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criterion. The table presenting data summaries for total vegetation cover for each area <br />sampled also contains the relative cover by species and a column depicting the numerical <br />ranking of each species by relative cover within the area. <br />2.3 SAMPLE NUMBERS/SAMPLE ADEQUACY <br />For the purposes of this study, total vegetation cover and total herbaceous production <br />sampling were undertaken to sample adequacy with a minimum of fifteen (15) samples for <br />each parameter sampled. Parameter sample adequacy testing occurred at the one-sided 90% <br />confidence level. Comparisons between sample mean parameter values and the revegetation <br />success standard assume that the sample mean value accurately represents the population <br />mean in all cases. <br />The following formula was used for sample adequacy calculations: <br />nmin = <br />(t)2 (S)2 <br />(d Xbar)2 <br />where: nmin = minimum sample size <br />s = sample standard deviation <br />t = the Student's t distribution value at the 90% level (one-sided) <br />d = percent acceptable deviation from the mean (10%) <br />Xbar = sample mean <br />2.4 STATISTICAL ANALYSIS <br />Statistical analysis for the revegetation success criteria of total vegetation cover and total <br />herbaceous production is required if the value of the sample mean from the reclaimed area is <br />less than 90 percent of the value of the final revegetation success criterion for total vegetation <br />cover or total herbaceous production. The 2015 reclaimed area sample means for total <br />vegetation cover and total herbaceous production were greater than the corresponding <br />revegetation success criteria; therefore no statistical analysis was required. A statistical <br />analysis is not required for the evaluation of species composition. <br />2.5 SPECIES IDENTIFICATION AND VERIFICATION <br />Species identification was accomplished in the field through the use of plant identification <br />keys (Harrington, 1954, Weber, 1990; Whitson, 1987; Zimdahl, 1990, Stubbendieck, et al, <br />1995). In cases where plant identification was inconclusive in the field, voucher specimens <br />were pressed for lab identification. <br />Mountain Coal Company, LLC West Elk Mine Page 6 <br />2015 Vegetation Report: Deep Creek, Long Draw, Long Draw Saddle, West Point Road Reclamation Areas <br />