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• Species diversity will be deemed satisfactory when any two <br />herbaceous species have a relative cover of 5% or greater. This. is <br />approximately half of the number of species that have a relative cover <br />of 5% or greater on the southern exposure reference area. <br />The No. 9 mine portal area was constructed in a wheatfield. As <br />such, the area will be deemed successfully revegetated when the <br />production from the revegetated area is 90% of the standard with 90% <br />statistical. The standard is still being developed at this time. The <br />standard will be the arithmetic mean of five crop production records. <br />In view of the fact that the fields are kept out of production every <br />other year, it will take nine years to generate the historic crop <br />production record. <br />• <br />The fields surrounding the No. 9 portal are kept out of production <br />every other year, but the fields are divided so that data is available <br />from the area around the No. 9 portal for the period of 1979-1983. <br />However, no data is available for 1980. The production records are as <br />follows: <br />Year Production (bushel/acre) <br />1979 12.3 <br />1980 no data available <br />1981 21.6 <br />1982 16.5 <br />1983 18.3 <br />The next area to be discussed will be the No. 5A portal and <br />• surrounding area. The No. 5A portals were developed in the highwall <br />(REV. 12/13/83) <br />IV-98 <br />