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• <br />• <br />Cover. Total plant cover on this site averaged 26.60 percent and litter cover averaged 33.47 <br />percent. <br />Shrubs and subshrubs were the dominant plant life form encountered on this site, contributing <br />12.47 percent of the total plant cover and 46.87 percent of the total relative cover found on this <br />area Annuals and biennials were the second most dominant plant life form, contributing 8.40 <br />percent of the total plant cover and 31.58 percent of the total relative cover found on this area. <br />Native perennial grasses contributed 2.80 percent of the total plant cover and 10.53 percent of <br />the total relative cover found on this area. Perennial forbs contributed 2.73 percent of the total <br />plant cover and 9.52 percent of the total relative cover found on this area. Basin Big Sagebrush <br />was the dominant plant species encountered, contributing 31.58 of the total relative plant cover <br />found on this site. The other dominant plants encountered were: Storksbill, Cheatgrass Brome, <br />Broom Snakeweed and Rubber Rabbitbrush which contributed 13.28, 11.53, 5.26 and 5.26 <br />percent, respectively, of the total relative cover on this area. The locations of the 15 cover <br />sampled in the Sagebrush predisturbance area are shown on Map 2.04.10 -1, Permit Area <br />Vegetation Map. The sample adequacy calculations in Appendix Table 2.04.10 -2, New Horizon <br />North Mine Area - Sample Adequacy Calculations, document that the number of samples <br />required to describe this site at the 90 percent confidence interval was 10.0 transects. <br />Production. The results obtained from the sampling of 50 production transects on this area are <br />summarized in Appendix Table 2.04.10 -7, Sagebrush - Production. This table shows that the <br />average total herbaceous forage production on this site equaled 3.46 g/1 /4 m or 123.3 pounds of <br />air dry -dry forage per acre. Perennial grasses contributed 1.78 g /1/4 m or 51.44 percent of the <br />herbaceous forage produced on this area. Perennial forbs, contributed 1.68 g/1 /4 m or 48.56 <br />percent of the herbaceous forage production on this area. <br />Evidence of the relatively poor ecological condition of the Big Sagebrush vegetation type is <br />found in the NRCS Soils Survey by comparing our monitoring data with that reported to occur <br />on the Semi Desert Loam and Pinyon - Juniper ecological sites, which correspond to the soils <br />types found in these Sagebrush areas. In the Soils Survey, herbaceous forage production for <br />these two ecological sites is reported to average 600 and 300 pounds of forage per acre, <br />respectively. This comparison suggests that the Big Sagebrush vegetation type is producing only <br />approximately between 20.6 and 41.1 percent of its ecological potential. This comparison <br />documents the relatively poor ecological condition of this vegetation type. <br />The locations of the 50 production transects sampled on the Big Sagebrush vegetation type are <br />shown on Map 2.04.10 -1, Permit Area Vegetation Map. The sample adequacy calculations in <br />Appendix Table 2.04.10 -2, New Horizon North Mine Area - Sample Adequacy Calculations, <br />document that the number of samples required to describe this site at the 90 percent confidence <br />interval was 187.7 transects. <br />• Section 2.04.10 Page 12 April 2011 <br />