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x rev = Average herbaceous production, reclaimed area <br />MDa = Mesic drainage, premine type percentage affected by mining <br />IPSa = Improved pasture - subirrigated, premine type percentage affected by mining <br />xMD = Average reference area herbaceous production, mesic drainage <br />•IPS = Average reference area herbaceous production, improved pasture <br />- subirrigated <br />The production success standard for the reclaimed areas of the haul road corridor will be based on the <br />herbaceous production of the haul road corridor reference area. The vegetation production in the <br />reclaimed haul road corridor will be considered successful if it is not less than 90 percent of the <br />production standard with 90 percent confidence. The formula describing this is: <br />where: <br />xrev > •90 NIRC.) <br />xfev = average herbaceous production, reclaimed area <br />xI(RC = average herbaceous production for the haul road corridor reference area <br />IsSpecies Diversity <br />Since the time that the diversity standards for the original Yoast Mine permit were proposed, a more <br />comprehensive consideration of the nature of plant diversity on reclaimed areas as compared to un- <br />mined areas (reference areas) has been completed. The result is the set of proposed standards below: <br />Background. The bulk of reclamation sites have used a seeding strategy that emphasized grasses to <br />assure adequate erosion control, and even when those grasses are native species, the competitive <br />advantage of this Heform over forbs and woody plants is evident at many mine locations. In the short <br />and medium term, it seems unavoidable that species diversity will be less than that of most un -mined <br />comparison sites (or baseline conditions). <br />This is not because of faulty seed mixes, or poor seeding technique, or any particular short - coming of <br />planting a regraded /topsoiled site. One of the lessons of the large -scale experiment represented by <br />mine revegetation since the late 1970's is that given decent topsoil and reasonably favorable moisture <br />• conditions, the presence of species other than grasses is not subject to a "plant them and they will <br />come" direct approach. Rather, the circumstances that have driven (or have resulted in the pre- <br />RN -03 40 Revised 10/10 <br />