Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
potential impact on shrubs. However, the target species for control with chemicals are not shrubs and
overspray (e.g. windy conditions) would be avoided. The relatively small area to be treated is minor in
comparison to overall amount and distribution of shrub habitats.
Past and planned timber harvest activities may adversely impact shrubs, but generally this impact does
not exceed 25 percent of an area. Planned and future timber harvest will utilize existing skid trails,
landings and roads which will mitigate these effects. PDCs have been incorporated into all planned
treatments to ensure retention of mature/late shrub age/structure classes within treatment units.
Fuels treatments will have the greatest effect on shrub age/structure classes. Proposed treatments for
both action alternatives are targeting the mature/late structure class, however there are units with
inclusions of the mid stage. There is a PDC is in place to mitigate these effects on the mid class. There
is a limited history in the area on past fuels treatment and their effects have been built into the current
condition shrub classes as noted earlier.
In conclusion, the cumulative effect on shrub habitat is not adverse to objectives for big game species
forage availability, nor for associated shrub dependent wildlife. Over 50 percent of the winter range
area will be retained in the mature/late age/structure class. Large blocks of xeric shrublands will not
have any treatments and will continue to provide high value habitats for a variety of wildlife species.
No shrub dependent species will be at risk to federal listing due to cumulative effects on them.
Part 2 of Key Issue #1
(b) Effects of Open Road and Motorized Trails on Habitat Effectiveness
Habitat effectiveness is affected by open road and motorized trail density. The Opine planning area has
a current average open road density of approximately 2.97 miles per square mile and a combined
average road and motorized trail density of approximately 4.96 miles per square mile. The Fox Butte
Cooperative Travel Management Area program (Green Dot system) reduces open road/motorized trail
densities to approximately 2.92 miles per square mile during the deer hunting season. Target road
densities range from 1.0 to 2.5 miles per square mile within designated deer habitat (M7-22, LRMP
page 4-115) and 2.5 miles or less in other land allocations (WL-54 LRMP page 4-58).
Currently 25,976 acres of the planning area are closed to OHV use except on designated roads and trails
(East Fort Rock OHV area). The remaining 28,647 acres are currently open to unrestricted motorized
use including OHV use. Open roads and unrestricted off-road motorized vehicle use fragment wildlife
habitat and disturb wildlife, especially during winter months when animals must use extra energy and
resources to stay alive.
Measurement Standard:
Miles of system roads closed and decommissioned.
Road and motorized trail density.
Acres closed to unrestricted cross country motorized use.
Habitat effectiveness is primarily influenced by open road and motorized trail density. Big game
species generally avoid the areas adjacent to open roads and trails due to the disturbance from the
vehicles and people. This effect reduces the amount of or use of available habitat in these areas. A
number of variables influence the effects of roads and motorized trails. These include but are not
limited to:
the amount and type of traffic;
the road and/or trail location;
vegetation density and pattern; and
topography.
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