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Average vegetation cover in the reclaimed areas was highest in 1987 (72.1 percent), slightly <br />lower in 1988 (70.9 percent), substantially lower in 1989 (48.1 percent), somewhat higher <br />in 1990 (60.2 percent), and yet higher in 1991 (65.4 percent), though still not as high as in <br />1987, at the beginning of the drought. See 1991 cover tables in Appendix 1 and the 1987, <br />1988, 1989, end 1990 Revegetation Monitoring Reports for the Seneca II Mine. These <br />average figures admittedly are over different numbers of sampled areas and different aged <br />areas, but inasmuch as a range of old to new reclamation of both the Wadge and Wolf Creek <br />areas has been sampled each year, these data may tend to suggest trends: <br />Total Vegetation Cover <br />AREA 1987 1988 1989 1990 1991 <br />ALL 72.1 70.9 48.1 60.2 65.4 <br />Wadge Pasture --- 79.1 70.6 65.4 78.6 <br />Mountain Br. Reference 89.8 85.3 80.1 78.0 85.7 <br />Sagebrush Reference 88.0 76.3 63.2 72.1 78.6 <br />The lower 1989 average vegetation cover reflected a change of 24 percentage points from the <br />vegetation cover measured in 1987. The change in cover from 1987 to 1989 for the <br />• Sagebrush Reference Area was nearly the same as the reclaimed areas at approximately 25 <br />percentage points. In 1990, fhe overall average recovered by about 12 percent, while the <br />Sagebrush Reference Area recovered by 9 percent. In 1991, the Sagebrush Reference Area <br />cover increased by over 6 percent, while the reclaimed area average went up by about 5 <br />percent. <br />On the other hand, the Mountain Brush Reference Area only dropped 9.7 percentage points <br />from 1987 to 1989, but continued to drop another 2 percentage points in 1990. In 1991, the <br />Mountain Brush Reference Area cover increased by nearly 8 percent. Closer examination of <br />the cover data from the Mountain Brush Reference Area show that this net drop of 2 percent in <br />1990 was comprised of a decrease of nearly 11 percent in woody cover along with an increase <br />of nearly 9 percent in herbaceous cover. In 1991, the change was primarily comprised of a <br />nearly 10 percent cover increase in native perennial lorbs that more than compensated fora 2 <br />percent decrease in woody plant cover. <br />It would appear that reclaimed areas respond to environmental changes much more rapidly <br />than the undisturbed areas as represented by the reference areas. In the latter, there is a lag <br />• response that is more pronounced with heavier representation of woody species. In the <br />12 <br />