Wildlife Management in the National Parks
Methods of habitat management
It is obviously impossible to mention in this brief report all the
possible techniques that might be used by the National Park Service in
manipulating plant and animal populations. We can, however, single out a
few examples. In so doing, it should be kept in mind that the total area
of any one park, or of the parks collectively, that may be managed
intensively is a very modest part indeed. This is so for two reasons.
First, critical areas which may determine animal abundance are often a
small fraction of total range. One deer study on the west slope of the
Sierra Nevada, for example, showed that important winter range, which
could be manipulated to support the deer, constituted less than two per
cent of the year-long herd range. Roadside areas that might be managed
to display a more varied and natural flora and fauna can be rather
narrow strips. Intensive management, in short, need not be extensive to
be effective. Secondly, manipulation of vegetation is often
exorbitantly expensive. Especially will this be true when the objective
is to manage "invisibly" -- that is, to conceal the signs of management.
Controlled burning is the only method that may have extensive
application.
The first step in park management is historical research, to
ascertain as accurately as possible what plants and animals and biotic
associations existed originally in each locality. Much of this has been
done already.
A second step should be ecologic research on plant-animal
relationships leading to formulation of a management hypothesis.
Next should come small scale experimentation to test the hypothesis
in practice. Experimental plots can be situated out of sight of roads
and visitor centers.
Lastly, application of tested management methods can be undertaken
on critical areas.
By this process of study and pre-testing, mistakes can be minimized.
Likewise, public groups vitally interested in park management can be
shown the results of research and testing before general application,
thereby eliminating possible misunderstanding and friction.
Some management methods now in use by the National Park Service seem
to us potentially dangerous. For example, we wish to raise a serious
question about the mass application of insecticides in the control of
forest insects. Such application may (or may not) be justified in
commercial timber stands, but in a national park the ecologic impact can
have unanticipated effects on the biotic community that might defeat the
overall management objective. It would seem wise to curtail this
activity, at least until research and small scale testing have been
conducted.
Of the various methods of manipulating vegetation, the controlled
use of fire is the most "natural" and much the cheapest and easiest to
apply. Unfortunately, however, forest and chaparral areas that have been
completely protected from fire for long periods may require careful
advance treatment before even the first experimental blaze is set. Trees
and mature brush may have to be cut, piled, and burned before a creeping
ground fire can be risked. Once fuel is reduced, periodic burning can be
conducted safely and at low expense. On the other hand, some situations
may call for a hot burn. On Isle Royale, moose range is created by
periodic holocausts that open the forest canopy. Maintenance of the
moose population is surely one goal of management on Isle Royale.
Other situations may call for the use of the bulldozer, the disc
harrow, or the spring-tooth harrow to initiate desirable changes in
plant succession. Buffalo wallows on the American prairie were the
propagation sites of a host of native flowers and forbs that fed the
antelope and the prairie chicken. In the absence of the great herds,
wallows can be simulated.
Artificial reintroduction of rare native plants is often feasible.
Overgrazing in years past led to local extermination of many delicate
perennials such as some of the orchids. Where these are not reappearing
naturally they can be transplanted or cultured in a nursery. A native
plant, however small and inconspicuous, is as much a part of the biota
as a redwood tree or a forage species for elk.
In essence, we are calling for a set of ecologic skills unknown in
this country today. Americans have shown a great capacity for degrading
and fragmenting native biotas. So far we have not exercised much
imagination or ingenuity in rebuilding damaged biotas. It will not be
done by passive protection alone.
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