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SPECIES DIVERSITY AND COMPOSITION <br />With regard to Mandatory Test A, that no single species comprise greater than 60% relative cover in <br />2012 BRB PSCM -2, Table H -1 shows that the most abundant single species (alfalfa) was 18.11% relative <br />first -hit cover, below the 60% threshold of concern. <br />With regard to Alternative Test B, the Total Species Density test the following is calculated for 2012 BRB <br />PSCM -2 (Table H -2): <br />Mean Species density (Area - weighted) in the two reference areas = 28.45 species per 100 sq.m. <br />Probability- adjusted density standard: <br />Mean Reference Area Species Density —1.15 s = 28.45 —1.15 (4.07) = 23.77 <br />Mean total species density in the 2012 BRB PSCM -2 = 23.83 <br />A classic t -test of the assertion that the 2012 BRB PSCM -2 Total Species Density is indistinguishable <br />from 90% of the standard is as follows: <br />tcalc — <br />Probability adjusted density standard — x <br />(i ) <br />t �35 23.77 — 23.83 — —0.059 <br />talc = 6.04 <br />) <br />Critical t (a = 0.1) = 1.307 <br />Hence Mandatory Test A is passed. <br />Since critical t tabie = 1.307 (one tailed, alpha = 0.2, 35-1 df) exceeds t ca,c Alternative Species Density Test <br />B for Phase Ill in 2012 is passed (i.e. the null hypothesis of no significant difference is supported). <br />Hence Alternative Test B is passed. <br />Regarding Alternative Test C, the similarity index between the lifeform species density values for the <br />prescribed lifeforms for 2012 BRB PSCM -2 and the Mean Species density (Area- weighted) in the two <br />reference areas is 79.0 percent (Table H -3), exceeding 90 percent of the standard (0.9 x 70% = 63 %). <br />20 <br />