Scientists: Science-based management, fire-resistant homes can offset wildfires
After wildfires flared up this summer across a drought-stricken West, some frustrated Americans want to see agencies doing things to reduce the threat. But as a National Forest Foundation panel revealed, the most effective actions aren’t what some expect or want.
On Monday, the National Forest Foundation hosted an online panel of fire experts to discuss how fires burn - especially during the more extreme conditions caused by climate change - how different forest projects are affected, and what that means for forests, communities and air and water quality.
Of the three factors contributing to wildfire – topography, weather and fuels – the factor that man can manipulate the most effectively is fuel, said panel moderator Colin Hardy, formerly of the Forest Service Fire Sciences Lab in Missoula. That’s why agencies focus on tree thinning projects – the less fuel, the less likelihood of fire. Research has shown that taking some of the trees out of dense forest stands can reduce the intensity of a future wildfire because the fuels have been reduced.
However, few of those projects were helpful in reducing this summer’s wildfires. In the Northern Rockies, almost 3,800 fires burned about 1 million acres, according to the Northern Rockies Coordination Center. Almost three-quarters of the fires were human-caused.
Meanwhile, the Forest Service has continued to put out 98% of the wildfires that start, instead of letting a few burn to clear out debris.
“Our recent wildfires are telling us an awful lot about what works and what doesn’t,” said Fire Lab scientist Mark Finney. “They’re telling us the current practices, whatever we’re doing, are not protecting our wildlands, our watersheds, our timber, our habitat, our recreational values.”
Finney said science shows that thinning doesn’t go far enough. To maximize fuel reduction, including the elimination of ground fuels like shrubs, grasses and downed wood, prescribed burning is essential to bring down the wildfire risk.
Foresters recognized that need 50 years ago, when they started acknowledging that the Forest Service policy of full wildfire suppression, begun in the early 1900s, had disrupted the natural fire regime that evolved over centuries, so forest fuels built up.
Prior to about 1900, wildfires – started randomly by lighting or purposefully by Native Americans - moved through some Western forests two or three times a decade. The result was healthier forests with less vegetation fueling smaller wildfires.
Southeastern U.S. forest managers have taken those lessons to heart, because they’ve regularly use prescribed burns, unlike managers in the West. That needs to change, Finney said, because science shows the use of fire is essential to reduce wildfire risk in the seasonally dry forests of the West.
For example, the 2002 Rodeo-Chediski Fires in Arizona burned unabated through areas that had been commercially logged and only dropped down in portions that had recently been burned.
However, the other thing science shows is one forest stand is too small to make much of a difference, Finney said. Larger landscape-scale planning and changes are needed, because some of the megafires can burn almost a million acres. So, if conditions are moderate, maybe some wildfires should be allowed to burn to help get rid of fuels, Finney said.
“In the West, despite the policy changes, we don’t have a science-based approach to managing fire. We’re dominated primarily by emergency response and suppression. This is pretty much all tactical; it’s not strategic in any way,” Finney said.
U.S. Forest Service Portland NIMO Incident Commander Barbara Day said depending on emergency response and suppression was becoming a risky thing to do. Incident Management teams are not only getting smaller but they’re also under a lot more pressure as more people move into fire-prone areas, more wildfires spread across the West, and the fire season now lasts throughout the year.
Forest Service retirees who used to serve in incident command teams are aging out and the ones who remain can’t go out on fires all year long. Last year, COVID-19 just made matters worse, Day said.
“Expectations have been raised over years of suppression,” Day said. “(Teams) have done a great job of trying to protect all those values, and an expectation has developed. So, we have to make sure those expectations are realistic. And I think it’s getting harder and harder to do that.”
Former Fire Lab scientist Jack Cohen said a lot of the pressure could be taken off firefighters if worries about the loss of houses or communities could be separated from the need to manage forests and wildfires. And it can, because Cohen’s research shows that many homes burn because of the fuels attached to and within 100 yards of a house, not the fire. Meanwhile, wildfires sometimes need to be allowed to burn.
“We’ve got two different issues here. The long-term results have to do with the management of our landscapes with regard to fires and appropriate ecological processes, and houses are getting in the way. The community threat is getting in the way,” Cohen said. “The science indicates we can separate those. If we look at a community as a cluster of home-ignition zones, it doesn’t change the physics of the problem, it changes the social dynamics.”
In the aftermath of several fires, Cohen found that some houses survived untouched as fire burned around them, while elsewhere, complete neighborhoods burned to the ground even though the fire wasn’t even close. Most of the houses in the neighborhoods were covered with leaves or pine needles and exteriors that weren’t fire resistant. Windborne firebrands would start fires on one or two houses, which could then contribute to fires in nearby houses. The chain reaction reaches the point where firefighters are overwhelmed, and disaster results.
Conversely, the homes that survived had fire-resistant roofs and siding. This is also why homeowners are asked to clear trees and vegetation – the fuel - around their homes to maintain “a defensible space.” But a fair number of homeowners don’t do this, just like many private property owners don’t manage their forests. Until they do, it will be difficult to restore the West’s proper fire regime, Cohen said, and firefighters will continue to face unsafe conditions trying to save unsafe houses.
“The wildland-urban fire problem is not a problem of wildfire control,” Cohen said. “The most effective treatment, whether it’s in the wildland or the community, is the fuels treatment. And when it comes to communities, the community is where we need to change the results of the fire. So, having ignition-resistant homes means preventing wildland-urban fire disasters.”
Contact reporter Laura Lundquist at firstname.lastname@example.org.