A prescription for controlling the air pollution resulting from the use ofprescribed biomass fire: clouds

Forestry, conservation, wildfire risk reduction, and agricultural uses of p lanned or prescribed fires as a tool for meeting the needs of wildland mana gers are increasingly in collision at the air pollution control and climate change cross-roads. The inevitable conflict resulting from the disparate g oals of users has long been the subject of a combination of both systems an d ecologically integrated analysis attempting to minimize the environmental impact and maximize the economic and societal benefits of this land manage ment technique. We offer here experimental evidence for the viability of im plementing a pollution control option that could substantially reduce the p articulate emissions from prescribed fires in biomass and explore some of t he logical implications of these concepts. In nature, clouds and precipitation are the principal mechanisms by which t he atmosphere is cleansed of particulate pollution, aerosols and smokes. We propose here, for consideration, using clouds as a part of the prescriptio n for scheduling biomass fires. Since in most areas biomass fire is already carried out within a detailed p rescriptive plan which includes meteorological forecasts, the addition of a dditional meteorological scheduling constraints should be acceptable to mos t users providing that the benefits are correspondingly large. Reducing par ticulate smoke emissions in all size classes by at least 50% seems practica ble.