Indonesia has the second largest expanse of tropical forest and the highest number of endemic species in the world, so fires there are of special concern. The dry season in tropical Southeast Asia has probably always been a time of burning vegetation and smoky skies. Tinder-dry forests are ignited by lightning or fires set by farmers to clear cropland. Generally burning only a hectare or two at a time, traditional shifting cultivators often help preserve plant and animal species by opening up space for early