PERMFILE53717

• Permit No: C1992081
• IBM Index Class Name: Permit File
• Doc Date: 6/19/2006
• Doc Name: Reference Area Excerpts
• Section_Exhibit Name: Tab 20 Attachment 20-2
• Media Type: D
• Archive: No

sagittata) (3.0 percent cover; 70 percent frequency), and western wheatgrass (Agrooyron
smithii) (1.2 percent mean cover; 70 percent frequency). These four species accounted
for more than 75 percent of the cover (Table I). As a life form group, perennial forbs
accounted for 22 percent of the total cover. The two subspecies of sagebrush accounted
for approximately 60 percent of the total cover. Mean total vegetation cover was ap-
proximately 23 percent and cover by bare soil was f 1.5 percent.
Total production (excluding production by shrubs) was 56.08 g/m2. Western wheat-
grass (19.88 g/m2) and arrowleaf balsamroot (20.63 g/m2) accounted for the majority of
the total biomass (Table 2). Total production was divided almost equally between the
perennial grasses and perennial forbs. Annual and biennial forbs provided only a minor
amount of the total biomass.
Total shrub density along the tie across haul road was 25,500 shrubs per hectare
(10,324 per acre). Of this total, approximately 75 percent were Rothrock big sagebrush
(Table 3). The high schrub density is mostly attributable to the growth form of Rothrock
big sagebrush. As mentioned above, Rothrock big sagebrush tends to be slow-growing
shrub and occurs as numerous small individuals. This characteristic can be seen in the
height Gloss data. Of nearly 19,000 individuals per hectare, almost alt of them are less
than 0.25 meters in height. Mean density for mountain big sagebrush was 6,280 individ-
uals per hectare (2,542 per acre).
There were 55 vascular plant species observed growing in the mixed sagebrush
shrubland type along the realigned portion of the tie across haul road (Table 4). Alt of
these species are typical of western Colorado sagebrush shrublands. None of the species
are threatened or endangered.
Mixed Sagebrush Shrubland Reference-Area
The vegetation in the mixed sagebrush shrubland reference area is very similar to
that occurring along the realigned tie across haul road right-of-wav. The major differ-
ence is that Rothrock big sagebrush is more prevalent and mountain big sagebrush is
somewhat less prevalent than on the realigned tie across haul road site. Totol vegetation
cover, total production, and species composition are comparable on the two areas.
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