2010-12-17_REVISION - C1981019 (106)

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RULE 2 PERMI received significant sagebrush reduction effort. This reference area was selected to provide target parameters of vegetation that are conducive to Sage Grouse early brood rearing. According to the Colorado Division of Wildlife (CDOW), this is the most important life stage for this taxon that can be provided by lower project area habitats. The radio - telemetry data that had been collected by CDOW was extensively reviewed and concentrations of radio - collared birds during this critical life stage were located from this data. One of the densest concentrations of observations (hence the conclusion that life requisites were being met) and external to the study area, was in the area of the Sage Grouse Target Habitat reference area. Since these birds were extensively using this habitat at this time, it was readily hypothesized that the floral variables, including structural, spatial, and compositional, being provide by this area were optimal for early brooding in Sage Grouse. Floral variables documented from this area could then be utilized to design revegetation efforts to encourage reclamation conducive to this important habitat, and thereby hopefully encourage post - mining recolonization by Sage Grouse. By documenting the characteristics and circumstances provided by this area prior to disturbance, additional reclamation planning capability as well as bond release strategies are afforded for future efforts. A total of 51 plant species were observed in the reference area. No sensitive species were observed. One noxious weed, Canada thistle, was observed in the reference area (Table 2.04.10 -34). The average vegetation cover in the Sage Grouse Target Habitat reference area was 55.2 percent, with 0.4 percent rock, 27.8 percent litter, and 16.6 percent bare ground exposure. Dominant plant species and their ground cover percentage included: western wheatgrass (11.8 percent), snakeweed (8.7 percent), Sandberg bluegrass (7.5 percent), cheatgrass (6.8 percent), mountain big sagebrush (5.6 percent), and low rabbitbrush (3.4 percent). Of the total plant cover, 82 percent (45.2 percent average cover) was due to perennials (excluding noxious weeds). Annuals species contributed 18 percent and noxious weeds contributed 0 percent of the composition. Seven perennial species contributed 3 percent relative cover or composition (3 percent is the typical lower limit for plant diversity bond release evaluations), with four of those species being grasses and three shrubs (Table 2.04.10 -71). The average herbaceous production of the Sage Grouse Habitat reference area was 792 pounds per acre, oven -dry weight, with 76 percent (598 pounds per acre) due to perennials (grasses contributing 363 pounds per acre, forbs contributing 34 pounds per acre, and sub - shrubs contributing 200 pounds per acre) and 24 percent (194 pounds per acre) due to annuals (grasses contributing 164 pounds per acre and forbs contributing 30 pounds per acre). Noxious weeds were not found in any of the sampling quadrants in this reference area (Table 2.04.10 -74). Woody plant density in the reference area was 5,295 woody plants per acre with dominance by holly grape (2,037 plants per acre), low rabbitbrush (1,822 plants per acre), and mountain big sagebrush (1,019 plants per acre). The shrub lifeform accounts for 100 percent of the total. One important parameter that should be noted for this finding is that the density of sagebrush was in the range of 1,000 plants per acre as opposed to the normal sagebrush community density of 4,000 to 5,000 plants per acre (Table 2.04.10- 75). Noxious Weeds Seven noxious weeds were encountered within the Vegetation Study Area and reference areas. In most cases, the density of the noxious weeds was low and only occasionally detected in sufficient quantities during ground cover sampling. There was one instance where the quantities were elevated, which involved Canada thistle which was within the wetland community. It was the most dominant plant 0 recorded. Collom — Rule 2, Page 70 Revision Date: 1/23/09 Revision No.: PR -03