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2.2.3 Total Herbaceous Production <br /> Total herbaceous production was estimated by the harvest method. One herbaceous <br /> production plot was located and randomly oriented at the origin of each cover transect. <br /> Herbaceous production plots were 0.50 square meters (m2) in area. All current year above <br /> ground live herbaceous plant biomass was clipped within the 0.50 in quadrat. Production <br /> material was air dried until weights varied by no more than 0.1g. <br /> 2.2.4 Species Composition <br /> Species composition information was derived from quantitative vegetation cover data. <br /> Relative cover information provided a basis for evaluation of the importance of each <br /> encountered plant species and lifeform, and for comparison to the final revegetation success <br /> 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. <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 /> (t)2 (s)2 <br /> nmin = (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 /> Mountain Coal Company,LLC West Elk Mine Page 5 <br /> 2019 Vegetation Report:West Bench,Sylvester Gulch,Shaft Canyon Road,and Saddle Road Reclamation Areas <br />