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A classification such as this would make the similarity comparison <br />more species oriented while allowing WECC the flexibility to not <br />have to recreate exact reference species associations. In its <br />present form, the classification only compares physical community <br />structure. Because the emphasis of the species diversity <br />comparison as borne out by Rule 4.15.8(5), lies in species rather <br />than structural diversity, the growth form classification should be <br />modified. <br />B. WECC makes the statement that "... the index of similarity is <br />more appropriate than the Shannon-Wiener function in evaluating <br />reclamation success because it simultaneously accounts for <br />diversity plus commonality of each component." WECC has used <br />examples which indicate that this statement is true when the <br />similarity index is calculated using a species specific (e .g. <br />Agropyron smithii in reference area vs. Agropyron smithii in <br />rec acme area, etc. for each species) comparison. or instance, <br />if comparison of two areas results in a high species specific <br />similarity index, there is a good chance that their diversity <br />indices will be similar. However, WECC has not demonstrated that <br />high growth form based similarity indices indicate a high diversity <br />index simi'farily. Making the present growth form comparisons more <br />specific may sufficiently address this issue. <br />C. A third reason to make the growth form categories more specific <br />involves the issue of how many of the recently selected categories <br />will actually apply during the comparison. Table 1 lists eleven <br />(11) growth form categories that may be used in determining <br />similarity between reference and revegetated areas. However, only <br />about 6-7 categories will be applicable to the mixed shrub <br />revegetated areas while it is expected that 5-6 will be applicable <br />to the dry meadow reclaimed areas. Table 10 lists the growth form <br />categories that applied to the Dry Meadow and Wet Shrub affected <br />area herbaceous layers. The subshrub, annual grass, xerophytic <br />shrub, cactus, merophytic tree, and conifer categories did not <br />apply to the dry meadow affected herbaceous layer. The same <br />categories, with the exception of that of subshrubs, did not apply <br />to the herbaceous layer of the mixed shrub area. Obviously these <br />categories are valuable to consider in the event that they will <br />show up. For instance, it is especially important to have the <br />category "annual grass"; a high percentage of this category over <br />several years would indicate that reclamation was not as successful <br />as hoped. However, as the classification stands, not enough <br />categories will be represented by non-zero numbers in either the <br />reclaimed or reference areas for the comparison to be significant. <br />D. On the third page of Exhibit 4.6.1 .A, WECC states, "the <br />growth-forms represented here make it possible to identify problems <br />such as weed invasion (Annual Forb and Annual Grass)." However, <br />some of the worst weed species are biannuals or perennials and <br />therefore would not be represented in either of the two categories <br />