2013-10-15_PERMIT FILE - C1982057A (2)

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Where: z = the number of standard deviations (both ways from the mean) encompassing 75% of the normal distribution (= 1.15; see Rohlf and Soka11969, Table P) s = standard deviation (n -1) The standard is the point at which the central 75% of the distribution of overall species density in the Reference Areas begins. Mathematically this would be: Mean Reference Areas species density (no. of species per 100 sq.m.) - 1.15 s In words, we are selecting as the standard the midpoint (in terms of probability distribution) of the lower half of the range of variation of the Reference Areas. Note that this test addresses total species density, not just native species density (see Alternative Test D below). (Noxious weeds will be omitted in conformance with other existing requirements). The point of addressing total species density, including annual /biennial species and introduced species, is that the total species density is arguably a strong indication of the existence of niche spaces that could eventually be occupied by the native forb and woody plant species that exist in the Reference Areas. The "best" (in the agricultural sense) stands of grass might not qualify because they would have crowded out the "weeds" (which, in the agricultural sense, means most of the species that we are interested in here). At the other end of the spectrum, protection from accepting an actual "weed patch" is assured by requirements limiting the participation of noxious weeds in cover and production standards. The final step for this assessment would be a one - sample t -test comparing the reclaimed area species density mean against the Reference Areas standard number (described above). For Example: If Reference Areas species density in the test year has a mean total species density of 25.2 species per 100 sq.m. and a standard deviation of 5.3, the standard would be: - (1.15)x5.3 =19.1 MR -66 52 Revised 10/09