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involve measurement of total herbaceous vegetative cover. Determination of revegetation <br />success will involve a comparison of vegetative cover data for reclaimed and reference azeas <br />utilizing the "t test" method (Larson, 1980). Reference area data for the grassland (Reference <br />Plot A) and ponderosa/pinon/juniper woodland (Reference Plot B) vegetation types will be <br />combined using a weighted average approach. Consistent with pre-disturbance vegetation <br />boundaries, and disturbed area mapping, the weighting factor will reflect 79.8 percent <br />grassland and 20.2 percent ponderosa/pinion/juniper woodland disturbed. If the absolute <br />value of cover for reclaimed azeas is greater than or equal to the calculated 90 percent <br />confidence level for the weighted-average reference area value, then the means between the <br />azeas shall be determined statistically equivalent and vegetative cover will meet regulatory <br />success standards. <br />Vegetative productivity of reclaimed areas will be evaluated by clipping one quarter square <br />meter circular quadrates along the sample transect. All plant species will be clipped, dried <br />and weighed and determine total vegetative production. If the absolute value of production <br />from the reclaimed area is greater than or equal to the calculated 90 percent confidence level <br />for the weighted-average reference area value, then the corresponding means shall be <br />determined statistically equivalent and vegetative productivity for the reclaimed area will be <br />. judged to be adequate to meet regulatory revegetation success standards. <br />Species diversity will be evaluated for revegetated areas utilizing data from vegetative cover <br />sampling. Species diversity shall be considered adequate when the four (4) dominant <br />species, based on plant cover, comprise no more than 80 percent of the total species <br />composition. The two dominant warm season grass species shall collectively comprise at <br />least 50 percent of total plant cover composition. <br />Because woody plant occurrence in the loadout area is very limited, woody plant sampling <br />data for the loadout area will be compared with the revised woody plant counts for the <br />corresponding reference area as documented in the baseline vegetation data. Revised woody <br />plant counts for the loadout area is 6.3 (2 trees and 1 shrub on 0.48 acre area) stems per acre. <br />If the woody plant density (calculated on a stems per acre basis using woody plant sampling <br />data) for the loadout azea is greater than or equal to the 90 percent confidence interval for <br />corresponding revised woody plant counts, revegetation will be deemed adequate relative to <br />woody plant density. <br />• <br />TR-34 2.05.4-27 Revised 8/02 <br />