2013-10-02_PERMIT FILE - C1981019A (3)

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RULE 2 PERMITS r.... _ ~ __v_ _.~ • ST-SRA is substantially elevated over all other compazable sagebrush data sets from the area, but most importantly, the values are 25% and 50% higher than the surrounding South Taylor Study Area during the same year for cover and production, respectively. Some of this difference with data sets from other years can be explained by an analysis of precipitation. However, the strong differences between the ST-SRA and the study azea reduce the defensibility of this reference area as an appropriate compazator. Seventh, the sagebrush-grassland ecotype is the main ecological community that will be targeted by reclamation planning for the disturbed South Taylor project area for two principal reasons. First, efforts to establish Mountain Shrub and Aspen revegetated communities in Northwest Colorado within the timeframe of the liability period have met with repeated and well-documented failures. Second, replacement of habitats conducive to Sage Grouse is of far greater importance to the CDOW than any other wildlife species group. In this regard, the C-SRA provides a far better example of the long-term desirable vegetation structure and composition that is more closely tied to the habitat requisites of Sage Grouse. Given the mobility of most wildlife taxa (including Sage Grouse), there is sufficient Mountain Shrub habitat within proximity to planned disturbances to meet a majority of perceived needs of other wildlife populations including elk herds. Eighth, a healthy stand of perennial grasses (with or without occasional stands of sagebrush) has been shown to be the most effective erosion control on young reclaimed landscapes. With fast growing roots to absorb moisture and -arge above-ground biomass to intercept precipitation, gasses are more effective in stabilizing barren soil than the more slow-growing deciduous shrubs of the Mountain Shrub community. A few deep-rooted and long-lived sagebrush plants provide diversity and long-term stability to reclamation provided there is a healthy component of grasses and forbs in the understory to stabilize the soil surfaces between individual shrubs. The shrub to perennial grass ratio on the C-SRA (27% • sagebrush to 50% perennial grass, forb and sub-shrub composition) is a reasonable target for long-term mature reclamation with respect to erosional stability. (An ideal target for a mature community conducive to Sage Grouse brooding habitat will have a lower component of sagebrush in the composition - more in the range of 10%.) MOUNTAIN SHRUB REFERENCE AREA Colowyo will use the originally established Colowyo Mountain Shrub Reference Area (C-MSRA-1980) for future determinations of revegetation success for the Lower Wilson disturbance areas as well as the original permitted disturbances. ColoHyo has determined to use this reference area instead of the "Hamer established" South Taylor Mountain Shrub Reference Area (ST-MSRA) for five reasons as follows. First, the C-MSRA is readily accessible (located above Taylor Creek immediately west of Colowyo's West Pit operations) and should remain accessible during the life-of-mining. The ST-MSRA is located high in the rugged terrain even further south than the ST-SRA where access may be intermittently or permanently interrupted by mine-related activity. Second, the C-MSRA has been measured more frequently over the past several years and therefore, presents a more extensive historic data-base. In addition, since the C-MSRA is currently used for bond release success compazisons at the Colowyo Mine and proposed for use as a reference area for the Collom Project, it would simplify and streamline future bond release sampling efforts at all these projects if a single mountain shrub reference area was used. Third, based on statistical testing per current CDRMS guidelines, the ST-MSRA is not comparable to the South Taylor Study Area for ground cover (see Table 2.04.10-27) but is eligible as a reference area only • because values are higher than those found in the study area. The sampling adequacy and equivalency procedures used by Hamer in 1984 were more liberal for such evaluations. South Taylor/Lower Wilson- Aule 2, Page 80 Revision Date: 3/30/07 Revision No.: PR-02