Searching for the true causes of the West’s fire problems
By now we’ve all heard -- oh, how often have we heard --that a century of fire suppression has created a buildup of fuels that threatens an inferno across the forests of the West.
Forest Service officials, once happy to pose for photos with Smokey Bear, now give grim news conferences to announce that natural fire regimes are terribly unbalanced and that only massive "fuels reduction" can retrieve "forest health." Under the business model promoted by the Bush administration, such fuels-reduction projects are generally paid for by cutting trees large enough to be profitable for the timber industry.
To many, that seems like a reasonable trade-off, since we want to fire-proof our forests for the long term. But before we embrace this vision of logging our forests back to health, let’s examine its basic assumption: Is unnatural fuel buildup really causing more severe fires?
Like all seductive oversimplifications, the idea that fire suppression has created a tinderbox in the West’s public forests has elements of truth. It’s true that federal firefighters have been extraordinarily successful at keeping fire out of most Western forests for decades. It’s true that fuel loads are high in many places as a result, particularly in ponderosa pine forests that evolved with frequent surface fires. Most obviously, it’s true that fire cannot be kept off the land forever: Sooner or later, flammable fuels will burn.
But there’s a problem. According to the fire-suppression hypothesis, the longer it’s been since the last fire, the more fuel buildup and the worse the next fire. It’s like one of those notoriously clear relationships --simple, clear and wrong.
A meticulous new study in the Klamath Mountains of northern California-- by Dominick DellaSala of the World Wildlife Fund and others -- has shown that when fire does come, forests that have not burned for a long time burn with lower intensity than more recently burned forests. What’s more, tree plantations experienced twice as much high-intensity fire as did multi-aged forests.
That’s right: Young stands, whether created by logging or by stand-replacement fires, are more flammable than forests full of big old trees. This really shouldn’t come as a surprise. When you’re getting a campfire going, do you toss on some kindling or a two-foot-thick log?
This research shows the folly of logging big trees to reduce fire risk. In many forests, such an approach is likely to increase the severity of fires. The study also points out an obvious but too-often overlooked reason for our current fire problem -- past logging activities. Over the last hundred years, our biggest impact on the forests of the West has not been fire suppression. It has been the elimination of over 80 percent of old-growth trees by logging. What remain are younger stands with smaller trees and more brush -- exactly the sort of forests that are the most flammable.
Any experienced firefighter will also tell you that both the behavior of individual wildfires and the severity of fire seasons are driven by one factor above all -- weather. Large-scale atmospheric patterns that bring low rainfall and high temperatures are far more important in producing major fire years than is the biomass of fuel present, which varies little on an annual basis.
There has been an increase in severe weather events over recent decades, which many experts believe is a consequence of human-caused global warming. If this is the case, the bad fire seasons of the past 10 years may pale in comparison to what’s coming. What is our government doing to address carbon dioxide emissions or even acknowledge global warming? Nothing.
It’s time to stop pretending that there is a simple cure for the many and varied problems of our diverse Western forests. What’s needed is a cautious and site-specific approach to forest management. We also need a clear focus on actions that will protect human life and property.
There’s no question that wildfire is a serious threat to the many rural communities surrounded by logged-over forests. To deal with that threat, fuel reduction should be carried out in the immediate vicinity of those communities. Farther away, federal forest managers need to focus on thinning the regenerating plantations and small polewood stands that are the true forest tinderboxes.Together, Smokey Bear and public-lands loggers have created the conditions that global warming could turn into the perfect firestorm. But if we respond calmly and thoughtfully, we can do much to reduce the risk to our communities, without logging one big tree from our last remaining old forests.