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D. Revegetation Success Standazds <br />Prior to initial disturbance at Colowyo, Colorado State University and the Soil Conservation Service <br />Upper Colorado Plant Materials Center conducted studies, in cooperation with Colowyo, to <br />determine appropriate seed sources, species composition and revegetation practices to ensure <br />reclamation success at the mine site. Results ofthe studies conducted by Colorado State University <br />are included in Exhibit 10, Volume IV, of the permit. No final report has been issued from the SCS <br />Plant Materials Center. <br />Methods for evaluating vegetative success are found in Section 4.15 of the original Permit volumes, <br />and in Section 2.(14.10 and 4.15 of Volume 12, submitted in association with PR-2. As part of this <br />process, two reference areas have been established for the determination of reclamation success. One <br />reference area represents the sagebrush community while the other represents the mountain shrub <br />community. Cover data was collected by measuring five random points along 100-foot long <br />transects. A ten-point frame was used to measure each of the five points. Production values were <br />measured by clipping 30cm x 30cm plots at each of the five points along the transect used to measure <br />cover. 1976 data reflects air dry weight while 1988 data was measured with 60cm x 60cm plots with <br />plant biomass being oven dried prior to weighing. <br />Based on herbaceous cover and productivity from the sampled reference areas, the revegetation <br />success criteria are as follows: <br />Herbaceous cover will be at least 90 percent of the cover measured in the reference area with <br />a 90 percent statistical confidence level. Herbaceous productivity for revegetated azeas will <br />be no less than 90 percent as productive as the associated reference azea with a 90 percent <br />statistical confidence level. <br />Herbaceous cover and production success for the "original" permit area disturbances and for the <br />relatively limitedl acreage of disturbance projected for the Lower Wilson disturbance (120 acres <br />approximate) will be based on acreage weighted comparisons, using the sagebrush and mountain <br />shrub reference areas, in accordance with Rule 4.15.7(4)(b), as previously approved. <br />For the proposed South Taylor expansion area disturbance (azea enclosed by "Tie-in Boundary For <br />Post Mining Topography" on Map 23A), herbaceous production and cover success testing will be <br />based solely on comparison to the sagebrush reference area, pursuant to Rule 4.15.7(3)(b)(iii) and <br />4.15.7(4)(c). Arguments for the use of the latter approach for the proposed South Taylor expansion <br />area are presented under the Justification for Reference Area Selection-Sagebrush Reference Area, <br />narrative of Volume 12, Section 2.04.10, of the application. Relevant portion of the narrative notes <br />that: <br />...the sagebrush-grassland ecotype is the main ecological community that will be <br />targeted by reclamation planning for the disturbed South Taylor project area for two <br />principal reasons. First, efforts to establish Mountain Shrub andAspen revegetated <br />Proposed Decision and Findings of Compliance 4 May 2007 <br />Permit Revision 02 Page 56 <br />