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Results from baseline data collected in 1981: <br />Total cover on the grassland reference azea was 35.5%. The standazd deviation was 8.91. <br />Productivity was measured at 49.11 pounds per acre (5.5 g/MZ). The average stem density was <br />122 stems per 100 MZ (4955 stems per acre) <br />Total cover on the pinyon-juniper reference area was 10.1%. The standard deviation was 2.92. <br />Productivity was 8.82 pounds per acre (0.99 g/MZ). Average stem density was 62 stems per 100 <br />MZ (2546 stems per acre). <br />Based upon the 1981 baseline data the revised vegetation success standards will incorporate the 1981 <br />reference area data to result in the following reclamation success standazds: <br />Revegetation Success Standards: <br />Cover: 22.8 % herbaceous vegetative cover <br />Production: 28.97 ]bs/acre (air dry weight) [3.24 g/MZ] <br />Shrub Density: post mining land use is rangeland and is currently being used for domestic <br />grazing. The mine disturbance area is small, 26 acres, with extensive pinyon- <br />juniper community immediately adjacent. No shrub density requirement is <br />necessary. <br />Species Diversity: At least three perennial grass species, each contributing at least 3%, but not <br />greater than 60% relative cover. At least one of these species will be a cool <br />season grass and the total of warm season grasses will be a minimum of 3% <br />relative cover. <br />III. Results and Discussion: <br />Reclaimed area description <br />The reclaimed area's vegetation consists of mainly two types: grassland and pinyon juniper. The <br />pinyon juniper community has a reduced understory of herbaceous vegeteation, and lower general <br />species diversity. The average annual precipitation in the area is I S inches. In 2002, Colorado <br />experienced a serious drought. 2003 saw a recovery in precipitation levels for the first 6 months of the <br />year. Vegetation on the reclaimed mine site has responded favorably. The type and amount of <br />vegetation varies with differences in slope, exposure and soil depth. <br />Statistical Comparison of Reclaimed and Reference Areas <br />The permit states that vegetative cover reclamation success would be determined using a weighted <br />average of cover collected at two reference areas. Since the reference areas are unable to be located and <br />the pre-mining acreage allotted to each vegetation type is not known, the Division has calculated a cover <br />success standard based upon the 1981 pre-mining data found within the permit. Reclamation vegetation <br />cover standard is 22.8%. <br />