Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
Key Issue #1: Effects on Mule Deer Habitat (a) Vegetation Treatments in Deer Habitat; and (b)
Effects of Open Road and Motorized Trails on Habitat Effectiveness.
(a) Vegetation Treatments in Deer Habitat
Approximately 89 percent of the Opine planning area is in the MA-7, (deer habitat winter range), land
allocation of the LRMP. These acres are also identified as biological winter range for deer. The
planning area is currently below LRMP standards and guidelines for both thermal and hiding cover.
Existing forest stands that provide hiding and thermal cover lack structural diversity and contain tree
stocking levels above the historic range of variability. Such stands are increasingly subject to insect
infestation and increased wildfire severity and are not ecologically sustainable. Approximately 1/3 rd of
the planning area is in open, xeric shrublands. Shrubs, particularly bitterbrush provides critical winter
mule deer forage in addition to providing nesting and foraging habitat for shrub-associated wildlife
species. The desired condition for bitterbrush habitats in the planning area is to have a ratio of 1/3 rd in
early seral, 1/3 rd in mid seral, and 1/3 rd in late seral (late and decadent) habitats. Current bitterbrush
habitats are dominated by late seral (late and decadent) habitats totaling 65 percent of the bitterbrush
acreage. Early and mid seral conditions are found on 26 and 10 percent of the bitterbrush acres
respectively.
Measurement Standards:
Percentage of hiding and thermal cover after treatment.
Bitterbrush age/structure ratios
Existing Condition of the Planning Area – Nearly 90 percent of the planning is classified as big game
winter range that is important to mule deer, elk, and antelope. The remainder of the area is summer
range. There is no classified transition range. Mule deer are the predominant big game species across
the planning area and are distributed across the area throughout the year. For the purposes of this
analysis, it is assumed that the requirements of mule deer will meet those of the relatively few elk and
pronghorn antelope that inhabit the planning area.
Approximately 26,549 acres of the approximately 54,623 acres in the planning area are considered
forested. These forested acres contain all or most of the existing and potential hiding and thermal cover
in the planning area.
The Opine planning area is located within the North Paulina Management Unit for mule deer. This is a
subunit of the Paulina herd management unit, as designated by the Oregon Department of Fish and
Wildlife. This unit includes approximately 700,000 acres across both public (including National Forest
and BLM managed lands) and private lands. Approximately 400,000 acres of that area are identified as
summer range. Herd management objectives for this entire management unit
(North Paulina) were established jointly with the Oregon Department of Fish and Wildlife (ODFW).
When the LRMP was adopted in 1990, the management objective for the winter mule deer population
for this management unit was established at 5,500 animals (S&G WL52 LRMP page 4-58). This
objective has been periodically reviewed with the most recent review, December 2004, maintaining this
population objective for this management unit.
Table 3-2 summarizes estimated wintering mule deer populations in the North Paulina management unit
from 1990 to the present. The population index is a measure of how closely the population estimate
comes to meeting the management objective of 5,500 animals for the North Paulina mule deer herd.
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