Geoscience Reference
In-Depth Information
country burned more frequently at times in the past,
notably about 10,000 years ago, when summers were
warmer than today, yet lodgepole pine apparently was
this research suggest that forests of lodgepole probably
will persist in spite of increased burning and insect
activity, though a recent study suggested that the future
climate in some areas may be unsuitable for this pine,
difficult; most likely, the dominant factors bringing
about change will vary from place to place.
But not all Rocky Mountain forests are in roadless
areas. the number of people building homes in moun-
tain forests has increased greatly over the past two
decades because of the appeal of living in such an envi-
ronment. timber harvesting also is an important activ-
ity in much of the West. Large forest fires are of great
concern in these settings. two general approaches can
be used to reduce the threat of fire. the first is local, that
is, reduce the density of trees, shrubs, and other flam-
mable vegetation in the immediate vicinity of a house or
other structure and build the structure itself with non-
the
Firewise
recommendations of the U.S. Forest Ser-
reduction also can be accomplished in forests further
removed from vulnerable structures. the 2000 national
Fire Plan directs federal agencies to conduct thinning
and prescribed fire treatments in this wildland-urban
interface; however, this mandate has proved challeng-
ing to accomplish, in part because most of the interface
the second approach for reducing fire risks is applied
on a broader scale. the objective is to break up continu-
ous fuels and create places where fire spread and inten-
sity can be reduced and where suppression crews can
attack fires effectively when that seems necessary. Forest
fire scientists have identified optimal sizes and position-
ing of fuel reduction sites to achieve the greatest pro-
tection of vulnerable resources for a given investment
driven by high winds coming from more-or-less pre-
dictable directions. therefore, rectangular fuel breaks
of sufficient size placed upwind of a community and
oriented perpendicular to the prevailing winds could be
more effective than similar fuel breaks located down-
wind or oriented parallel to the direction of expected
fire spread. Significantly, the protection afforded by fuel
breaks of this kind are often compromised by glowing
embers, which can be transported by the wind for sev-
eral hundred yards and often ignite new fires. this is a
common cause of fire spread on windy days.
Another landscape-level approach is to prohibit
or discourage home construction in areas of greatest
wildfire risk. this might be best accomplished through
disincentives, such as higher property tax rates and
insurance premiums, or by county restrictions that
reflect the relative fire risk at a given location and the
costs to the community as a whole. Access for fire sup-
pression is often presented as a justification for building
more roads, but most areas in the foothills and adja-
the negative effects of additional roads are discussed in
chapter 18.
How should managers deal with bark beetle out-
breaks? if an outbreak is not already in progress, man-
agers can reduce the likelihood of one occurring locally
by using standard techniques of good forestry, that is,
by thinning and spacing trees for optimal growth and
the maintenance of healthy trees that are capable of de-
stands more resistant to bark beetles in this way is prob-
ably most appropriate on public and private lands where
timber production is an important management goal
or in campgrounds and communities where the death
of many large trees would impair local aesthetics and
create the hazard of falling trees. Such intensive, active
management would be highly controversial in roadless
areas and in the backcountry portions of national parks.
once a beetle outbreak is well under way, stopping
it does not appear to be an option at the present time.
Regardless of management, the outbreak will continue
until bitter cold temperatures at the right time kill
the beetle larvae wintering under the tree bark, or the
high-value trees—such as those in campgrounds, town
parks, or yards—can be protected from beetles even
during an outbreak by repeatedly applying appropriate
insecticides, but, over large areas, that solution has been
prohibitively expensive and problematic to date.
Alternatives are available for handling the trees killed
by the beetles, such as removing them from around
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