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• the youngest (1990) reclamation. Introduced annual and biennial (orbs densities in the <br />reclaimed areas always exceeded those of the reference areas. Introduced perennial fort species <br />were rather uniformly present at about 2.1 to 3.9 species per 100 m2. In the reference areas, <br />introduced perennial forbs were less than one species per 100 m2. Native perennial forb <br />density was greatest in the 1985 and 1988 Wolf Creek areas and 1985 Wadge (7.9, 7.1, and <br />8.1 species per 100 m2, respectively). These figures compared to 18.8 and 11.9 species per <br />100 m2 in the Mountain Brush and Sagebrush reference areas, respectively. Wadge Pasture <br />was observed in 1992 to have 4.7 native perennial forb species per 100 m2, compared to 4.8 <br />species per 100 m2 in 1990, and 4.7 species per 100 m2 in 1991. <br />Total species density of perennial graminoids (introduced and native) in the Mountain Brush and <br />Sagebrush Reference Areas was 6.2 and 7.3 species per 100 m2 in 1992, compared to 4.7 and <br />7.0 species per 100 m2 ,respectively, in 1997, and 3.6 and 6.2 species per 100 m2, <br />respectively, in 1990. The reference area levels of perennial graminoid species density are <br />exceeded in all reclaimed areas. In 1992, the shrub species density in the Mountain Brush and <br />Sagebrush Reference areas was 6.7 and 4.3 species per 100 m2. In the reclaimed areas, shrub <br />species density varied rather narrowly between 0.7 and 1.8 species per 100 m2, except in the <br />• 1990 Wadge and Wolf Creek areas where observed shrub species densities were only 0.3 to 0.4 <br />species per 100 m2. <br />In all reclaimed areas, introduced species, whether annual or perennial, provided the bulk of <br />vegetation cover. In eight of the ten reclaimed areas evaluated in 1990, a single lifeform of <br />introduced plant species (variably introduced perennial forbs, introduced perennial grasses, or <br />introduced annual forbs) provided 45 percent or more of the vegetation cover. In 1991, such <br />dominance was observed only in the older Wadge reclamation (1984 Wadge and Wadge Pasture), <br />but in 1992, it was found in the 1988 Wolf Creek (45.7 percent introduced perennial grasses)' <br />and 1990 Wolf Creek (59.5 percent introduced annual forbs), and came within a few percent in <br />1985 Wolf Creek (44.1 introduced perennial grasses) and Wadge Pasture (42.7 percent <br />introduced perennial forbs and 41.6 percent introduced perennial grasses). <br />The range of native perennial species' contribution to vegetation cover (Table 44) varied from <br />7.8 to 41.2 percent in 1992, compared to 13.4 to 33.7 percent in 1991, and 5.1 to 27.7 <br />• 13 <br />