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more complex calculations associated with a two- sample t -test (CDMG 2003 proposed rules <br />• revisions) would be undertaken. <br />Cover will be addressed in hypothesis testing as percent absolute first hit herbaceous vegetation <br />cover as adjusted for excessive contribution by annual / biennial species (CDMG 1995, Guidelines <br />Regarding Selected Coal Mine Bond Release Issues, 1 (IN�A(4)). Cover from reclaimed area samples <br />will be addressed as total percent first hit herbaceous cover. Cover from reference area sampling will <br />be first hit herbaceous cover DOUBLED (see explanation of cover performance standard as per <br />permit, above). <br />Hypothesis testing for production will be based on total annual herbaceous production also adjusted <br />for excessive contribution of annual / biennial species. Herbaceous cover or production values used <br />in hypothesis testing will exclude values for species present on the Routt County Prohibited or <br />Restricted Noxious list or that are listed as noxious by the State of Colorado (Colorado Dept. of <br />Agric.,Division of Plant Industry, Tide 35, Article 5.5, 101 -119, Lists A and B of Rules as replaced <br />2003). <br />Species Diversity <br />Species diversity suitable to support the approved port- mining land uses of rangeland and wildlife habitat will be judged <br />using the following four (4) test; success would be demonstrated by passing the first (A) and at least two of the <br />remaining three (B, C, and D). <br />• Mandatory Test A): No Overwhelming Dominant <br />No single plant species may exceed 60% relative cover. <br />• Alternative Test B): Total Species Density Test <br />It is proposed that this overall reclamation diversity standard be judged based on the species density <br />• values observed along with cover sampling in 100 sq.m. sample plots. It is further proposed that the <br />species density numbers be subjected to sample adequacy assessment in the usual manner. <br />For purpose of establishing the range of species density within the reference areas, the 75% range of <br />variation would be established as: <br />zxs <br />Where: <br />z = the number of standard deviations (both ways from the mean) encompassing 75% of the <br />normal distribution (= 1.15; see Rohlf and Sokal 1969, Table P) <br />s = standard deviation (n -1) <br />The standard would be the point at which the central 75% of the distribution of overall species <br />density in the reference areas begins. Mathematically this would be: <br />Mean reference area species density (no. of species per 100 sq.m.) - 1.15 s <br />The standard would be Gored on a weighted average as done with cover and production. In words the selected standard <br />is the midpoint (in terms of probability distribution) of the lower half of the range of variation of the reference areas. <br />ESCO Associates 13 -13 -8 TR40 * 03106 <br />