Gaseous and Particulate Species Emissions from Different Forest Management Strategies Employing Prescribed Burning

KARSTEN BAUMANN (1), J. Mike Fort (1), Jamie J. Schauer (2), Don R. Blake (3), Ben E. Hartsell (4), Eric S. Edgerton (1)

(1) ARA Inc., Research Triangle Park, (2) University of Wisconsin, Madison, (3) University of California, Irvine, (4) ARA Inc., Plano

     Abstract Number: 786
     Last modified: May 14, 2010

Abstract
Prescribed burning (PB) is a mandated land management tool in the United States to recreate the natural habitat of endangered species in the South-Eastern pine forests. Annually, more than 8 million acres receive PB treatment with the majority occurring between January and May. In order to accelerate forest restoration efforts, primarily aimed at wildfire risk reduction, land managers employ mechanical thinning as additional fuel treatment option in fire-dependent ecosystems. In March 2010, we conducted a field experiment within the DoD-sponsored Defense Coastal/Estuarine Research Program, measuring in situ PB emissions from the combustion of pine dominated forest understory (incl. non-pine shrubs, litter and duff). Innovative mobile aerosol composition monitors were employed to measure and distinguish emissions from flaming versus smoldering stages, comparing emissions from untreated fuels (control) with mechanically thinned fuels (hydro-axed). All samples consisted of different components that have been analyzed for reactive gases, incl. NH3, HNO3, SO2, and light organic (carboxylic) acids, and particle-phase organic compounds (POC), water-soluble ionic species, organic and elemental carbon, and total PM2.5 mass. More than 100 POC species, including key molecular markers such as levoglucosan, pimaric acid, abietic acid, and retene were quantified and over 40 VOC species measured, incl. certain aromatics and biogenics (isoprene, mono-terpenes) that are important PM precursors. Numerous metallic and mineral elements determined via energy dispersive X-ray fluorescence and inductively coupled plasma mass spectrometry complete the emission profiles and factors. Sampling and analytical methods as well as preliminary results from this first field campaign are being presented. Potential benefits for source-receptor modeling and future land management procedures will be discussed.