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<br />As in the effected area, pinyon pine and Rocky Mountain juniper <br />ere the dominant plants with 43.7 end 7.0 percent cover, respectively, <br />Mountain mahogany end Gambol oak ere common understory shrubs. <br />Mutton-grass, a short to mid cool season bunchgrass, is the most abun- <br />dant graminoid with 2.7 percent cover. Bluebunch wheatgrass is also rel9- <br />tively common with 1.0 percent cover. <br />The average production for the Pinyon-Juniper Woodland reference <br />area is 13.8 g/m2 or 123 pounds per acre. This is comparable but slightly <br />lower Than the effected area production of 16.6 q/m2. Mutton grass is the <br />dominant producer in the reference area 14.2 g!m 1. Bluebunch wheatgrass, <br />while common, is not dominant in this understory es in the affected Brea. <br />This may be attributed to the small size of the reference area which <br />contains little variation in physical environmental factors such as slope end <br />aspect. Because of the lack of habitat variability fewer plants occur in <br />the production data for the reference area. See Table 3.4.1-2. <br />Total tree density in the reference area is slightly higher <br />306 per acre) than the affected area 1290 per acre). Pinyon pine is the <br />most abundant tree 171 percent abundance) followed by Rocky Mountain juniper <br />129 percent). Pinyon pine has an average height and DBH of 6 meters and 20 <br />centimeters, respectively, Rocky Mountain juniper is slightly smaller with <br />• an overage height of 5 meters end an average DBH of 16 centimeters. See <br />Table 3.4.1-3. <br />The mean shrub density of the reference area is 331 per acre. <br />This is lower than the density for the affected area, 613 per acre. The <br />reference area lacks the topographic and habitat diversity of the affectetl <br />area and correspondingly has a lower abundance and density of shrub species. <br />Similar species are present in both affected and reference areas but <br />dominance varies. See Table 3.4.1-4. <br />3.5 Species Diversity <br />Diversity (richness of species) and equitability (evenness of cover <br />distribution) indices are derived from the cover data for the Pinyon-Juniper <br />Woodland (affected end reference) and the Rubber Rabbitbrush Snrubland. <br />Diversity i5 higher in the Pinyon-Juniper Woodland. This is expectetl as the <br />Rubber Rabbitbrush Shrubland area was at one time a monoculture of crested <br />wheatgrass. Equitability is low and identical in the two vegetation types <br />due to the dominance of two species in each vegetation type. See Table 3.5-1. <br />Diversity antl equitability are slightly lower in the Pinyon-Juniper <br />Woodland reference area than in the effected area. This result is expected <br />as the reference area does not include the habitat variability of the larger <br />effected area. <br />• <br />-20- <br />