Threats and Strategies for Global Biodiversity Conservation

Box 5. Needs for Integrated Fire Management in MexicoEvaluating whether the effects offire will be detrimental, beneficialor benign.In Mexico, fire-dependent ecosystemsinclude pine forests, oak forests,grasslands, shrublands and palmettolands, among others. Examples offire-sensitive ecosystems includepine forests, rain forests, cloudforests, mangrove forests, fir forestsand shrublands. However, as in manyother parts of the world, relativelylittle scientific information is availableto evaluate whether the effectsof fire will be detrimental, beneficialor a mixture of both.Evaluating whether the effects of firewill be detrimental, beneficial orbenign is of particular significancein Mexico. In 2000, the Universityof Chapingo—in partnership withthe National Council for Scienceand Technology (CONACYT),the National Forest Commission(CONAFOR), the Mexico Citygovernment and the communities ofSan Miguel and Santo Tomás Ajusco—began the Ajusco research projectto study fire ecology and IntegratedFire Management in the pinelandsof Central Mexico and other ecosystems,as well as establish demonstrationplots. The project sought tosupplement the small amount ofexisting fire research in Mexico.Conservation of the forest at theAjusco volcano (in central Mexiconear Mexico City) is critical becauseof its fire-dependent, high altitudePinus hartwegii forests (reaching 4,300meters at the Iztaccihuatl volcano)and the potential impacts of climatechange. In fact, the condition of Pinushartwegii forests can be an indicatorof global warming.Weighing the relative benefits andrisks of fire and human actions.The Ajusco research project inCentral Mexico is representative offire- and society-related problemscommon to the whole country,as well as those common to areasinfluenced by urban development.This area has one of the highestnumbers of fires in Mexico, most ofthem human-caused. The area is alsorepresentative of the environmentalservices that such forests provideto cities, such as clean water. Thisproject is based on sound sciencegenerated in-situ and can be used todemonstrate biodiversity conservationwithin the context of commonsocio-economic issues.Results from a considerable numberof graduate and post-graduateresearch projects in the area showthat low intensity prescribed burnsin pine forests approximately doublethe number of understory species(Martínez-Hernández andRodríguez-Trejo 2003), with thesebeneficial effects lasting three yearsfollowing burning. Some understoryspecies on burned sites also helped“nurse” planted trees toward successfulestablishment by increasingnutrient availability (phosphorousand potassium). Virtually all juveniletrees survived the low intensity prescribedburns in March, whereashardly any survived the high intensityprescribed burns in May (Rodríguez-Trejo et al. 2007). Low crownscorch associated with low intensityprescribed burns promoted treegrowth (González-Rosales andRodríguez-Trejo 2004, Vera-Vilchisand Rodríguez-Trejo 2007) and hadthe additional benefit of increasingthe recreational value of the landscape(Romo-Lozano et al. 2007).Continuing fire research in Mexicowill add substantially to the country’sability to understand the ecologicalroles of fire. However, the effectiveimplementation of IFM alsodepends on the relative benefits andrisks of fire, and the capacity torespond appropriately and effectivelybased on landscape objectives.The University of Chapingo andCONAFOR recently analyzedthe Mexican federal fire programfor the 2003 and 2004 fire seasons.In 2003, 8,211 forest fires covering322,448 hectares were recorded.Half of these fires were caused byagricultural and cattle ranchingactivities, smokers and camp fires.The evaluation of emissions of sevenpollutants from these fires reached6.2 million Mg, a large percentageof which was released as CO2.The losses in wood, firewood, andreforestation costs reached US$380million, which does not account forlosses in other forest resources,recreation or human health.16