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Species Composition Within the 1995 NGWRA sampling, four lifeforms were represented; graminoids, forbs, succulents, and woody shrubs. The lifefonns included four species of pererutial grasses, two species of annual grass, two annual forbs, one succulent, and six woody shrubs. Of the fifteen species encountered during cover sampling on the new reference azea, native species predominated in number over introduced species, twelve to three. 7'wo grasses and one forb were introduced. The seasonality of the community was divided bE:tween warm and cool reason, with graminoids ew:nly split and the forbs cool season. The shrubs were all deciduous, but tend toward late season anthesis and seed set. Table 't pro~rides a fisting and characterization of the plant species encountered during cover sampling at the NG WRA. Four species accounted for greater than three percent relative cover. These species included Bromus tectorum with 52.63 percent relative cover, Sarcobatus vermi,:ulatus with 20.45 percent relative cover, Hilaria jamesii with 10.12 percent relative cover, and Gutierrezia sarothrae with 5.67 percent relative cover. Sample Adequacy Calculation of the minimum sample size: for a given parameter provides a basis for estimating variability within a vegetation a~mmunity or revegetated area. Total vegetation • cover on the NGWRA was very consistent. Minimum sample size for the total vegetation cover parameter was calculated at three (3) after fifteen samples had been taken. Total herbaceous production was more variable, and a total of fifty samples were collected. The minimum sample size calculated for herbaceous production was 65. Woody plant density was very variable within the NGWRA, partly attributable to the variable quantities of Gutierezzia sarothrae and Chrysothamnus viscidijlorus. A minimum sample size of 121 was calculated based on fifty samples. Tables 2-4 present the sample population parameter values. IV. DISCUSSION AND CONCLUSIONS COMPARISON OF GREASEWOOD 12EFERENCE AREAS The original greasewood reference area was originally selected in 1983 as an area that would be used to compare revegetated areas at the mine for revegetation success. This area was selected to be representative of the greasewood shrubland vegetation community within the mine permit area. Sampling of the original greasewood reference area was undertaken in 1983 by Western Resource Development Company, and the results presented here originate from that sampling which is contained in the Powderhorn Coal • Company CDMG permit document. Recently, both Powderhorn Coal Company and the -6-