Environmental Problems, Their Causes, and Sustainability 1

Figure 11-15 Surface fires (left) usually burn undergrowthand leaf litter on a forest floor and canhelp prevent more destructive crown fires (right)by removing flammable ground material. Sometimescarefully controlled surface fires are deliberatelyset to prevent buildup of flammable groundmaterial in forests.Surface fireCrown fireSometimes surface fires go underground and burnpartially decayed leaves or peat. Such ground fires aremost common in northern peat bogs. They may smolderfor days or weeks and are difficult to detect andextinguish.Solutions: How Can We Reduce ForestDamage from Fire? Set Little Fires, AllowSome Fires to Burn, and Clear VegetationNear BuildingsWe can reduce fire damage by setting controlledsurface fires to prevent buildup of flammablematerial, allowing fires on public lands toburn unless they threaten human structuresand lives, and clearing small areas aroundbuildings.Two ways to help protect forest resources from fire areprevention and prescribed burning (setting controlledground fires to prevent buildup of flammable material).Ways to prevent forest fires include requiringburning permits, closing all or parts of a forest to traveland camping during periods of drought and high firedanger, and educating the public about the ecologicaleffects of fire on forests.In the United States, the Smokey Bear educationalcampaign of the Forest Service and the National AdvertisingCouncil has prevented countless forest fires. Ithas also saved many lives and prevented billions of dollarsin losses of trees, wildlife, and human structures.However, this educational program convincedmuch of the public that all forest fires are bad andshould be prevented or put out. Ecologists warn thattrying to prevent all forest fires increases the likelihoodof destructive crown fires by allowing buildup ofhighly flammable underbrush and smaller trees insome forests.According to the U.S. Forest Service, severe firescould threaten about 40% of all federal forest lands,mainly through fuel buildup from past rigorous fireprotection programs (the Smokey Bear era), increasedlogging in the 1980s that left behind highly flammablelogging debris (called slash), and greater public use offederal forest lands. In addition, an estimated 40 millionpeople now live in remote forested areas or areaswith highly flammable chaparral vegetation with ahigh wildfire risk.Ecologists and forest fire experts propose severalstrategies for reducing the harm from fires to forestsand people. One is to set small prescribed surface firesor clear out (thin) flammable small trees and underbrushin the highest-risk forest areas. But prescribedfires require careful planning and monitoring to keepthem from getting out of control.During the spring of 2000, for example, a poorlyplanned prescribed fire got out of hand in an areamanaged by the Park Service near Los Alamos, NewMexico. The result was a 33-day fire that burned 19,000hectares (47,000 acres), destroyed or damaged 280homes, damaged 40 structures at the Los AlamosNational Laboratory, and caused an estimated $1 billionin damages. In parts of fire-prone California, localofficials are using goats as an alternative to prescribedburns (Solutions, right).Another strategy is to allow many fires in nationalparks, national forests, and wilderness areas to burnand remove flammable underbrush and smaller treesas long as the fires do not threaten human structuresand life. A third approach is to protect houses or otherbuildings by thinning a zone of 46–61 meters (150–200feet) around such buildings and eliminating flammablematerials such as wooden roofs.In 2003, the U.S. Congress passed a law called theHealthy Forests Initiative. Under this law, timber companiesare allowed to cut down economically valuablemedium and large trees in most national forestsfor 10 years in return for clearing away smaller, morefire-prone trees and underbrush. The law also exemptsmost thinning projects from environmentalreviews and appeals currently required by forest protectionlaws.Will the law achieve the stated goal of reducingwildfires? According to biologists and many forest firescientists, this law is likely to increase the chances of se-208 CHAPTER 11 Sustaining Terrestrial Biodiversity: Managing and Protecting Ecosystems