Fire Environment Effects on Particulate Matter Emission Factors in Southeastern U.S. Pine-Grasslands
Kevin Robertson
Recording of a webinar presentation to the National Wildfire Coordinating Group Smoke Committee (SmoC), April 2016
See also the pdf file of the slides from this presentation
Abstract: Particulate matter (PM) emission factors (EFPM), which predict PM emissions per biomass consumed, have a strong influence on PM emission inventories. PM < 2.5 mm diameter (PM2.5) is of special concern for human health. EFPM2.5 is typically held constant for the region or general fuel type being assessed. This study used structural equation modeling (SEM) to measure effects of fire environment variables on EFPM2.5 in U.S. pine-grasslands to refine their application in emission inventories. An a priori model was tested using 41 prescribed burns in Florida and Georgia, USA with varying years since previous fire, season of burn, and fire direction of spread. The SEM showed EFPM2.5 to be higher in burns conducted at higher ambient temperatures, corresponding to later dates from winter to summer and increases in live herbaceous vegetation and ambient humidity, but not total fine fuel moisture content. Pine needles had the strongest positive effect on EFPM2.5, and grass had a negative effect on EFPM2.5. Results of the study suggest that timber thinning and frequent prescribed fire minimize EFPM2.5 and total PM2.5 emissions on a per burn basis. Further development of PM emission models should consider adjusting EFPM2.5 as a function of these common land use variables.
Kevin Robertson received his BS in Botany from Louisiana State University and Ph.D. in Plant Biology at the University of Illinois. He is currently the Fire Ecology Program Director at Tall Timbers Research Station and Land Conservancy. There he studies the plant community ecology of southeastern U.S. pine ecosystems, the natural history of the Gulf Coastal Plain, remote sensing of fire, effects of fire regime on plant communities, soils, and fire behavior, and prescribed fire effects on air quality. He also provides extension and education regarding the use of prescribed burning in fire-dependent ecosystems of the southeastern U.S.
