One of the most important management tools in restoration
ecology is fire.
Fire is a natural element in the ecosystem, and under appropriate
conditions may develop spontaneously as a result of lightning
strikes. Lightning-caused fires occur mainly during warm windy
dry conditions and hence occur rather randomly. However, tree
ring studies have shown that most oak savannas were burned
at 10-year or more intervals.
Imitating nature, humans throughout the world have used fire
for thousands of years. In North America, fire was used by
Native Americans to encourage berry production, expose acorns
for collection, prepare planting sites, control undesirable
pests, fireproof villages, create and maintain open woodlands
and savannas, concentrate game, and help maintain trails.
Fires were ignited either in spring, before plants had started
to grow, or in fall, after frosts had killed above ground
parts of plants.
When European settlers displaced Native Americans, the use
of fire continued, for many of the same reasons. In the hill
country of southwestern Wisconsin, farmers continued to use
fire to keep grazing land from getting choked with brush and
weeds. Early spring burns encourage the growth of grasses
by removing detritus and debris, and by top-killing shrubs.
However, by the late 19th century, widespread logging left
vast acreages with dried slash that ignited easily and burned
with unusual power, creating landscapes prone to dangerous
high-intensity wildfires. State laws related to wildfires
were enacted to prevent damage to the land and to humans.
In the early 1900s, the newly established U.S. Forest Service
began a major campaign to control forest fires. "Smoky
the Bear" was created as an icon of fire suppression.
All of these activities had unintended consequences, destroying
the values that the oak forest provided, and replacing the
oaks with undesirable trees and shrubs.
Fire was reintroduced into the Upper Midwest as a management
tool in the 1940s by John Curtis and associates during their
work on the establishment of new prairies at the University
of Wisconsin-Madison Arboretum. The demonstration of fire’s
utility led to a gradual increase in the use of fire throughout
the region.
Prescribed Fire
The term "prescribed fire" refers to fires that
are set on purpose according to a written and approved plan,
the prescription. The plan describes the objectives of the
burn and the expected results. The burn plan specifies, either
in words or by a map, the parcel of land to be burned, the
landowner(s), and owners of adjacent land not included in
the burn. Any considerations of smoke management are identified.
The burn plan specifies the required governmental permits,
and lists those who must be notified on the day the burn is
to take place. The locations and characteristics of all fire
breaks are given, as well as strategies for containment of
fire within the burn unit. Any preparations of the burn unit
needed before the burn can take place are indicated, including
a list of fire sensitive elements within or near the burn
unit that must be protected. The burn plan should state the
personnel needed, as well as their qualifications and duties.
The burn plan also lists the equipment needed to conduct the
burn.
In Wisconsin, prescribed fire is now a critical management
tool for organizations such as The Nature Conservancy, The
Prairie Enthusiasts, Pheasants Forever, and the Wisconsin
Department of Natural Resources. Many private landowners also
use prescribed fire on a regular basis. The U.S. Department
of Agriculture, through its Natural Resources and Conservation
Service, strongly promotes the use of prescribed fire in management
of private lands that have been dedicated to various soil
and water conservation programs. The Wisconsin Prescribed
Fire Council strives to make the use of fire in Wisconsin
safer and more accepted. A number of commercial contractors
carry out prescribed burns for landowners.
Since the early 1970s there has been a gradual reintroduction
of the use of prescribed fire. Even the forest industry now
realizes that in the oak forest fire plays a major role in
removing many weedy trees and shrubs. Prescribed fire removes
the thin-barked shrubs and trees from the midstory and understory
of the forest without harming the dominant oaks. Fire also
consumes the litter, thus promoting the growth of grasses
and forbs, and encouraging the regeneration of oak. Long-term
research studies have shown that annual burns over a number
of years gradually restore the oak savanna to its original
state.
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