Geoscience Reference
In-Depth Information
An epidemic of the mountain pine beetle has been of
great concern during the past 20 years, causing much
speculation about increased fire risk and what land
managers might have done wrong to bring about such
conditions (see fig. 16.9). As noted, for a century or more
fires have been suppressed when possible and the trees
have become more dense. the Forest Service and timber
industry collaborated in harvesting much of the wood
that was produced, though often not at the rate they
would have liked. the industry commonly claimed
the side benefit of improving forest health. others felt
that such harvesting caused habitat degradation over
an excessively large area, or diminished the appeal of
the area to tourists. once again, land managers found
themselves in the middle of debates that often involved
governors and congressmen.
Presently, the furor seems to have diminished. More
people are recognizing that, on one hand, managing
ponderosa pine forests with attempts to suppress all
fires will lead to other problems. Moreover, more people
understand that the insects and diseases prevalent in
the Hills are native—part of the natural biodiversity. to
manage the forest so that insect epidemics did not hap-
pen, or so that large fires did not occur, would create a
manicured forest that never existed before and many
would not like. even more roads would be required.
How to resolve such issues calls for creative collabora-
tion and acceptance of inevitable losses.
current approaches for attempting to solve such
problems include forest thinning and slash removal,
which reduces the fuel load and increases the vigor of
surviving trees. the original structure of some pon-
derosa pine forests is thereby restored, at least to some
degree. Prescribed fires are sometimes used when
weather conditions suggest that the risk of a wildfire
is minimal and there are no mountain homes or busi-
nesses nearby, unusual circumstances in the area. Live-
stock grazing is encouraged for reducing the abundance
of fine fuels, which may have an effect if that biomass is
high after a year or two of above-average precipitation.
in some places the spread of aspen is promoted by cut-
ting the pines, which adds diversity to the landscape
and could slow the movement of pine beetles. Accom-
plishing such management activities over an area large
enough to be effective in a timely manner is difficult.
in fact, the combination of beetles, fire, climate change,
and other factors over a large area will promote the evo-
lution and development of a more sustainable condi-
tion, whether managers take an active role or not.
Invasive Plants, Climate Change, and Sensitive Species
Periodically the managers of federal and state lands are
required to evaluate the ecosystems under their juris-
diction. in the Black Hills and Bear Lodge Mountains,
that includes the Black Hills national Forest, Devils
tower national Monument, Jewel cave national Monu-
Such assessments have been completed recently and, as
expected, all units are concerned about the challenge of
dealing with the consequences of a long history of fire
suppression and mountain pine beetle epidemics. tim-
ber harvesting has been accelerated where that option
is reasonable, and prescribed fires are used when there
has been time to do the required preparation in places
where homes and other structures are either absent or
can be protected.
Federal and state managers also are increasingly vigi-
lant about the threats associated with introduced inva-
sive plants. numerous species are involved, including
buckthorn, burdock, canada thistle, cheatgrass, com-
mon mullein, field bindweed, houndstongue, Kentucky
bluegrass, leafy spurge, spotted and Russian knapweed,
smooth brome, tumble mustard, white horehound, yel-
low toadflax, and yellow sweetclover. curiously, the
managers of Wind cave national Park have observed a
rapid increase in white horehound, an introduced, inva-
sive plant in the mint family that is found primarily
in association with the diggings of black-tailed prairie
dogs. native species are adapted to such habitats as well,
such as scarlet globemallow and fringed sagewort, but
they often are at a competitive disadvantage with the
introduced horehound. Mowing and pulling by hand
are commonly used to keep weed populations in check,
and prescribed burning has been used successfully to
are used carefully and with monitoring to minimize
impacts on other natural resources.
the interaction between white horehound and black-
tailed prairie dogs is especially interesting because,
unlike the native plants, the horehound is not palatable
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