Effects of Fire Intensity on Carbon Emissions from Various Soil Types. (S05-werts743911-poster)
Authors:
S.P. Werts* - Johns Hopkins University A.H. Jahren - Johns Hopkins University
Abstract:
The goal of this study is to document changes in the percent organic carbon and delta-13C values caused by exposure to temperatures seen in low-intensity to high-intensity fires. Soils were collected from sites in Delaware and Maryland, oven dried and exposed to elevated temperatures in a muffle furnace. Soils and soil horizons sampled spanned a range of soil type (Histosol, Inceptisol and Ultisol);
of percent organic carbon (0.11-26.6 %C); of % clay (0-22% clay); and were associated with widely different vegetation (hardwood forest to pine forest to salt marsh grass). Ten grams of soil from each horizon was incinerated in a muffle furnace at 50 degree increments from 150 to 900 degrees C for 6 hours to measure total carbon loss at each temperature. Preliminary results indicate that all soils studied lost at least half of their total organic carbon content after exposure to 300 degrees C for 6 h. After exposure to temperatures 600 degrees C or greater, all soils contained less than 0.006 % C. This suggests that the majority of soil organic carbon can be lost during low-intensity fires. Soil delta-13C values in the hardwood forest samples were observed to increase by as much as 5 ‰ after exposure to progressively increasing temperature, indicating that isotopically lighter components of soil organic matter are preferentially lost during burning. The application and comparison of these results to studies of soil in natural fire regimes will also be discussed.
Speaker Information: Scott Werts, Johns Hopkins University, 113 Olin Hall 3400 North Charles Street, Baltimore, MD 21218; Phone: 410-516-7521; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1626) Keywords: carbon; fire; emissions; organic
