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Statistical Testing to Demonstrate Revegetation Success <br />Statistical testing will be used to evaluate achievement of successful revegetation when the parameter <br />sample mean for the reclaimed bond release area is less than 90 percent of the standard. A one - sample t- <br />test will be used in testing the hypothesis that the true mean of the bond release parcel (or monitoring <br />parcel) is indistinguishable from the number representing 90 percent of the standard. One - sample <br />hypothesis testing, as well as the sample adequacy formulas to be used when hypothesis testing is required <br />and when parameter estimation alone is sufficient, will be consistent with the appropriate method or <br />approach outlined in the Division's Rule 4.15.11. Appropriate methods or approaches allowed for in Rule <br />4.15.11 will be coordinated with the Division at the time of revegetation success evaluations. The <br />parameters to be tested for revegetation success are cover, production, species diversity, and woody plant <br />density. <br />Cover. <br />For all reclaimed II -W areas (including the II -W South Extension area), successful revegetation for the <br />parameter of cover will be evaluated as follows. Cover data will be collected from the above five <br />described vegetation types within the designated extended reference area. Included in the average will be <br />data from the Aspen Woodland, Mountain Brush, Steep Mountain Brush, Sagebrush /Snowberry and <br />Western Wheatgrass /Alkali Sagebrush vegetation types. The extent of herbaceous cover in each of the <br />five vegetation types will be represented by the "all-hit" measure of cover in which the full extent of a <br />species cover, whether or not it is overlapped by the canopy of another species is independently assessed. <br />Although the development of trunks, branches, twigs, and leaves of shrubs and trees overarches fairly <br />extensive areas in several of the vegetation types, the herbaceous component is still quite extensive in <br />most, though often in the shade of the woody species. <br />An average of the herbaceous cover of the extended reference area types, weighted by their extent in the <br />premining area affected by mine disturbance (in the II -W permit area including the South Extension area), <br />will be calculated as per the following formula using "all-hit" total herbaceous vegetation cover data: <br />X,v �: 0.90 l(Aa) (Xa) + (Ab)(Xb) + (A mb) (Xsmb) + (AS)(Xs) ± (Apa.) (x,,,,)) <br />where. <br />X,,, = Average all-hit total vegetation cover for revegetated area <br />Aa = Aspen type percentage of the premising surface to be affected by mining (11.0 %) <br />Ab = Mountain Brush type percentage of the premining surface to be affected by <br />mining (34.5 %) <br />Asmb = Steep mountain brush type percentage of the premining surface to be affected <br />TR -70 46 Revised 5/10 <br />