Laserfiche WebLink
• Statistical Testing to Demonstrate Revegetation Success <br />Statistical testing will be used when the parameter sample mean for the reclaimed bond release area is <br />less than 90 percent of the standazd. Aone-sample t-test will be used in testing the hypothesis that <br />the true mean of the bond release parcel (or monitoring pazcel) is indistinguishable from the number <br />representing 90 percent of the standard. One-sample hypothesis testing, as well as-the sample <br />adequacy formulas to be used when hypothesis testing is required and when parameter estimation <br />alone is suffident, will be consistent with the Division's Guideline Regazding Selected Coal Mine <br />Bond Release Issues (April, 1995) or current regulations and guidelines in effect at the time of bond <br />release application. <br />The parameters to be tested for revegetation success aze cover, production, woody plant density, and <br />speaes diversity. <br />Cover <br />For the shrub grassland type in the reclaimed mine azea, successful revegetation for the parameter of <br />• cover will be evaluated as follows. Cover data will be collected from the above Fouz described <br />vegetation types within the designated extended reference azea. Included in the average will be data <br />from the Aspen Woodland, Mountain Brush, Steep Mountain Brush, and Sagebrush/Snowberry <br />vegetation types. The cover success for the concentrated shrub and rtee establishment sites will be <br />included in the sampling of the wider universe. The extent of herbaceous covet in each of the four <br />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 independendy <br />assessed. Although the development of trunks, branches, twigs, and leaves of shrubs and trees <br />overarches fairly extensive areas in several of the vegetation types, the herbaceous component is still <br />quite extensive in most, though often in the shade of the woody species. <br />An average of the all-hit herbaceous cover of the extended reference area types, weighted by their <br />extent in the prem+~+ng azea to be affected by mine disturbance will be calculated as pez the following <br />formula using "all-hit" total herbaceous vegetation cover data: <br />X,n.2 0.90 ((A,) (x,) + (Ab)(xb) + (`ismb) \.'smb) + (+\T)(~')) <br />• where: - <br />X.~, Average all-hit total vegetation cover for revegetated azea <br />PR-02 35 Revised 01/06 <br />