2015-04-08_REVISION - C2009087 - Laserfiche WebLink

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Peabody Sage Creek Mine July 2014 SL -3 Phase III Bond Release Request Alternative Test Q: Species Density Distfibution Assessment Among Lifeforms This test relates to the distribution of species presence among the various lifeforms in comparison to the reference areas. This standard uses the Motyka similarity index to assess the resemblance of reclamation vegetation species density distribution by lifeform to that of the reference areas. Because the average internal resemblance (i.e. between- sample similarity) of applicable reference areas for species density data is often in the range of 70 %, the standard is 63% (0.9 x 70 %). (The assessment of internal similarity was performed on data from the reference areas.) The Motyka similarity index is used as follows: ISmo = 2c / (a + b) Where: c = the smaller of the paired species density values (for each lifeform) of the reclaimed and reference areas* a = total of species density values for lifeforms of the reclaimed areas b = total of species density values for the lifeforms of the reference area* * Weighted average lifeform species density using the PSCM Reference Areas (weighted based on 83% original extent of Mountain Brush and 17% original extent of Sagebrush). Only species density values by vascular plants are included. Lifeforms used include: Annual /biennial forbs Perennial forbs Annual grasses Perennial cool season grasses If the index of similarity between the species density within the specified lifeforms of the reclaimed and reference areas exceeds 63 %, then Test C is passed. Alternative Test D): Native Species Presence Assessment The third alternative assessment of the reclaimed land species diversity makes direct reference to the presence of native western North American plant species in reclaimed areas as follows: Total cumulative # of native species* >_ avg. reference area native species density ( #species /100 sq.m.) 19