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1 ' II. METHODS - ---- -------- - TIl1'II1VG ' Field investigation was undertaken during the period July 5-July 8, 1993. This time period coincided with anthesis and maximum development of the majority of plant species found in both the native vegetation community (Upland Sagebrush Reference ' Area) and the two areas to be evaluated for revegetation establishment (Area 1 and Area 2). The timing of vegetation sampling was discussed with Messrs. Dan Mathews, Harry Ranney, and Tony Waldron of the Colorado Division of Minerals and Geology, and they concurred with the sampling dates. Mr. Waldron was also present during the field sampling of a portion of Area 2. ' SAMPLING DESIGN ' Prior to initiation of field work, the permit document, and applicable maps, and aerial photographs were reviewed to evaluate topography, reclamation timing, seed mixes, revegetation methods, and applicable revegetation standards at both areas. ' A 1:4800 scale (1"=400') map of the reclaimed mine site (permit document Exhibit 22-1, Postmine Vegetation Map: Nucla Mine) was used to delineate the three sampling areas. On the map, a Cartesian coordinate grid (50x50 feet for the reference area, ' 100x100 feet for Areas l and 2) was established for each of the three areas. Sample sites were established using random methods. A minimum of twenty random sample ' locations were initially established for each area. Sample sites were located in the field through compass triangulation and pacing from known landmarks. Since Areas 1 and 2 wntained reclaimed and revegetated areas of differing ages, each different age stand ' was measured on the map to determine aerial extent. Samples within Areas 1 and 2 were taken to proportionally represent these different age stands. Further, Area 2 ' sampling took into account the proportion of untopsoiled area within Area 2 and sampled accordingly. Figure 4 illustrates the location of the Upland Sagebrush Reference Area, Area 1, Area 2, and sample point locations. FIELD SAMPLING Vegetation cover was estimated by the use of the point-intercept method. An ocular point frame (ESCO Associates) was used to minimize instrument error and maximize precision and observer accuracy. Due to the small size of the Upland Sagebrush Reference Area (approximately 2.5 acres) transects were 25 meters in length, with a sample data point collected at 0.5 meter intervals along the transect. In Areas 1 and 2 transects were 50 meters in length, with a sample data point collected at 1.0 meter intervals along the transect. Transect direction was established randomly.