APPCOR11574

• Permit No: C1981071
• IBM Index Class Name: Application Correspondence
• Doc Name: DESCRIPTION OF EXISTING ENVIRONMENT
• Media Type: D
• Archive: No

~ ~ III IIIIIIIIIIIII III
816.111 - .117 REVEGETATION
A. Description of Existing Environment
1. The climatic conditions for the area are representative of the region.
Based on data obtained at Hayden, Colorado, annual precipitation averages
14.6 inchesl with most of it in the form of snow during the fall and
winter. The average rainfall for the period of April through September
(normal growing season) was 6.4 inches. The average annual maximum
temperature of 85 degrees F. occurred in July and the average annual
minimum of 3.6 degrees F. occurred in January. During November through
March the average monthly temperatures were below freezing.
Meteorological monitoring of the proposed permit areas since 1977
substantiates the more general regional climatic data (Section 816.95).
Descriptions of the existing environment were derived from baseline
studies conducted by Energy Fuels during 1979. Estimates for ranges in
productivity and carrying capacity were obtained from those projected by
USDS SCS for the appropriate range sites. Soils information is from p.
779-126 M.R.P.
(1) Aspen (Populus tremuloides)
This cover type comprised 563 acres (31"e) of the area to be mined.
It was located on the upper elevation (7,000 to 8,200 feet) on all
aspects of gentle [o moderately sloping topography (3-65%) in the
Eckman Park area (southern portion of the permit area). The 70D and
70F soils associated with this type (inconsistent, see 816.97 section
F. stipulation No. 1) were azonal, about 22 inches deep, sandy loam
in texture, highly permeable and had low erosion hazard.
Aspen dominated the type with a generally dense crown cover. Stem
density averaged about 0.22 stems per m2 (890 stems per acre).
Understory shrub species were chokecherry (Prunus virginiana),
serviceberry (Amelanchier alnifolia), snowberry (Symphoricarpos
oreophilus), with some rose (Rosa woodsii), currant (Ribes spp.) and
Oregon grape (Mahonia repens). These accounted for about 21% of the
species composition. The average ground cover composition was 58Y.
grasses, and 21% forbs. The most common grasses were bluegrass (Poa,
~), mountain brome (Bromus marginatus), and blue wildrye (Elymus
¢laucas). The most common forbs were yarrow (Achilles lanulosa),
American vetch (Vicia americans), pennycress, (Thlaspii fendleri),
giant hyssop (AQastache spp.), and bedstraw (Galium bifolium). Based
on Bonham's (1974) modification of the index to diversity developed
by McIntosh (1967), the Aspen site received an index value of 0.913.
This value reflected the 7 grass, 20 forbs and 7 shrub species (34
total) that comprised Che type. The average litter cover was 41% and
the canopy cover for grasses, forbs, and shrubs was 15, 22 and 19
percent respectively, for a total cover of 97 percent.