UNIVERSITY PARK, Pa. -- Widespread drought in Pennsylvania -- combined with the annual shower of colored leaves and twigs -- are making forests particularly flammable this fall. The wildfires flaring up across the state -- although unfortunate -- serve to illustrate the important role "prescribed burning" can play in forest management, says a forest ecologist in Penn State's College of Agricultural Sciences.

"For thousands of years, fire played a normal -- and beneficial -- role in forests in the Eastern United States," says Marc Abrams, professor of forest ecology and physiology. "Fires moved through the understory of oak and pine forests every five to 10 years, burning up excess fuel, eliminating weedy species and helping to create the healthy forests we have had historically.

"But as a result of fire suppression practices started in the early 1900s, fuels have built up to unnaturally high levels," he says. "Today's fires are hotter and more destructive -- and they're killing more trees. The lack of regular fire also is having a profound impact on forest composition. In particular, we have seen a dramatic increase in red maple, birch and cherry."

Abrams supports the use of "prescribed burning," in which experienced foresters start, control and end fires as a forest management tool. "Historically, American Indians used fire to encourage the growth of trees that produce food for wildlife," he says. "Fires also started naturally, from lightening strikes."

A 2,700 acre wildfire burned recently near Pine Creek in Lycoming County. Two others -- one covering 300 acres and another consuming 350 acres -- erupted in the Moshannon State Forest, as did one in the Michaux State Forest and one in a forested area north of Harrisburg.

The fires aren't limited to Pennsylvania. The drought has been blamed for the worst outbreak of forest fires in the Appalachians in a decade, including 150,000-acre burns in Kentucky and the Smoky Mountains.

Pennsylvania's Department of Conservation and Natural Resources, Game Commission, and Fish and Boat Commission all banned open fire on their lands, and recommend extreme caution. The Game Commission also issued a smoking ban.

"Western forest fires get most of the press since they're more flammable and catastrophic," Abrams says. "Predominantly evergreen, western forests tend to burn as 'crown fires,' or 'stand-replacing fires.' To some extent, it's expected out there that fire will burn through the crown, kill the existing trees and allow a new forest to develop.

"Our situation in the East is different. Most of our deciduous forests historically burned as low-intensity, understory fires. These fires kept the forest in an 'oak and pine successional phase' by eliminating competing species, reducing litter and exposing the mineral soil. This stimulated acorns to germinate and grow in the understory."

Because fuel loading has grown quite high, Abrams explains that we may get mixed results in the beginning from prescribed burning. We may get the desired effects in some stands, but others may burn too hot -- until an equilibrium gets established.

"In the East, we must learn to think about the beneficial effects of using fire in our ecosystem management practices," he says. "If we don't, we can anticipate a large decline in oak and pine populations from the present levels."

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EDITORS: To contact Marc Abrams, call 814-865-4901.

Contact:

Kim Dionis kdionis@psu.edu 814-863-2703 814-865-1068 fax