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t <br />n m — ( , <br />where: <br />n,„ = minimum sample size <br />s = Sample variance (n -1 degrees of freedom) <br />d = Precision (0.10 for cover and production; 0.15 for woody <br />plant density) <br />x = Sample arithmetic mean <br />t = The (a =.10) t -table value for a 1 tail t -test, n -1 degrees of <br />freedom (infinite degrees of freedom may be used if n >30) <br />n = Sample size <br />During field sampling for cover and production, at least 15 samples (observational units) will be <br />made at each site. Sample adequacy will be tested after 15 samples are taken, using a field <br />laptop computer. Sampling may continue if necessary to reach sample adequacy, or sampling <br />may be terminated before sample adequacy is reached if an alternative statistical method <br />(approved by DRMS) can be used that does note require demonstration of sample adequacy. <br />Alternative procedures will require a minimum of 30 samples, as detailed below. Because dry- <br />weight production data will not be available until samples are dried, sample adequacy will initially <br />be calculated on fresh weights of clipped material, then recalculated laterfor air -dried material and <br />additional field samples will be taken if necessary. <br />Reclaimed area cover and production will be compared to a standard equal to the mean values <br />measured at the reference area by sampling, as described below. Revegetation will be <br />considered "successful' if the mean value for the reclaimed site can be demonstrated to equal or <br />exceed "Q" (Q =90% of the standard). One of the following four methods will be used to compare <br />mean values at reclaimed sites to Q, depending on the mean values and whether sample <br />adequacy was reached during sampling. <br />PR -06 June 2010 2.05.4(2)(e) - 58 <br />