Stable Carbon Isotopic Fractionation in Smoke and Char Produced During Biomass Burning
Abstract
Stable isotopic ratio of carbon has been used extensively as a tracer of carbon sources in the environment. It has been documented that burning of C4 grasses resulted in significant depletion of C13 in the charcoal while burning of wood and C3 grass did not. This study was initiated to investigate the stable carbon isotopic fractionation of the smoke and char produced during biomass burnings. Samples of Juncus romerianus (C3 salt marsh grass) and Spartina alterniflora (C4 salt marsh grass), Eremochloa ophiuroides (centipede, a C4 lawn grass) and woody debris of a pine forest were colleted and burned in open air fire place. The particulate matter with diameters less than 2.5 micron (PM2.5) emitted from the burning was collected using a PM sampler. The original biomass, PM2.5, black C in PM2.5 and char (ash) were analyzed for their C, N and S thermograms using a multi-elemental scanning thermal analyzer and their stable C isotopic ratios were measured using an EA-IRMS. The results indicate that burning of wood and C3 grass did not produce significant C isotopic fractionation in PM2.5, black C in PM2.5 and char with respect to the original material. However, there was a significant C13-depletion in PM2.5 (-6.2 per mil), black C in PM2.5 (-4.6 per mil) and chars (-4.6 per mil) produced by burning of the C4 centipede grass; whereas the C4 Spartina salt marsh grass produced a C13-depletion in PM2.5 (-2.3 per mil) and black C in PM2.5 (-3.6 per mil), and a slight C13-enrichment in char (0.5 per mil). The isotope fractionation associated with burning of C4 vegetation is probably dependent on species and burning conditions and warrant further study.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFM.B54A..03W
- Keywords:
-
- 0414 Biogeochemical cycles;
- processes;
- and modeling (0412;
- 0793;
- 1615;
- 4805;
- 0428 Carbon cycling (4806);
- 0793 Biogeochemistry (0412;
- 0414;
- 1615;
- 4805;
- 4912);
- 3344 Paleoclimatology (0473;
- 4900);
- 4825 Geochemistry