Scientific American November 2002 [antikvár]

SA Perspectives Land of Fire As you read this, the horrific 2002 wildfire season is drawing to a close. And in what has become an annual ritual, many are asking, "Why are things so bad?" This summer more than six million acres burned, thousands of people had to flee for their lives, and the cost of battling those blazes could hit $1.5 billion. Smokey Bear may have done too good a job. Decades of well-intentioned fire suppression, combined with recent droughts, have left vast tracts of wildland littered with tinder-dry brush and matchsticklike trees. Of 470 million acres of federally managed forests, 190 million or so are said to be at risk of catastrophic fire. Various efforts are now under way to remove excessive brush, and a growing number of people are endorsing the idea of thinning Western forests. Igniting a new debate, President George W. Bush recently announced a plan to remove forest-floor fuels for "free," by letting loggers cut larger, more commercially valuable trees in exchange. Many argue about the appropriate levels of thinning, how it might be accomplished and even whether it's a good idea at all. But at least everyone agrees that research will improve the prevention and management of conflagrations [see "Burning Questions," by Douglas Gantenbein, on page 66], All the efforts to handle forest fires must proceed from a simple realization: fire is a fact of life in Western ecosystems, in more ways than one. Western forests are supremely adapted to coexist with natural, lightning-sparked burns. Before they were quashed by Smokey, these fires had cyclically swept up brush and debris every few years. The thick bark of native Ponderosa pines, for example, insulated the trees from damage. In fact, some varieties of pinecones won't release seeds without exposure to fire's heat. So the efforts to hack away underbrush and to phase out routine fire suppression are welcome. But they are also incomplete. The root cause of the problem is not an overly zealous desire to save trees but frenetic development. The conifer-covered slopes of the West are magnetic for homesteaders. Builders slip more and more houses among the picturesque trees, creating what fire managers call the urban-wildland interface. According to the National Interagency Fire Center in Boise, Idaho, fire-susceptible areas hold 10 times as many homes today as 25 years ago. Although houses can be built using noncombustive materials and modified with other fire-smart praaices, they nonetheless create a need for fire suppression that never used to exist. In certain areas, the situation has become untenable: natural fires cannot be left to run their course, the underbrush builds up, and eventually the forest explodes in an uncontrollable blaze. It is hardly the first time that humans, in our desire to be close to natiure, have destroyed the very thing we seek. Fortunately, new policies can reduce the cost in lives, property and environmental conditions. As state and local plaimers consider what and how to build, they must recognize the inevitability of fire in the same way that other regions prepare for floods, earthquakes or hurricanes. Communities such as Malibu, Calif., already have strict building codes in place. Insurance companies can require more discrimination from their clients in site choices. Stronger steps, including bans on building in fire-prone areas, may eventually prove necessary. Some people might regard preventive measures as overbearing government interference. But unless we start making these hard trade-offs, we may find ourselves continuing to fiddle while the West burns. THE [email protected]