Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
Winter Range
Habitat Unit or
LRMP allocation
(forested acres)
Thermal Cover Quality Categories 31 (acreages)
Optimal Acceptable Marginal
3-10
Nonthermal
Sub-Area Totals: acres 32
/percentage of forested
acreage
Pine Mountain- gross
area (5077 ac.)
421 523 1746 10754 944 / 19%
Potholes (5580 ac.) 5 105 1151 8428 110 / 2%
TePee Draw (7734 ac.) 19 334 1318 9249 353 /5 %
Totals:
26550 forested project
acres 25768 acres
WRHUs
21814acres winter range
485 1932 8231 43979
2,417 / 9% forested project
acres
2,169 ac. / 8% WRHUs
1,338 ac./ 6% winter range
The analysis shows that approximately nine (9) percent of the forested acres within the planning area
rates as thermal cover. The general forest land allocation (MA-8) has the highest percentage, 32
percent, but there is no thermal cover requirement for that allocation. It is not utilized by wintering
mule deer because it is also outside of biological winter range.
The acreage within WRHUs is predominately the deer winter range allocation (MA-7). Thermal cover
averages approximately eight (8) percent, but is highly variable between WRHUs, ranging from a low
of two (2) percent in the Tepee Draw WRHU (dominated by black-bark ponderosa pine stands) to a
high of 20 percent in the Lavacicle WRHU (multi-storied lodgepole pine).
When only winter range acres (MA-7) are considered, the percentage of thermal cover declines to
approximately six (6) percent of the forested acres across the project.
Existing Condition Shrub Habitat - Shrubs, primarily bitterbrush, Purshia tridentata (PUTR),
provide critical mule deer winter forage. With approximately 89 percent of the planning area in
designated winter range, the quality, quantity, and distribution of bitterbrush is an important
consideration. They also provide nesting and foraging habitat for shrub-associated species such as the
yellow pine chipmunk and golden-mantle ground squirrel and neotropical migrant birds such as
Brewer’s sparrow, sagebrush sparrow, and green-tailed towhee. Many of these species, particularly the
seed-caching rodents like the the yellow pine chipmunk, serve an important ecological role in the
regeneration of shrub species.
The planning area contains six (6) ponderosa pine plant associations, nine (9) lodgepole pine
associations, and six (6) xeric shrub associations. Three plant associations: ponderosa pine /
bitterbrush-sagebrush (Artemisia spp.) / fescue (22 percent); big sagebrush-bitterbrush / bunchgrass (22
percent); and ponderosa pine / bitterbrush / fescue (19 percent) dominate over 60 percent of the
planning area acreage. In total, approximately 33 percent of the area is in open, xeric shrublands and 67
percent is in forested habitat types.
Table 3-6 summarizes the current conditions of shrub habitats within the planning area.