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have been carried over to reclamation of lands disturbed by road construction, mining, <br />fire and other large disturbances. <br />Typically, early seed mixtures for reclaimed rangeland had relatively few plant species. <br />Generally, plant available soil moisture and precipitation were adequate to allow seed <br />to be drilled in rows at fairly high seed density. These planting methods most <br />frequently resulted in mono - cultural stands of aggressive cool- season grass species. <br />These cool- season grass stands were effective in reducing weed infestations, but their <br />biologic diversity was low and the stands were more susceptible to disease (R. <br />McGuffin, 1987). <br />One of the first modifications to this high density seed rate /low species diversity seed <br />mix mentality finally came in 1968 with the publication of "Restoring Big -Game Range <br />in Utah" by Plummer, Christensen and Monsen. They compiled more than 10 years of <br />research initiated by the Utah Fish and Game and the USFS in 1955 to determine the <br />methods to stabilize watersheds and improve range productivity. Their research <br />determined that seeding rates of 8 to 10 pounds of seed per acre was adequate to <br />establish a good stand of native grass, forb and shrub species if the seeds were of <br />acceptable purity and viability (Plummer et al., 1968). This seeding rate is estimated to <br />be approximately 18 seeds per square foot. These researchers initiated the concept of <br />Pure Live Seed ( "PLS "). PLS is determined by multiplying the purity by germination <br />and dividing by 100. For example, if purity of a given seed sample is 95 percent and <br />germination is 80 percent, the PLS would be 76 %. Seeding rates on sites with less than <br />12 inches of precipitation were applied at rates approximately 25 percent lower than <br />sites with more than 12 inches of precipitation or approximately 13.5 seeds per square <br />foot (Plummer et al., 1968). <br />Since the late 1970's, coal mine reclamation has been mandated by various state and <br />federal laws (SMCRA, 1977). These laws required the establishment of a diverse cover <br />Appendix G 13 07/01/02 <br />