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West Elk Mine <br />samples at the time of collection in order to evaluate sample size and sample adequacy. In the <br />laboratory, all samples were uniformly dried at 105 C for 24 hours. Oven-dried samples were <br />weighed to the neazest milligram. Mean production estimates were calculated for each species or <br />species group for each vegetation community. <br />Sample adequacy was determined at the time of sampling. The equation used for evaluating sample <br />adequacy is from the OSM guideline, A Statistical Evaluation of Revegetation Success on Coal <br />Lands in the West (Lazson 1980), and is as follows: <br />tZ s1 <br />m= a <br />D <br />where: <br />m = the minimum number of observations needed <br />t = a table value (t distribution) for a given level of confidence <br />s1 = the variance estimate <br />D = the level of accuracy desired for the estimate of the mean <br />1982 Drv Meadow Vegetation Community Resamnlinp <br />After review the 1980 dry meadow data, the OMLR requested changes in the delineation of the dry <br />meadow reference area. The larger dry meadow reference area (Map 44) was then resampled in <br />1982. The dry meadow affected azea was also resampled at the same time. Herbaceous cover, <br />shrub cover, shrub density, and production were all sampled using the same methods used in 1980. <br />Statistically adequate sample sizes were obtained for cover, production, and shrub density for all <br />four areas sampled (Table 24). Sample adequacy calculations for the dry meadow community aze <br />based on the 1982 data. Calculations for the oakbrush community aze based on the 1980 data. <br /> <br />1.04-148 RevrsedNovem6er 1004 PRIO <br />