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procedures on large units with long slopes that might otherwise lead to excessive <br />"snowmelt" erosion; and 4) assuming 50% shrub establishment success on the acreage <br />that actually receives shrub conducive metrics. <br />Diversity <br />The initial Permit Application addressed Diversity by using the Shannon Weiner Index to <br />measure the distribution of species within the existing premine vegetation community. <br />Over the early years of SMCRA compliance, this procedure was determined to be <br />problematic for this use as a means to evaluate diversity. <br />Colowyo did not feel comfortable using such a complicated Index, but did so because it <br />was the norm at the time to use this method. <br />Since the initial Permit Application, CDRMS regulations have been revised to allow for <br />the use of comparisons of species composition based on cover between the reclaimed <br />area and the undisturbed vegetation. <br />This method of analyzing diversity was applied to the weighted premine herbaceous <br />vegetation cover data originally sampled and summarized in Section 2.04. 10 on Table 2, <br />1980 Herbaceous Cover by Species. <br />A total of four species with a combined contribution to diversity of 43.4% have been <br />chosen to characterize the premine vegetative community diversity standard. <br />The vegetative species with their contribution to diversity are as follows: <br />Species <br />(1) Poa pratenensis <br />(2) Agropyron Smithii <br />(3) Achillea lanulosa <br />(4) Stipa viridula <br />% Contribution to Diversit <br />22.6% <br />10.8% <br />6.7% <br />3.3% <br />43.4% <br />Although Gallium and Lu ip nus caudatus rank reasonably well in the diversity <br />(composition) scale, they were not included in the diversity goals for reclamation. <br />Gallium is an annual, while Lu inus caudatus is considered toxic to livestock and is most <br />likely a product of overgrazing. Colowyo is interested in reclaiming with vegetation <br />species with equal or superior utility for the postmining land use when compared with the <br />utility of the naturally occurring premine vegetation. Neither Gallium nor Lupinus <br />provides any utility towards supporting the premining land use. <br />Three of the species are perennial cool season grasses and one specie is a perennial forb. <br />All of the species are found throughout the premine area on all soil types and moisture <br />regimes. The grass species all provide the qualities for excellent erosion control and <br />livestock use. All four species of vegetation exhibit high utility towards the premine land <br />4.15-24 Revision Date: 3/14/08 <br />Revision No.: TR-72