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While the fires blaze, the focus is on the scale of the fire…thousands of acres burned, where are the fire lines, what are the risks? After the fire, society tends to focus on "effects." What is the impact on soil and accelerated erosion scenarios as the rains return to the Los Alamos area after the fire of 2000? What will be the impact on streams and fish populations?
During the fires of 1988 in the Yellowstone region, much media attention was given to impacts on wildlife. How many bison died? How will the fire affect their winter range?
From the broad citizenry perspective, it is natural to relate the broader questions of impact or effect on water, plants, and animals–those more tangible elements of the ecosystems. To answer these questions though the wildland fire communicator needs an authoritative source to which to turn.
The National Wildlife Coordinating Group's (NWCG) publication Fire Effects Guide provides an in-depth review of the multiple effects of fire. This edited document provides a concise background on the ecological and physical science related to aspects of fire that can help guide message development.
The Fire Effects Guide is divided into twelve chapters:
These sections are supported by an extensive glossary and bibliography on fire effects. Understanding each of the twelve sections presented is critical to understanding and formulating a comprehensive and cohesive message for your audience or for others such as the media. These groups expect the communicator to translate the science behind the fire into language and concepts that relate to their realm of understanding.
For example, if you are interpreting the long term impacts of the Mesa Verde fire of the summer of 2000, all twelve sections presented are relevant to building a cohesive story. You cannot discuss cultural effects, such as the trade-offs between degradation of some structures and artifacts and the uncovering of others, unless you also discuss ecological effects.
To provide you with an overview of the Fire Effects Guide contents, the following chapter titles, their author(s), and edited summaries from the document are provided.
Author: Tom Zimmerman
Land management programs are objective driven. Objectives must be based on an
amount of information sufficient to determine if a change from the present condition
to the proposed condition can be achieved. Establishing objectives is a task
of major importance and deserves an allotment of sufficient attention and time.
Both objectives and fire effects information become more precise as site specificity
increases.
Chapter II–Fire Behavior and Characteristics
Author: Melanie Miller
Knowledge of the behavior and characteristics of wildland fire is important
both for managing fire and for understanding and interpreting the effects of
fire. The heat regime created by a fire varies with the amount, arrangement,
and moisture content of flammable materials on a site. Trained and experienced
people can predict (within a factor of two) some aspects of the behavior and
heat release of a flaming front of a fire, and some associated fire effects
such as crown scorch. However, many fire effects are related to characteristics
of fire that are not related to the behavior of the flaming front and cannot
presently be forecast.
| Fire Effects Guide (NFES #2393) is available from: National InterAgency Fire Center Attn: Supply 3833 S. Development Ave. Boise, ID 83705 http://www.nwcg.gov/pms/pubs/catalog.htm |
Author: Melanie Miller
Fuels are an integral part of most wildlands. At some time after death, or while
still alive, all vegetation becomes potential fuel. The single most important
factor controlling the flammability and consumption of fuels is their moisture
content. The moisture content of dead wildland fuels is regulated by environmental
factors, while that of living plants is largely controlled by physiological
processes. Other fuel properties can also affect the degree of consumption.
All direct effects of fire result from the characteristics of the heat regime
of the fire, which is controlled by the manner in which fuels burn. Management
of fuels is important because by doing so, the heat regime of a fire is also
regulated.
Authors: Larry Mahaffey and Melanie Miller
The effects of smoke on health, air quality, and regional haze are very important
to all land managers. They must recognize the need to manage smoke from wildland
fires using the best available control measures. Every manager must determine
the level of smoke management necessary to provide the least impact on the public,
both in terms of health and visibility. The effects of smoke on firefighters
also must be considered when managing wildland fires. If federal agencies do
not take a rational, voluntary approach to smoke management, a man-datory approach
may be provided that makes it more difficult to meet resource management goals
and objectives.
Author: Bob Clark
The effects of fire on soils, water, and watersheds are extremely variable.
In some cases, such as accelerated erosion, the outcome is reasonably predictable
and mitigating measures such as rapid revegetation are necessary. In other cases,
such as change in off-site water yield after burning, the outcome is much less
predictable because it appears to depend on site-specific characteristics and
on unpredictable climatic events. The application of mitigating measures must
be based on local experience and local research. In almost all cases, the establishment
of a local database would provide useful information for future events.
Authors: Melanie Miller and Jean Findley
Plant response to fire is a result of the interaction of the behavior and characteristics
of a fire with the characteristics of a plant. Plant community response is a
product of the responses of all plants on a burned area. The response of an
individual species of plant or plant community can vary among fires or within
different areas of one fire. This is because of variation in fuels, fuel moisture
conditions, topography, wind speed, and structure of the plant community itself,
causing the heat regime of a fire to vary significantly in time and space. The
immediate effects of fire can be modified by postfire weather and animal use.
Fire can cause dramatic and immediate changes in vegetation, eliminating some species or causing others to appear where they were not present before the fire. Monitoring techniques that are used to detect trends in vegetative communities are often not appropriate, either because they are not sensitive enough to detect the changes that have occurred, or they provide statistically inadequate samples. Fire effects on plants and plant response to fire treatments are predictable if the principles and processes governing plant response are understood. If burning conditions, fire treatment, and vegetation response are properly monitored, the fire effects that are observed can be interpreted, and our ability to predict fire effects on plants will increase.
Author: Loren Anderson
Fire is a shock–frequently, nearly instantaneous–to the ecological
setting involved according to authors cited in this chapter. Some wildlife species
are able to adapt to the rapid change in environment and some cannot. The habitat
for some species is greatly improved, while for others it may be degraded if
not eliminated, and there will be endless variation in between. No fire–either
wild or prescribed–is uniformly "good" or "bad." Effects are differentially
imposed.
Fire effects on wildlife and wildlife habitat revolve around successional theory. Habitat structure tends to follow successional trends in most plant communities. Fire event intervals play a significant role in these trends.
Faunal succession tends to follow floral succession but they do not uniformly correlate. To understand effect, a series of questions must be asked.
Addressing the overall effect of fire on wildlife for a given area that has burned is most easily approached by going from the general to the specific, e.g., as illustrated by the following questions:
A righteous attempt at providing for desired fire effects through prescribed burning or evaluating wildland fire effects on wildlife and its habitat requires an integrated effort of disciplines. An appreciation of the historical perspective can be invaluable. Contributions by plant and fire ecologists are essential. Postburn management is absolutely critical. Obtaining good management necessarily requires close coordination with and commitment from specialists in range, forestry, recreation, and others. Without adequate monitoring and evaluation, little knowledge can be gained, and even less shared.
Author: Richard C. Hanes
Damage to cultural resources posed by wildfires and prescribed fires can be
severe, ranging from chemical alteration of cultural materials to exfoliation
of building materials and rock art panels. However, almost all impacts can be
avoided through advanced planning. Protective measures can include removal of
high fuel loads by hand or prescribed fire, careful use of fire breaks for avoiding
fire effects on wooden structures and other highly susceptible resource values,
and use of archaeological monitors on wildfires in sensitive areas to avoid
fire suppression damage.
The experiments and observations thus far conducted indicate that cultural materials below the surface, unless directly exposed to a burning duff layer or burning underground roots, normally do not sustain significant damage, if any at all according to research cited in this chapter. Ground surface temperatures have been documented in excess of 800° F (427°C), but only 100°F (38°C) at 2 inches (5 centimeters) below the surface. Obviously, the magnitude of fire effects on the soil and its contents is proportional to heat penetration. In conifer forests, for example, temperatures of 200°F (93°C) have been recorded 0.5 inch (1.3 centimeters) deep in the soil, with duff layers considerably above that figure. Obviously, such heating depends on the thickness of the duff layer, duff moisture content, amount and moisture content of large diameter dead woody fuels, and soil type and its moisture content. Given current knowledge of fire effects on cultural resources, it is apparent that fires involving larger fuel loads, longer duration burns, and large total heat release pose significantly greater hazards to cultural resources than fires with short duration "cool" combustion temperatures.
Author: Ken Stinson
Proper site management based on specific objectives and plant species is essential
in the management of fire effects. Improper grazing management can easily nullify
efforts put into prescription burning or wildland fire rehabilitation, as well
as impede natural vegetative recovery after a fire. Impacts of long-term grazing
management before and after a fire can be easily overlooked; therefore, proper
grazing management including the appropriate kind of livestock, the stocking
rate, the season and the intensity of utilization, and the length and frequency
of use are most important. The period of nonuse by livestock necessary after
a fire varies considerably with the vegetative composition, site conditions,
resource conflicts, and objectives of the burn. Grazing closures apply to all
fire sites, whether they are artificially reseeded or recovery is by natural
means. In some situations, the only way to ensure nonuse of critical areas after
a fire is to construct fences. Proper grazing management before and after a
fire has a major impact on fire effects, vegetation changes, economics, and
rehabilitation success. In analyzing fire effects, several site selection criteria
should be considered, including the site potential, the ecological condition,
the presence of desirable and invader plant species, the acreage of burn within
the management unit, and the livestock management. The consideration and implementation
of these factors determines the benefit/cost ratio and the success of a burn
project or postfire rehabilitation effort.
Authors: Ken Stinson and Melanie Miller
Evaluation of both monitoring data and the impacts of postfire activities must
be conducted in order to ensure that lands receive the best possible fire treatment,
rehabilitation, and postfire management. Once we have monitored and evaluated
enough projects and management actions on similar sites, and adjusted our actions
based on these results, we can become more confident that the proper treatment
is being implemented. The same degree of monitoring and evaluation need not
be carried out on all subsequently treated areas if vegetation type, soil type,
and treatment prescription are similar to that of other successful treatments.
However, it is professionally unacceptable to conduct no prefire or postfire
monitoring or site observation, to assume that an area is ready for grazing
because the designated length of time has passed since the occurrence of fire,
or to conduct no evaluation of the implementation or effectiveness of postfire
site management in preserving or enhancing site quality. Without some check
on the results of our activities, accumulated assumptions can lead to land treatments
that do not meet resource management goals and objectives, and lead to deterioration,
instead of enhancement, of site quality.
Author: Robert Clark
Statistical analysis of data and interpretation of results are helpful for understanding
fire effects and provide an essential tool for the decision-making process.
Calculation of the appropriate sample size is essential, and is based on desired
precision and confidence levels. The t-test for paired plots and chi-square
analysis of counts, are particularly useful for understanding fire effects.
Other, more sophisticated techniques may require the assistance of a statistician.
Author: Melanie Miller
Computer technology and applications are developing so quickly that any list
of software is incomplete as soon as it is published. Specialized computer programs,
called expert systems, may be available in the next few years. Expert systems
are being developed or planned that can assist in the development of fire prescriptions
to meet specific resource objectives, and to achieve specific fire effects.
Agency fire management and air quality specialists can be contacted for information
about future computer software development.
Collectively, this and similar documents and a plethora of information now appearing on the World Wide Web, provide the wildland fire communicator with the scientific basis necessary to formulate messages that reflect the best science and management to date.