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was and continues to be, Bromus inermis for all years sampled. As noted above, <br />Agropyron smithii has shown a significant increase in relative cover from the initial <br />sampling of the HRSA in 1996 to the most recent sampling in 2010. Three additional <br />plant species (Bromus inermis, Poa pratensis, and Convolvulus arvensis) were found to <br />be dominant or major components of each community during all years sampled. Two <br />species, Bromus inermis and Convolvulus arvensis were present in both the dry meadow <br />reference area and the historic record vegetation community in approximately the same <br />relative percentages over the years sampled. Additionally, one perennial composite forb <br />appears as a persistent component of each community. In the dry meadow community <br />that species was Erigeron speciosus (purple erigeron), while in the dry meadow reference <br />area Taraxacum officinale (dandelion) and Erigeron speciosus were present in 1982, and <br />Taraxacum officinale prevailed in 1995. In the historic record vegetation community, <br />Erigeron flagellaris has become the prevailing perennial forb at the HRSA, and has <br />become one of the dominant species in terms of relative cover at the HRSA. <br />Herbaceous production in the communities sampled showed a general correlation with <br />"pre-growing season" precipitation. As discussed above, the total herbaceous production <br />increase in the historic record vegetation community correlated nearly exactly in increase <br />from 1996 to 1997 and decreased less (proportionally) than precipitation from 1997 to <br />1998. The correlation between "pre-growing season" precipitation and all sampling years <br />at the HRSA was not as high when the 2010 data was incorporated, likely due to the <br />community development discussed above (Table 7). <br />A similar correlation between "pre-growing season" precipitation and herbaceous <br />production was not present in the dry meadow and dry meadow reference area between <br />1982 and 1995. With an increase in precipitation, a decrease in production occurred. <br />This does not represent the generally observed relationship, and it is hypothesized that <br />this anomalous observation is related to sampling technique differences. <br />6.0 SUMMARY AND RECOMMENDATIONS <br />The historic record study area was created in 1996 to provide a location for sampling a <br />vegetation community representative of that which could be expected to be re-established <br />during reclamation at the West Elk Mine. Vegetation sampling was initiated in the <br />historic record vegetation community in 1996, and continued in 1997 and 1998. <br />Vegetation sampling was re-initiated in 2010. <br />Quantitative vegetation sampling of four vegetation parameters was undertaken at the <br />historic record vegetation community in 2010. Based on the prevailing precipitation <br />regime for the 2009-2010 growing season, it was established that the 2010 historic record <br />vegetation community parameter values were representative of a "dry" precipitation year <br />("pre-growing season" precipitation value less than 8.45 inches) at the vegetation <br />community. Total vegetation cover, total herbaceous production, and species numbers <br />values generally reflected the level of "pre-growing season" precipitation, however it was <br />noted that the hiatus in sampling at the HRSA (12 years) revealed development of the <br />graminoid community and species that appear more robust, yielding greater total <br />Mountain Coal Company, LLC Page 11 <br />Historic Record Study Area Vegetation Sampling Report: 2010