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2.0 Methods. . 2.8 Sample Adequacy. . nR = reference area sample size sA = affected area sample variance sR = reference area sample variance dA = degrees of freedom, affected area dR = degrees of freedom, reference area The t-value so calculated is compared to a two tailed t-value at 95% confidence (a = 0.05) for (nA + nR)-1 degrees of freedom from a statis- tical table. If the calculated t value is less than or equal to the table t value, the reference and affected areas are deemed "comparable" for the parameter being considered. 2.9 Time of Sampling All quantitative cover, production, and density data were collected in August and early September 1982. 2.10 Species Diversity Species diversity was calculated for each affected area and refer- ence area vegetation type by reviewing the cover data to determine which plants had a relative cover of 3 percent or greater. These species were then grouped by major life-farm. Calculations were based on first-hit data. 2.11 Range Condition and Carrying Capacity Range site descriptions from the Lentral Desertic Basins, Mountains and Plateaus land Resource Area of the Soil Conservation Service (SCS 1971) were reviewed along with soil and vegetation (cover and production) infor- mation from the 1982 field program. Those range sites most applicable to the study area were selected. The percent of original vegetation composition present in each range site was estimated based on the 1982 field cover and production data. The appropriate range condition of each range site was then estimated based on the percent of original vegetation composition present as follows: 0 to 25 percent--"poor"; 25 to 50 percent--"fair";