Laserfiche WebLink
9 Mean reference area species density (no. of species per 100 square m) - 1.15 s <br />The standard would be based on a weighted average as done with cover and production. In <br />words, the selected standard is the midpoint (in terms of probability distribution) of the <br />lower half of the range of variation of the reference areas. <br />Note that this test addresses total species density, not just native species density (but see <br />Alternative Test C below). Noxious weeds are omitted. The point of addressing total <br />species density, including annual/biennial species and introduced species, is that the total <br />species density is arguably a strong indication of the existence of niche spaces that could <br />eventually be occupied by the native forb and woody plant species typical of the pre- <br />mining plant communities. <br />The final step for this assessment will be a comparison of the mean total species density of <br />the reclaimed area to the reference areas-derived standard number. If the reclaimed area <br />mean exceeds the standard, the Test A is passed. If the reclaimed area mean is less than <br />the standard, a hypothesis test will be undertaken. This would be accomplished using the <br />expression set forth above for a one-sample Mest comparing the reclaimed area species <br />density mean. <br />Alternative Test C: Assessment of the Distribution of Species Density among Life forms <br />• in Comparison to the Reference Areas - This test relates to the distribution of the presence <br />of species among the various life forms in comparison to the reference areas. This <br />standard will use the Motyka similarity index to assess the resemblance of the distribution <br />of species density by life form of the reclamation vegetation to that of the reference areas. <br />Because the average internal resemblance (i.e. between-sample similarity) of applicable <br />reference areas for species density data is often in the range of 70 percent, the proposed <br />standard is 63 percent (0.9 x 70 percent). <br />The Motyka similarity index will be used as follows: <br />IS,,,o = 2c / (a + b) <br />Where: <br />a = total of species density values for life forms of the reclaimed area <br />b = total of species density values for the life forms of the reference area* <br />c = the sum of the smaller of the species density values for life forms of the reclaimed area <br />and the reference areas* <br />* 'Weighted average life form species density using the reference areas <br />Only species density of vascular plants will be included. Life forms to be used will <br />include: <br />Annual/biennial fortis <br />Annual grasses <br />• Perennial forbs/Subshrubs <br />PR-02 2.05.4-7 10/10