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• Where: <br />z = the number of standard deviations (both ways from the mean) encompassing 75% of <br />the normal distribution (= 1.15; see Rohlf and Sokal 1969, Table P) <br />s = standard deviation (n-1) <br />The standard is the lower bound of the central 75% of the distribution of overall species density in <br />the reference areas. Mathematically this is: <br />Mean reference area species density (no. of species per 100 sq.m.) - 1.15 s <br />The standard is based on a weighted average as done with cover and production. <br />Note that this test addresses total species density, not just native species density (see D) below). <br />Noxious weeds are omitted. The point of addressing total species density, including annual / <br />biennial species and introduced species, is that the total species density is arguably a strong <br />indication of the existence of niche spaces that could eventually be occupied by the native forb <br />and woody plant species typical of the pre-mining plant communities. <br />The final step for the Test B assessment is comparison of the mean total species density of the <br />reclaimed area to the reference area-derived standard number (above). If the reclaimed area <br />mean exceeds the standard, the Test B is passed. <br />Alternative Test C): Assessment of the Distribution of Species Density Among Lifeforms <br />in Comparison to the Reference Areas <br />This test relates to the distribution of the presence of species among the various lifeforms in <br />comparison to the reference areas. This standard uses the Motyka similarity index to assess the <br />resemblance of the distribution of species density by lifeform of the reclamation vegetation to that <br />of the reference areas. Because the average internal resemblance (i.e. between-sample <br />similarity) of applicable reference areas for species density data is often in the range of 70%, the <br />proposed standard is 63% (0.9 x 70%). (The assessment of internal similarity was performed on <br />data from the extended reference areas (Sagebrush, Mountain Brush, and Aspen) from the <br />nearby Seneca II-W Mine. The Seneca II-W extended reference areas extend across sections of <br />landscape more comparable in dimension to the Seneca II reclaimed areas than are the <br />comparatively small Seneca II reference areas. Thus, they are thought to be more indicative of <br />pre-mining inter-stand community diversity). <br />6