2011-06-02_APPLICATION CORRESPONDENCE - C2010089 (12)

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• • specific limits of disturbance and corresponding impacts to different vegetation types could not be calculated. Therefore, the discussion of revegetation success standards is presented only in a general sense in this section and the specific details are found in the discussion regarding Rule 4.15.7. Reclamation. The disturbance to all areas corresponding to the Reclamation vegetation type (REC) shown on Map 2.04.10 -1, Permit Area Vegetation Map will be reclaimed according to the currently approved land use of dryland pasture. The currently approved Dryland Pasture Reference Area is located on the west side of the Hopkins Field Airport. No changes are proposed beyond what the DRMS has already approved for this vegetation type in the existing NH2 Mine Permit. Since DRMS has already approved the proposed revegetation success standards for this vegetation type, no changes are being proposed for this vegetation type. All areas shown on Map 2.04.10 -1, Permit Area Vegetation Map as corresponding to REC -IMIP, located on the parcel to the west of the Garvey house will be reclaimed as Intensively Managed Irrigated Pasture and the revegetation success standards for this parcel as well as all other Intensively Managed Irrigated Pasture parcels which will be disturbed by mining are found in the discussion of that vegetation type which follows. Big Sagebrush. Disturbance to all lands corresponding to the Big Sagebrush vegetation type (SB) shown on Map 2.04.10 -1, Permit Area Vegetation Map will be reclaimed according to the currently approved revegetation success standard for dryland pasture as the DRMS has currently approved for the existing Big Sagebrush areas found within the existing NH2 Mine. The currently approved Dryland Pasture Reference Area is located on the west side of the Hopkins Field Airport. No changes are proposed beyond what the DRMS has already approved for this vegetation type as currently approved in the existing NH2 Mine Permit. Upon comparing the proposed Big Sagebrush disturbance areas with the existing Dryland Pasture Reference area, it can be determined that the calculated t value for total plant cover and forage production were determined to be equal 3.5796 and 2.8988, respectively. The corresponding t values were determined to equal 2.048 and 1.986, respectively. Since both the t values for both plant cover and forage production, exceed the corresponding t values, it can be concluded that the total plant cover and forage production values between these two sites is statistically different. A major reason for these differences is largely attributable to the fact that upon comparison of Appendix Table 2.04.10 -6, Big Sagebrush - Plant Cover with Appendix Table 2.04.10 -24, Dryland Pasture Reference Area - Plant Cover, it can be readily observed that the total plant cover value is 26.60 percent for Big Sagebrush and 16.39 percent for the Dryland Pasture Reference Area. Shrubs and subshrubs contributed 12.47 percent of the total plant cover for the Big Sagebrush and only 8.00 percent of the total cover for the Dryland Pasture Reference Area. Annuals and biennials contributed 8.40 percent of the total cover for Big Sagebrush type and only 0.56 of the total cover for the Dryland Pasture Reference Area. Section 2.04.10 Page 30 April 2011