% and 50% relative cover (composition) was determined to be 3 grasses and 2 forbs. As indicated on Table 2.04.10-10, in 1988 the herbaceous plant cover of the aspen woodland community was documented to be 73.0% and production was 772 pounds per acre. Woody plant density for aspen woodland in 1988 was determined to be 6,370 plants per acre. Of this total, aspen contributed 435 trees per acre. Based on the supplemental ground cover values above, it would appear that the aspen woodland community from the Lower Wilson Study Area (60.7%) is comparable to the permit -wide sampling of this community from 1988. Juniper Scrub - As indicated on Map 4B, the juniper scrub community within the Study Area occupies only 12.65 acres (2.1 %) and occurs in only two principal locations, both of which are in the northeast part of the study area. The community exhibits an overstory of Utah juniper (Juniperus osteosperma) with an understory dominated by scattered shrubs (typically mountain big sagebrush) and a thin herbaceous stratum. The juniper scrub type typically occurs on the thinnest, most skeletal soils found in the study area. Occasionally, the community occurs without an overstory of juniper owing to past wildfire. A total of 54 species were observed within the juniper scrub community with a distribution of 11 grasses, 32 forbs, and 11 shrubs or trees. Average ground cover of vegetation (2005) within the study area was 29.2% with 34.2% rock, 12.2% litter, and 24.4% bare ground exposure. Dominant species included: Montana wheatgrass (Agropyron albicans), Mountain big sagebrush, thrifty goldenweed, prairie junegrass, beardless bluebunch wheatgrass, and fewflower buckwheat (Eriogonum pauciorum). The number of perennial herbaceous species exhibiting between 3% and 50% relative cover (composition) was determined to be 3 grasses and 2 forbs. Bottomland - As indicated on Map 4B, the bottomland community within the Study Area occupies 43.96 acres (7.33%) and occurs in two principal locations. The first of these is along the historic Wilson Creek floodplain at the northernmost portion of the mining area portion of the study area. The second is along the disassociated 22 acre haul road crossing area. South Taylor/Lower Wilson — Rule 2. Page 55 Revision Date: 4/7/17 Revision No.: RN -07