Penn State Live - Looking at forest fires in a whole different way

Looking at forest fires in a whole different way

Wednesday, June 3, 2009

University Park, Pa. — Smokey Bear has been telling Americans since 1944, "Only You Can Prevent Forest Fires," but a new bill under consideration in the state's General Assembly may begin to change Pennsylvania's approach to the blazes, according to forest experts in Penn State's College of Agricultural Sciences.

"A common misconception of the general public is that forest fires are destructive," said Marc Abrams, professor of forest ecology and physiology in the School of Forest Resources. "Unlike the intense crown fire that burned Yellowstone Park in the 1980s or the recent, intense fires in the pine forests of the Southeast, fires in the northeastern United States are typically of low intensity and are not destructive."

Under current Pennsylvania law, people can be held criminally liable for burning activities, even when it is with good intention. If passed, the bill would encourage the proper use of burning as a land-management tool by setting stricter standards to regulate burning practices and ensuring that involved parties who obey the law are not held liable, said Marc McDill, associate professor of forest management.

Burning is an important tool for managing forests, wildlife and grasslands because it can improve habitats and help to maintain the ecological integrity of an area, Abrams explained. The practice, dating back thousands of years, is based on a natural occurrence that cleans out barrens and other scrubland to prepare for new plant and animal life.

"In fact, the vast majority of forest types and grassland evolved with frequent fire, and most species are adapted to benefit from periodic, low-intensity burning," Abrams said.

"Burning was used frequently to manage forests, dating back 5,000 to 7,000 years ago when Native Americans inhabited this area," Abrams said. "Burns were conducted to control pests, such as snakes and insects and to promote the growth of species such as oak, hickory and chestnut, which offer beneficial mast and nut production that sustain wildlife."

By the late 19th century, European settlement had interrupted this practice, and as fires increasingly became dangerous conflagrations fueled by slash left over from logging, the mentality of burning fell out of favor, Abrams noted. The Smokey Bear campaign, launched in 1944, continued this philosophy.

"Looking at northern and southern Pennsylvania separately, fire in the southern part of the state has always been a part of the natural disturbance regime, and this is true to a lesser degree in the north," McDill said. "If you take fire out of those ecosystems it can have cascading effects."

The absence of frequent fires changes the species composition and structure of forests. Oak, hickory and chestnut, once common species in Pennsylvania woods, are adapted to thrive in an ecosystem where fire happens frequently. Without regular fires to control the growth of other species entering the ecosystem, oaks get out-competed by species such as red maple.

"Right now most of our oak forests throughout Pennsylvania are changing in composition because of out-competition resulting from the last 70 to 80 years of fire suppression," Abrams said.

This shift away from oak and other fire-adapted trees to red maple affects the entire ecosystem. Oaks produce acorns during the fall that provide a valuable winter food source for turkeys, deer, squirrels and other wildlife. Red maple also produces abundant seeds, but this production occurs in the springtime when the demand for food is less urgent. "If a forest loses its oak component, the capacity to support wildlife decreases," explained McDill.

Controlled burns also help to manage natural fuel loads of dried leaves and twigs that accumulate on the forest floor, which can increase the risk of uncontrollable wildfires, especially in drier areas in the western United States. Decades of fire prevention and suppression can result in much higher fuel loads than natural, McDill pointed out. Prescribed burning can enable forest managers to decrease risks before these fuel loads spark emergency situations.

The risk that fire will go beyond planned boundaries is always there, but unlike the western part of the country, Pennsylvania is particularly wet. "These conditions and the proposed guidelines will ensure that the risk of fire extending beyond planned boundaries is very low," McDill said.

Those same strict guidelines offer a very small window of opportunity for burning, amounting to several weeks in the spring and perhaps one in the fall. "It's unlikely that we will ever be burning more than a couple thousand acres a year across Pennsylvania," McDill added. "Fire can be a really useful tool, and it's already widely used in the southeastern and western parts of the country, where laws like the one being considered here are already in place."

"We hope the new legislation will point Pennsylvania in the right direction for increasing the use of fire as a management tool," Abrams said.