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2.2 FIELD SAMPLING <br />0 2.2.1 Timing <br />Field investigation was undertaken during the period August 6-15, 2009. This time period <br />coincided with anthesis and maximum development of the majority of plant species found in <br />the reclaimed areas at the mine site to be evaluated. <br />Cumulative precipitation for the September-December 2008 period was 2.49 inches, 27.3 <br />percent below the average for those months (3.01 inches). <br />Overall total precipitation for 2009 from January through July was 11.22 inches, reflecting an <br />amount 41.6 percent above average precipitation for that time period. April, June, and July <br />2009 precipitation amounts were significantly above the averages recorded for the mine site, <br />resulting in above average moisture conditions during the 2009 growing season. <br />At the Keenesburg Mine, precipitation relevant to the growing season occurs from September <br />to the following July. Total cumulative precipitation for the period from September 2008- <br />July 2009 was 13.71 inches, the fifth highest value since 1993. Compared to the <br />corresponding averages, this represents a 23.5 percent above the average September-July <br />precipitation amount. <br />2.2.2 Vegetation Cover <br />Vegetation cover was estimated by the use of the point-intercept method. An ocular point <br />frame (ESCO Associates) was used to minimize instrument error and maximize precision <br />and observer accuracy. Cover transects were 25 meters in length, with two sample data <br />points collected at 1.0 meter intervals along the transect on opposite sides of the transect <br />centerline, 1.5m apart. Transect direction was established randomly through the use of <br />computer generated random directions (0-360°). In no event were transects allowed to <br />extend within ten feet of reference or revegetated area boundaries to minimize impacts from <br />"edge effect." <br />For statistical purposes, each cover transect (comprising 50 data points) served as a sample <br />unit. Data points recorded the first vertical "hit" on vegetation (above or below the <br />instrument), soil (bare ground), rock, litter, or cryptogamic crust. Subsequent "hits" on <br />vegetation were also recorded. Cover data were recorded and reported by individual plant <br />species. The first interception was used to calculate total vegetation cover values. Additional <br />interceptions were used to calculate relative cover of individual plant species and lifeforms. <br />The quantitative cover data also provided the basis for calculation of species composition and <br />relative importance. <br />0 <br />Coors Energy Company Keenesburg Mine Page 6 <br />Areas 2, 5, 6, 7, 9,10, 15,16, and 19 Vegetation Study (2009)