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e ESPEY, FIUSTON &ASSOCIATES, INC. i The study site is in the mountain and plateau montane life zone as described by Harrington (1964), the brushland community of Shelford (1963) and the mountain mahogany-oak/scrub community as mapped by Suchler (1975). 3.2 PLANT COMMUNTfIES OF THE PROPOSED PERMTT AREA The mountainous terrain of the study site is chazacterized by moisture and temperature gradients as influenced by elevation, slope, aspect and drainage patterns. These environmental variables have interacted with the regional flora through time to produce several distinct community types common to broad azeas of western Colorado. A meadow community dominated by sedges (Cazex spp.) and rushes (Juncos spp.) occurs in the deep, moist soil habitats of the drainages. Surface water is generally available throughout the growing season in this community. Those • drainage habitats that have surface water in the spring, but gradually dry with the approach of summer (a drier phase of the community) are dominated by native bluegrass (Pon spp.). This dry meadow phase often occurs on the perimeter of wet meadows and in the less moist drainage bottoms. The deep but well-drained heavy soils of the flatter portions of drainage basics support a mixture of low-growing shrubs dominated by big sagebrush with a vaziable understory of perennial grasses and forbs. The height and cover of shrubs increase with increased moisture of the habitat. Habitats immediately along streams support the most vigorous sagebrush stands. The big sagebrush community is gradually replaced by a dense deciduous shrub community as topography increases in percent slope and with elevation. Soils of the mountain shrub habitat are deep and well-drained and retain moisture through spring and eazly summer. Variability in soil depth and soil moisture conditions result in vaziability in shrub dominance. Oak and serviceberry aze the major shrub species • K-11