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Challenges of Snag Management 1
Gregory A. Goodwfn2
and
Russell P. Bal da3
Abstract. -- Snags provide needed resources for 85
species of North American birds, numerous plants, invertebrates, reptiles, amphibians and mammals. Snag habitat
research and management needs can be broken down into six
general categories: 1) establishing realistic economic
values for nongame wildlife and habitat improvements; 2)
finding answers to questions raised by the National Forest
Management Act; 3) understanding the role of snag-dependent
birds and mammals in forest ecosystems; 4) developing methods
to create snag habitat and improve snag habitat for selected
species; 5) learning to integrate snag management and
fuelwood management; 6) pursuing intensive public information and law enforcement programs. These areas of study are
needed to provide managers with information for making management decisions.
INTRODUCTION
selection has adaptive value for each species
in terms of survival and reproduction, yet in
many cases we may not be able to detenmine
these requirements because management practices
have already removed the optimum, and species
may be existing under suboptimal conditions.
Snags provide needed resources for 85
species of North American birds, (Scott et al.
1977) numerous plants, invertebrates, reptiles,
amphibians, and mammals. It is generally assumed and supported by empirical findings
that a direct relationship exists between the
number.of snags present and population levels
of snag-dependent wildlife species occupying
an area. Ma~ species of snag-dependent birds
have declined because of habitat reduction.
The ivory-billed and redcockaded woodpeckers
are currently on the endangered list. The
wood duck now depends heavily on artificial
nest boxes for its continued survival. European
forests, which are intensively managed, support
no snags, and consequently artificial means must
be used to sustain rna~ species of wildlife.
In rna~ forested areas, past management
activities have reduced and even eliminated
the potential of forests to produce and retain snags. Dead and dying trees which would
have become snags were routinely removed during
sanitation cuts. Existing snags were removed
for safety reasons and for many years were
methodically cut down as fire hazards. Shorter
rotation intervals have eliminated older stands
resulting in a reduced potential to produce
1arge diameter snags.
Only during the past 10 years have land
managers begun to recognize snag management
problems and the inherent values of snags. Research conducted on snag ~namics and habitat
requirements of snag-dependent wildlife has contributed to the implementation of snag management policies by Federal land management agencies.
However, this is only the beginning of management
of the snag resource. Six general categories of
research and management needs are necessary to provide resource managers with the kind of infonmation
necessary for making wise snag management decisions.
Each forest community supports a distinct
group of snag-dependent wildlife species which
have evolved through time to fill a particular
role in the ecosystem. Each wildlife species
has distinct requirements for diameter, age,
height, and species of snag it uses. This
lpaper presented at the Snag Habitat
Management Symposium, Flagstaff, Arizona.
June 7-9, 1983.
2wildlife Biologist, USDA Forest
Service, Coconino National Forest, 2323 East
Greenlaw Lane, Flagstaff, Arizona 86001.
3Professor of Biology, Department of
Biological Sciences, Northern Arizona University,
Flagstaff, Arizona 86011.
ECON<J.1IC VALUES
As managers and researchers, we are still
concerned about establishing, and more importantly,
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communicating realistic economic values for wildlife, especially nongame wildlife. Most people
will agree that wildlife outputs of the typical
forest possess value, but great differences of
opinion arise as to the relative amounts of such
values. Some approaches to evaluate wildlife
values have been made, yet a large measure of
intangibility always surrounds many of these values
(Clawson 1975). This puts managers at a decided
disadvantage because other forest resources
have easily defined and measured economic values.
Measuring wildlife outputs, assigning those outputs a value, and communicating those values
to decision makers are major problems facing
many agencies. A process is also needed to
assign values to habitat improvement work done
for wildlife. This type of infonnation will
facilitate management decisions, especially
where there are conflicts between wildlife and
other resources. This approach may not be the
best way to compare wildlife with other resources
because of the subjective nature of assigning
dollar amounts to most wildlife. A better
approach may be to start with the basic premise
that all species are integral to ecosystem
functions. Using recreation cash values, as
most agencies do, ignores that wildlife enhances
the quality of human life. It also ignores
the biological value wildlife has as part of
an integrated ecosystem. Recreational uses of
wildlife are easily defined but difficult to
measure.
NATIONAL FOREST MANAGEMENT ACT
The National Forest Management Act of 1976
poses several questions concerning wildlife
that must be dealt with in Forest Service land
management plans. Answers must be found for
questions such as: what are the best indicator
species for snags in different forest types;
what are the minimum habitat needs for snagdependent wildlife species; how can snag
habitat be provided over time in conjunction
with intensive timber management; how should
snags be distributed; how should snag-dependent
wildlife be monitored and what are stable
densities for snag-dependent species. The
requirements of this Act present substantial
management problems and provide major challenges
for research.
Understanding this relationship will help give
economic consideration to the basic functional
characteristics of the ecosystem in the decision
making process of land management agencies.
Since snag-dependent birds and mammals make up
a large proportion of the insectivorous, forest
dwelling wildlife population, it is important to
adequately reflect the relationship to insect
populations with realistic economic and biologic
values.
CREATING AND IMPROVING SNAG HABITAT
Cost effective methods for creating snag
habitat and/or improving habitat for selected snag
dependent species are becoming increasingly important. In the past, managers have been concerned
only with preserving existing snags. Finding w~s
to improve habitat for various wildlife species or
groups of species and how to create snag habitat
from live trees present research and management
with important challenges. Answers to these
questions will provide valuable management tools.
We may be faced with providing artificial
resources such as nest boxes, as a result of continuing habitat reduction from increasing demand
for wood products. This alternative may not be
the most appealing, however, it may be our only
recourse near urban areas or other areas heavily
impacted by timber salvage operations or fuelwood
use. While nest boxes may be a valuable management tool for some problems or problem areas,
boxes cannot be considered a total substitute for
snags. But the use of artificial nesting structures
is certainly deserving of additional research. We
need the baseline data now so applications can be
made when critical situations arise.
Meeting snag requirements over time is a
critical question facing resource managers today.
As timber management intensifies, there is a tendency to eliminate large trees that could become
snags. In addition, existing snags will be lost
through natural processes, and fuelwood activities.
This will reduce snag recruitment and result in
substantial reductions in snag densities. We need
management, policies and practices that will ensure
a sufficient number of quality snags to provide for
long-term survival and reproduction of snag-dependent wildlife species. A major challenge facing
all of us is to get consideration for wildlife
habitat.firmly ingrained into timber planning and
management.
ROLES OF SNAG-DEPENDENT WILDLIFE
The role of insectivorous, snag-dependent
birds in forest ecosystems is a major question
that has received some attention by researchers.
Of particular interest is understanding the
relationship of snag-dependent birds to insect
population dynamics. Many early works tended
to overstate the case and used simplistic
interpretations of birds controlling insect
populations (Thomas 1979}. Definitive data is
needed to illustrate the role that snag-dependent
birds and insectivorous bats play in holding
insect populations at endemic levels or exerting
some control during early stages of outbreaks.
ENERGY DEMANDS
The increasing demand for fuelwood poses a
particular threat to snag-dependent wildlife
species. Wood is becoming increasingly attractive
as an alternative energy source as the cost of home
heating increases. Fuelwood demand is increasing
as populations increase. This is already presenting critical management problems in some
areas due to illegal fuelwood harvesting. Fuelwood harvest was largely concentrated around
urban areas in the past but with increased demand,
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harvesting has increased in distant less accessible
areas. The projected increases in fuelwood demand
present a challange that we must meet while still
providing habitat for snag-dependent wildlife
species.
and usually in depth only about a species or
small group of animals. But we often lack
knowledge of habitat requirements related to
populations of wildlife (Cutler 1982) and the
role these populations pl~ in an integrated
ecosystem.
Land managers must begin to carefully analyze
fuelwood harvest alternatives based on a clear
understanding of the impacts on wildlife and the
long-term impacts on the forest. Snag management
and fuelwood management must be integrated into
timber management programs if we are to ensure
proper management of these two resources.
Along with public education goes an
increased need for enacting and enforcing of
fuelwood laws. Law enforcement is a basic
management tool. However, it has, in many
ways, been neglected in forest management by
land management agencies. We need to recognize
fuelwood law enforcement problems and take
appropriate action to allocate money and people
to carry out enforcement programs. History has
repeatedly shown us that public morality and
ethics cannot be legislated. However, enacting
realistic state fuelwood laws, establishing uniform
fuelwood policies, and strong enforcement of
fuelwood laws is critical to the continued existence
of snags on many acres of forested lands. Open
and continuous communications between enforcement
and management agencies, and research agencies
will contribute significantly to our ultimate
success.
PUBLIC EDUCATION
Illegal fuelwood harvest is a major management problem in many areas. Most people think
snags have no biological value. They can see
only the value of the wood for burning in fireplaces and woodstoves. We as researchers and
managers must convey to the public, including
private landowners, the importance of snags to
wildlife and to forested lands. We must change
public attitudes toward snag management. Although changing public attitudes through the
educational process is slow, its pursuit is
none-the-less important because historically
good forest management meant removing snags.
This is an important challenge that we must
pursue aggressively.
CONCLUSIONS
In many forested areas, timber management,
fuelwood activities, and fire prevention and
suppression activities are making snags a persecuted and endangered wildlife habitat.
Smokey the Bear has been an extremely
effective public education tool in Forest
Service fire prevention programs. Perhaps the
Forest Service should add a third mascot to
its public education team of Smokey and Woodsy
Owl. What better candidate for the job than a
nationally recognized figure like Wooqy Woodpecker?
The vul nerabi 1i ty of snags makes snagdependent wildlife equally vulnerable.
If snag-dependent wildlife species are to
remain as part of the managed forest,
forest managers must provide the necessary
habitat. (Thomas 1979)
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Although there are differences in detail,
most of us can agree on a number of basic principles of snag management.
Public education is a difficult process
made even more difficult by the fact that,
before completing high school, most of our
personal traits have alreadY been formed (Hamilton
1982). There is ample evidence that our education
system has thus far failed to develop a conservation ethic or understanding (Hobart 1972).
We must make wildlife and other natural resource
subjects a part of the K-12 curriculum. Natural
resource material is being developed and used
in some states (Hamilton 1982). We need to take
a more active role in dissemination of this
material. Long-range education programs must
build solid foundations for understanding
resource management. An awareness by the
public of man's dependence upon, and responsibility
for, natural ecosystems and an understanding of
the values of wildlife are critical to long-term
resource management and conservation. Conservation
education must build an ethical underpinning
for land economics and a universal curiosity
to understand the land mechanism. Conservation
m~ then follow (Leopold 1953).
1. Manage for the total ecosystem of
which snags are an intregal part.
2. Through research, establish a basic
understanding of the ecological, social and
economic aspects, not only of snag-dependent
wildlife, but of all wildlife.
3. As professional resource managers and
researchers work towards establishment of conservation and resource education programs.
4. Make wildlife policy decisions based
on public interest and sound ecological principles, not just on special interests.
5. And finally, "spare that old dead tree,"
or, "what we need around here is a little more
dead wood.n
Biologists too need to be better educated
in ecosystem management. Most biologists a~e
well-versed in the biological details of an1mals,
225
LITERATURE CITED
Clawson, r~arion. 1975. Forests for Whom and
What For? The John Hopkins University
Press, Baltimore, ~10. 175 pp.
Leopold, Aldo and Luna Leopold. 1953. Round
River: From the Journa l s of Aldo Leopold .
Oxford Univ. Press, Inc., N.Y. 173 pp.
Cutler, M. Rupert. 1982 . What Ki nd of Wildlifers Will be Needed in the 1980's?
Wildl. Soc. Bu ll. 10(1):75-79.
Scott, Virgil E, Keith E. Eva ns, David R. Patton
and Charl es P. Stone. 1977. Cavity-Nesting
Birds of North American Forests. U. S.
Department of Agriculture Handbook, 511,
112 p. Washington O.C.
Hamil ton, Clifford R. 1982. Project Lea rning
Tree and Project WILD, Resource Models
for Education at the Elementary and
Secondary Levels. Trans. N. Amer. Wildl.
and Natur. Resour. Conf. 47:248-251 .
Thoma s , Jack Ward, ed. 1979. Wildlife Habitats
in Managed Forests, the Blue Mountains of
Oregon and Washington . U.S. Department
of Agriculture Handbook 553, 512 p.
Washington D.C.
Hobart, W. 1972. What's Wrong With Conservation Education?. J. Environ. Ed.
3(4) :23-25.
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