Environmental Assessment

AFFECTED ENVIRONMENT & ENVIRONMENTAL CONSEQUENCES CHAPTER 3
complete loss of thermal cover in affected areas. Alternative 1 has the greatest risk of a bark beetle
attack and/or potential for a high intensity wildfire that would likely result in the loss of all or most the
existing cover.
Impacts to soils and vegetation from a wildfire given the relatively low quality of these sites could take
multiple decades if not a century or longer. This is evident by large areas within the 1959 Aspen Flats
fire, which at present remain devoid of thermal and hiding cover, 47 years later. A wildfire ignited
today is more likely to be of a higher intensity due to greater fuel loadings.
The more recent Skeleton, Paulina, and Evans West fires have also eliminated large areas of both tree
and shrub cover, including important browse species such as bitterbrush. Local experience suggests
that recovery of bitterbrush will also likely take several decades. Without planting, recovery of thermal
cover to current levels would likely take multiple decades depending upon the severity and intensity of
the fire.
Bark beetle attack and wildfire events would be expected to have less impact in lodgepole pine stands.
Similar to such events in ponderosa pine, existing thermal cover would be lost. The generally rapid
regeneration characteristic of lodgepole pine and its adaptability to stand replacement fire events
suggests that recovery of thermal cover in these stands would likely occur at a much faster rate than in
ponderosa pine stands experiencing a similar event. Recovery could occur within 4 to 6 decades.
Alternative 2 (Thermal Cover): would result in the removal of 1,727 acres of optimal and acceptable
thermal cover. Almost all, 98 percent, of the reduction is associated with vegetation treatments; the
remaining 2 percent with fuel reduction treatments. Thermal cover across forested habitats at project
scale would decline to 690 acres or 2.6 percent of those acres. Within WRHUs, thermal cover would
encompass 665 acres or 2.6 percent of the WRHU acreage. The percentage drop is greatest in the
winter range only, declining to 614 acres or 2.8 percent of the acreage.
Alternative 3 (Thermal Cover): would result in the removal of approximately the same number of
acres as Alternative 2, 1,749 versus 1,727 acres, but results in fewer acres and lower percentages of
acceptable and optimal thermal cover. Cover levels would decline to 720 acres or 2.7 percent of the
forested habitat acres at project scale; 656 acres or 2.5 percent of the WHRU acres; and 615 acres or 2.8
percent of the winter range only acres. Similar to Alternative 2, almost all, 99 percent, is associated
with vegetation treatments; the remaining one (1) percent with fuel reduction treatments.
Alternatives 2 and 3 (Thermal Cover): Alternative 2 would result in a decline in thermal cover,
including optimal and acceptable, from nine (9) percent of the acres across the entire planning area to
2.6 percent. Under Alternative 3, existing optimal thermal cover would be retained by including it in
the retention portion of the unit. No optimal thermal cover would be lost under this alternative and
would remain at less than 2 percent across the planning area. Within WRHUs, the decline under
Alternative 2 would be from the current eight (8) percent average to 2.6 percent. There would be no
change under Alternative 3 which would remain at 1.9 percent. Post-thinning canopy closures would
drop to approximately 20 percent in treated stands under both alternatives. Areas targeted for
vegetative treatments contain the higher quality cover, particularly thermal cover. But these acres also
are at the highest risk for bark beetle infestation. Although such treatments result in an immediate
short-term reduction in cover, over the longer term, cover levels, both thermal and hiding, would be
expected to slowly increase.
Pretreatment of understory trees, trees four (4) inches dbh and less, during post-harvest fuel reduction
treatments would result in very little loss of thermal cover habitat. Cover in these tree sizes is primarily
associated with foliage (i.e. hiding cover). Evidence from treatments in other similar stands suggests
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