|
<br />impact of man on the vegetation. Like many of the areas close to the
<br />foothills and inaccessible to irrigation waters, the Coal Creek area has
<br />been heavily grazed.
<br />
<br />Three major vegetative associations were present: riparian, wet meadow,
<br />and grasslands. The riparian habitat type, which parallels Coal Creek,
<br />is dominated by broad-leafed cottonwood, narrow-leafed cottonwood,
<br />willow, hawthorne, and boxelder (Cancalosi, 1979). The understory is
<br />dominated by grasses, such as redtop, cheatgrass, and bluegrass, and a
<br />variety of sedges, rushes, and forbs.
<br />
<br />Wet meadows, although not extensi ve at the site, a re present in 1 ate
<br />spring and into early summer.
<br />
<br />Grassland dominates the vegetation at the Coal Creek site, and shows
<br />evi dence of deteri orati on due to overgrazi ng. Human acti vi ti es have
<br />degraded the native vegetation from bunchgrass to grassland stands in
<br />trans iti on stages. The domi nant vegetati on i ncl udes cheatgrass,
<br />Kentucky bluegrass, three awn, buffalo grass, cactus, and yucca. To a
<br />lesser degree, wheat grass, needle grass, blue grama, and little blue
<br />stem are present, but do not constitute a majority of the species.
<br />Portions of the project area have been landscaped, and stock ponds and
<br />gravel pits are present. A grove of New Mexico locust has.been planted
<br />in the southern portions of the proposed inundation area.
<br />
<br />Coal Creek Site Terrestrial and AQuatic Life
<br />
<br />Field sampling of the Coal Creek area was carried out during the summer
<br />and fall of 1979. Field studies involved snap trapping of small
<br />mammal s, electroshock i ng for fi sh, and opportuni siti c observati ons for
<br />reptiles, and amphibians, avifauna, and mammals.
<br />
<br />Trapping of small mammals was done during the summer/fall of 1979. The
<br />deer mouse was the most commonly trapped small mammal at Coal Creek, and
<br />was the most abundant speci es captured in each of the habi tat types.
<br />Small mammals observed but not trapped in the riparian transects
<br />include: meadow vole, desert cottontail, muskrat, fox squirrel, and
<br />rock squirrel. In the wet meadow transects, only deer mouse and meadow
<br />vole were captured. Deer mouse was the only species captured in the two
<br />grassl and transects. Several species of small mammal s were observed
<br />during the field studies: desert cottontail, white-tailed jackrabbit,
<br />thirteen-lined ground squirrel, rock squirrel, and northern pocket
<br />gopher.
<br />
<br />The Coal Creek site constitutes part of the winter range for mule deer
<br />in Boulder County but, according to the Fish and Wildlife Service (FWS),
<br />is not of critical importance for this species, (FWS, January 19,
<br />1981). A small herd is known to roam between Coal Creek and the Rocky
<br />Flats area. The area along Community Ditch, both east and west of
<br />Hiqhway No. 93, had a high concentration of deer tracks and was
<br />determined to be an area of high use (Cancalosi, 1979). The Colorado
<br />Divi si on of Wil dl He has noted that thi s secti on of hi ghway is often
<br />crossed by mule deer. White-tailed deer, although not numerous, are
<br />
<br />10
<br />
|