Forest fires not all bad, says forest researcher

by Stephen Forgacs
Staff writer

Forest fires that sweep the province after a long dry period play an important role in maintaining ecosystems and ensuring the survival of certain plants and animals, a UBC Forest Sciences professor says.

Each year, thousands of hectares of forest and grassland in the province go up in smoke. As of last week there were more than 500 forest fires burning in B.C.

But for generations of Canadians who grew up hearing the U.S. Forest Service's Smokey the Bear say forest fires were bad, television images of raging fires leave impressions of devastation.

"Smokey the Bear made people feel that fire was strictly the enemy of the forest. It killed animals, destroyed trees and plants, caused soil erosion, and fouled streams," says Assoc. Prof. Mike Feller. "Fire does have a negative impact, but it also has positive effects which are very much part of the natural ecological cycle."

Certain trees and plants rely on fire to provide conditions for germination while animals such as deer and elk thrive on the vegetation that grows on burned sites, Feller says.

Feller has studied the effects of forest fires for years, in particular their impact on nutrient cycles, but has delved into a range of other issues as well.

Both his and other researchers' findings suggest that, after years of adhering to a policy that directed efforts be made to fight every forest fire in the province, the B.C. Forest Service's move to a more selective approach to fighting fires makes sense in both dollars and ecology.

Feller says most North American jurisdictions now assess fires based on factors that include risk to human life, property, timber supply, recreation and wildlife. The weight that is placed on factors depends on regional economies as well.

"In the Canadian Arctic we expend resources fighting fires that threaten the habitat of fur-bearing animals, such as marten, to protect the local economy," he says.

Among the ecological factors that should be considered in forest management policies, says Feller, is the importance of early successional conditions, which occur in the period immediately after a forest fire when vegetation re-appears.

This period provides food for deer, moose and elk, which eat low-lying shrubs, grasses and flowers -- plants which disappear as the forest grows and prevents sunlight from reaching the ground.

"Without fire, you would have fewer early successional plants, and far fewer of these animals," says Feller.

Certain plants, such as the flower Corydalis sempervirens, will germinate only after being exposed to the heat of a fire and require strong sunlight to grow.

Trees, such as lodgepole and jack pine, also rely to a certain extent on the heat of fire to open their cones and permit germination.

Efforts to simulate natural disturbances such as fire through clearcutting and other forest management practices have met with only limited success, says Feller. He points out that forest fires tend to leave a natural mosaic of burned and unburned forest, and that even a severe forest fire, in which temperatures can reach 700 to 800 degrees Celsius, will leave some vertical trees that play a role as wildlife habitat.

Feller has also found that while nutrient loss from soils as a result of forest fires can have serious implications in some alpine regions in the interior of the province, nutrients in coastal regions are quickly replenished.

"Air pollution does wonders in replacing nutrient values lost by fires on the coast," he says.