Wildland fires, such as those currently blazing through Arizona and scorching numerous other areas in the nation, play a "vital role" in the ecological health of the regions in which they burn. They're part of the natural cycle of life on the planet, but they can become conflagration disasters when they damage homes and run into populated areas.
At a National Fire Protection Association program in Boston on Monday, two NFPA staff members talked about the cycle of wildfires, their benefits and drawbacks and what can be done to keep humans and nature in harmony.
Molly Mowery, associate project manager of NFPA's Firewise Communities program, said that despite the destruction we've all seen caused by wildland fires, we need to keep in mind that fire also helps create "healthy eco-systems" by clearing dead vegetation and adding nutrients to the soil.
"Fires are a normal part of nature," Mowery said during a presentation called "Flames in the W/UI: How Wildfire Mitigation Planning Can Minimize Risk to People and Property."
"...They happen in all parts of the country and they happen year-round."
Wildland/Urban Interface History
The problem lies in the wildland/urban interface, or as Mowery and her associate Michele Steinberg, manager of the Firewise Communities program call it, the "WUI."
"When the natural cycle of fire comes in contact with houses and property, it becomes a disaster," Steinberg said.
The natural tendency is to extinguish fires and in 1910, the U.S. Forest Service adopted an "out by 10 a.m." policy of extinguishing all fires by the next morning, Mowery said. That policy, which has since been repealed, was a reaction to a devastating fire that claimed more than three million acres in the Northwest, particularly Idaho and Montana.
That policy left lots of fuel load in the forest and thwarted nature's cycle, creating even more potential for fire in subsequent fire seasons, Mowery said.
Compounding that problem was the migration of the population to areas that are prone to wildland fires, like Arizona, which put more property and homes in the paths of the cleansing fires, Steinberg said.
In 1961, a study was conducted of the Bel Air-Brentwood fire in California, Steinberg said. That fire, according to records, claimed more than 6,000 acres and nearly 500 homes.
Steinberg said scientists studied the fire patterns and why some homes were spared and others flattened. It was apparent that homes that survived were made from non-combustible materials and had no vegetation around.
That pattern was observed again in a study called the "International Crown Fire Modeling Experiment" in 1998, Steinberg said, noting that researchers lit fires and studied the effects they had on wooden walls. As what would seem to be common sense, the closer the walls to the fire, the more charring and ignition incidents, she said.
It was determined that being 33 feet from a tree on fire might produce heavy charring, but no ignition, Steinberg said, noting that at twice that distance, 66 feet, there was no charring or scorching. Hence, the first concrete effects of mitigation were documented, she said.
Mitigation and Education
In the intervening years, organizations like NFPA have been advocates of non-combustible materials for homes in wildland fire-prone areas and of clearing of vegetation to help prevent fires from becoming conflagrations, Mowery said.
Mowery said that there's a tendency to want to leave as much vegetation around homes as possible, especially those homes constructed in the interface areas.
"That's why people build in those areas, they want trees around them," she said.
Education is the key to helping people understand the importance, or more importantly, the value of wildland fire mitigation, Steinberg said.
That's why programs like NFPA's Firewise are successful in taming the wildland/urban interface fires, she said.
Through teaching land planners, contractors, community civic groups, firefighters and individual home owners the benefits of mitigation and how to do it, property is saved, Steinberg said.