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involve measurement of total herbaceous vegetative cover. Determination of revegetation success will involve a comparison of vegetative cover data for reclaimed and reference areas utilizing the "t test" method (Larson, 1980). Reference area data for the grassland (Reference Plot A) and ponderosa/pinon/juniper woodland (Reference Plot B) vegetation types will be combined using a weighted average approach. Consistent with pre-disturbance vegetation boundaries, and disturbed area mapping, the weighting factor will reflect 79.8 percent grassland and 20.2 percent ponderosa/pinion/juniper woodland disturbed. If the absolute value of cover for reclaimed areas is greater than or equal to the calculated 90 percent confidence level for the weighted-average reference area value, then the means between [he areas shall be determined statistically equivalent and vegetative cover will meet regulatory success standards. Vegetative productivity of reclaimed areas will be evaluated by chpping one-quarter square meter circular quadrates along the sample transect. Al] plant species will be clipped, dried and weighed and determine total vegetative production. If the absolute value of production from the reclaimed area is greater than or equal to the calculated 90 pexcentconEidence level for the weighted-average reference area value, then the corresponding means shall be determined statistically equivalent and vegetative productivity for the reclaimed area will be judged to be adequate to meet regulatory revegetation success standards. Species diversity will be evaluated for revegetated areas utilizing data from vegetative cover sampling. Species diversity shall be considered adequate when the four (4) dominant species, based on plant cover, comprise no more than 80 percent of the total species composition. The two dominant warm- season grass species shall collectively comprise at least 50 percent of total plant cover composition. Because woody plant occurrence in the loadout area is very limited, woody plant sampling data fox the loadout area will be compared with the revised woody plant counts for the corresponding reference area as documented in the baseline vegetation data. The revised woody plant count for the loadout area is 6.3 (2 trees and 1 shrub on 0.48 acre area) stems per acre. If the woody plant density (calculated on a stems per acre basis using woody plant sampling data) for the loadout area is greater than or equal to the 90 percent confidence interval for corresponding revised woody plant counts, revegetation will be deemed adequate relative to woody plant density. MR-48 2.03.4-27 Revised March 2003