|
West Elk Mine
<br />The next most abundant species were servicebetry and chokecherry with 10,460 (4,235/acre),and
<br />9,280 (3,757/acre) individuals per hectare, respectively. Wood's rose was the least abundant species
<br />with 740 individuals per hectare-(300/acre). Gambel oak, western snowberry, and serviceberry had
<br />the highest mean cover values with 64.9, 20.6, and 13.8 percent respectively (Exhibit 33). Mean
<br />total shrub density in the oakbrush reference area was 53,320 individuals per hectare. The most
<br />abundant species was Gambel oak with 17,800 individuals per hectare (7,206lacre). Of this total,
<br />approximately 49 percent were in the height class 0.25m-0.75m, 18 percent were in the second
<br />height class, and 26 percent were in the fifrh height class. Western . snowbeny, serviceberry,
<br />chokecherry were the next most abundant species with 12,080 (4,891/acre), 11,240 (4,551/acre),
<br />and 9,660 (3,911/acre) individuals per hectaze, respectively (Exhibit 33). Most of the individuals
<br />(79 percent) of western snowberry were in the first height class whereas the other two species were
<br />variably distributed throughout the five height classes. Three other species, including Wood's rose
<br />(Rosa woodsii), hawthorn (Crataegus douglasi:), and red cedar (Juniperus virginiana) had density
<br />values of 2,150 (866/acre), 360 (146/acre), and 40 (16/acre), respectively. Gambel oak,
<br />serviceberry, and western snowbetry had the highest mean cover values with 58.7, 20.4, and 18.0
<br />percent, respectively.
<br />Differences between the reference area and the affected area were also evaluated using t-tests. The
<br />difference in production between the two azeas was not significant at the 95 percent confidence
<br />level, however, the differences in shrub density and total vegetation cover were significant.
<br />The oakbrush reference area is no longer proposed for determining revegetation success criteria. A
<br />historic record approach was initiated in 1996, to determine site-specific revegetation success
<br />criteria for the West Elk Mine.
<br />1995 Refuse Pile Exaansion (RPE) Area Ve¢etation Community Samalin~
<br />In 1995, MCC planned a second coal refuse pile in a location east of Sylvester Gulch on the toe
<br />and sideslopes between Sylvester Gulch and an unnamed gulch to the east. The RPE azea was
<br />not anticipated during the initial permitting of the mine; therefore, sampling of the undisturbed
<br />vegetation communities present within the area proposed for disturbance was required by the
<br />CDMG.
<br />Vegetation communities were identified through aerial photography and field reconnaissance.
<br />Oakbrush dominates the north-northeast facing slopes and toeslopes. A minor wetland
<br />community dominated by cottonwoods and willows is present adjacent to Highway 133.
<br />Narrowleaf cottonwoods dominate a minor cottonwood seep vegetation association adjacent to a
<br />bedrock seep on the slope of the RPE azea. Along the sandstone outcrops on the eastern portion
<br />of the RPE area slope, a mixed conifer community is present.
<br />Oakbrush Vegetation Community
<br />The general composition of the oakb:,tsh community was that of a multiple storied low forest.
<br />The stories were composed of a tree or tall shrub component (>3 meters in height), a medium
<br />height (I-2 meter) shrub component, and a low herbaceous graminoid and forb component. The
<br />upper canopy was dominated by Quercus gambelii (Gambel oak) with occasional Juniperus
<br />2.04-150 RevisrAApn1200~ PR10
<br />
|