2006-06-02_PERMIT FILE - C1980007 (5)

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GVest Elk Mine • and Kentucky bluegrass. These grasses accounted for about 87 percent of the total vegetation cover. Common forb species included morning-glory, dandelion and Oregon fleabane (Erigeron speciosus). Total production for the affected dry meadow was 278.86 grams per squaze meter. Grasses accounted for 94 percent of the total biomass (Exhibit 32). Western wheatgrass was the most productive species with 187.23 grams per square meter. Perennial and annual forbs provided about 6 percent of the total biomass. hi the reference azea, the total production was 363.91 grams per square meter (Exhibit 33). Grasses were most important and accounted for 351.33 grams per square meter. Western wheatgrass and smooth brome were the most productive species with 249.30 and 96.02 grams per squaze meter, respectively. Perennial forbs accounted for 3 percent of the total. Annual forbs were of very minor importance, accounting for less than 0.1 percent of the total biomass. The affected area had a greater species diversity with 6.3 species per square meter while the reference plot has 4.4 species per squaze meter. The difference was related to the higher number of forb species encountered in the affected azea. Most of the forb species were weeds and aze characteristic of disturbed areas. As mentioned eazlier, the large meadow in the affected area appeazed to have been bulldozed. It should, therefore, be recognized that many meadow communities occur as a function of human manipulation. As such, they may not be in a state of equilibrium with the surrounding environment. The level of management on both the affected and reference areas of the dry meadow vegetation type has been similaz over the years. Both areas were close to homesteader's cabins and were probably cleared to provide acreage for crops and gardens. In addition, Mr. Hazold Ross has grazed livestock on both azeas for the past 25 yeazs. Thus, both azeas have been subject to human manipulation in Terms of brush clearing and grazing by livestock for an extended period. These considerations were evaluated during the reference area selection process, and for these reasons, MCC believes that the dry meadow vegetation type reference azea is as comparable to the affected azea as can be reasonably expected. In order to evaluate the similarity between the dry meadow control and affected azeas, t-tests were conducted on the cover and productivity data. In both tests, the difference was significant. The reference azea had significantly higher cover and production. As a second means of comparison a similarity index between the affected azea and reference area was calculated on the basis of relative cover (percent of total cover). The percent similarity was obtained by surruning the amount of relative cover shared by each of the species in the affected and reference areas. On this basis, the two areas were 69,2 percent similar. Even though the reference azea has significantly greater cover and production, MCC still considers it a suitable site for a reference area. It is the only compazable site located neaz the affected area and outside the area of mining activity. Also, because the cover and production reclamation standazds based on this reference area would ensure that the affected azeas aze more than adequately reclaimed. The dry meadow reference azea is no longer proposed for use in determining revegetation success criteria. A historic record approach was initiated in 1996 (PR07), to determine site- 2.04-150 Revised November 2004 PRI G