Quantifying biogenic volatile organic compound (BVOC) emissions is critical in the development of effective ozone and fine particle control strategies in certain of California's airsheds. The ARB and the California academic community have promoted research in this area for more than two decades. Among our principal findings are that plant taxonomy provides a useful framework for categorizing emitting plant species, genera, and families, and that the volumetric method for estimating leaf masses for urban trees and oaks provides good agreement with field measurements, including whole-tree harvests. These taxonomic and volumetric methods facilitate use of species-specific databases to model natural and urban forest emission scenarios.
Many local governments in California have large-scale tree planting programs in cooperation with such groups as the Tree People. Increased tree cover reduces atmospheric carbon by sequestering carbon dioxide and by shading structures so that less fossil fuel is burned to power air conditioning. This reduces the overall pollution produced by the city, and contributes to the reduction of greenhouse gases in the atmosphere. There are also substantial energy cost-savings realized through the shading effect and by lowering urban temperatures (i.e. reducing urban heat islands). Additional canopy cover can also remove particulate matter and ozone by dry deposition on the leaves and by stomatal uptake. A case study of these beneficial phenomena while accounting for the biogenic emissions potential of certain tree species is the Los Angeles Department of Water and Power’s Cool Schools Program.
Arthur M. Winer – served for nearly a decade as Chair and Director of UCLA’s Environmental Science and Engineering Program in the School of Health. He was one of the first researchers to investigate the role of biogenic emissions in California’s atmospheres, and has published more than 150 peer-reviewed journal articles on this and other air pollution and atmospheric chemistry topics over the past three decades.