Using Western Landscapes - Mountains and Plains: The Ecology of Wyoming Landscapes - page 311

Fig. 18.6. Forest fragmentation by clearcutting in the
Medicine Bow Mountains. this mountain range is relatively
flat and accessible, which facilitates harvesting over larger
areas than, for example, in the more rugged Wind River and
Bighorn mountains. this aerial photo was taken in the 1980s.
new trees (mostly lodgepole pine) are now growing in all the
openings. current management prescriptions call for smaller,

irregularly shaped openings, and tree thinning has become
more common than clearcutting. Much of the harvesting in
recent years has been of beetle-killed trees, which provides a
source of wood while reducing hazardous snags along roads
and near campgrounds. Another motivation for harvesting
in some areas is to improve the habitat for specific kinds of
wildlife. See also fig. 18.4. Photo by William K. Smith.

pronghorn return to Jackson Hole in the spring along
the same route. collision mortality and the costs of
vehicle repair have been a serious concern for many
years. to solve this problem, in 2012 the Wyoming
Highway Department completed a system of 25 miles
of 8-foot-high fences that funnel the pronghorn and
deer through six underpasses and across two over-
passes along a 13-mile stretch of road. the $10 million
cost of the project was justified largely by less vehicle
damage. Placing a value on each animal killed is still
difficult.10 . 10 Without accommodations for wildlife, such
as at trapper's Point, widening and dividing highways
to enable faster, safer travel for motorists has the oppo-
site effect on animals.
new roads are often constructed into the foothills,
because homebuilders are attracted to scenic locations
adjacent to national forests and national parks. Un-
fortunately, such places also are important habitat for
some kinds of wildlife, especially during the winter.
People who live there commonly appreciate the abun-
dance of these animals, and sometimes they attempt
to mitigate their own adverse effects, such as with con-

servation easements, bear-proof containers, and habitat
enhancements elsewhere. 11 the effectiveness of such
measures is controversial.

Timber Harvesting and Energy Development

the discussion of habitat fragmentation began about
30 years ago with evaluations of the silvicultural prac-
tice known as clearcutting, whereby all trees are cut
whether they are harvested or not (fig. 18.6; see chap-
ter 12). the rationale for clearcutting was to enhance
the growth and health of new lodgepole pine trees by
providing them with the maximum amount of light,
water, and nutrients, thereby mimicking some effects
of a crown fire. Predictably, logging roads fragmented
the forest still further, with the impact extending well
beyond the roadway. conservation biologists distin-
guish interior from edge forests, and have identified
species, mostly animals, that require one or the other.
timber harvesting and road building can reduce the
amount of interior forest and increase the amount of
edge forest.