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1) That within the sample all species in the parent population are represented. <br />2) That the parent population exists as a homogeneous entity. <br />3) That the parent population or collection consists of no more than two species. <br />Pielou (1966) altered the Shannon-Weiner (Weaver) formula to mitigate assumption number 3. His <br />modification is described as follows: <br />H' (s) _ -I i pilogspi; where s =the number of species. <br />However, as such, H'(s) no longer measures diversity as typically defined. Instead, it provides a measure <br />of evenness, or how individuals are portioned among the species in the entire community. <br />Finally, and most importantly, one must be aware that to compare a portion of an undisturbed, natural <br />and relatively stable community (permanent reference site) against what will be a changing community (at <br />least for most of the liability period) by a standard which is subjective in design and intent, is extremely <br />statistically and legally questionable. As it now exists, the diversity index obtained is simply a number <br />that is largely meaningless since it cannot be compared to any known standard for management <br />purposes. <br />It is important at this point to state what we feel is common ground on the issue of diversity between <br />Trapper Mine and the regulatory agencies. <br />• 1. Diversity is ill defined mathematically and controversial. <br />2. The importance of species or life forms should be considered in terms of the end land use. <br />3. A meaningful, acceptable, reproducible standard should be used. <br />4. The standard must be based upon easily obtainable data such as cover, production or density. <br />In light of the described problems, a technique based on more traditional range analysis methods will be <br />used to determine if a diverse plant community is reestablished. Tables 2.3-3 and 2.3-5 list the <br />percentage that each species contributed to the herbaceous aerial cover on range sites A and B in 1980. <br />On range site A, 6 species (4 grasses and 2 (orbs) each comprised greater than 3.0% of that cover (see <br />Table 2.3-3). On range site B, 5 species (4 grasses and 1 forb) each comprised greater than 3.0% of <br />that cover (see Table 2.3-5). Based on the historical predominance of at least 4 grass species and at <br />least 1 forb species on each site as shown in Tables 2.3-3 and 2.3-5, an appropriate diversity standard <br />for evaluating success would be 4 grass species and 1 fort species. <br />n <br />U <br />4-121 <br />Revision: -Te - - <br />Z/ <br />Approved: i8?98