HIGH RESOLUTION MASS SPECTROMETRIC ANALYSIS OF DOM FROM A FIRE-IMPACTED WATERSHED:EVIDENCE FOR EXPORT OF TERRESTRIAL BLACK CARBON TO AQUATIC ECOSYSTEMS

摘要

Recent reviews point out that over half of the organic carbon in Earth's terrestrial and marine environments remains uncharacterized at the molecular level(l-tedges et al.,2000).Meanwhile,investigations of fire-impacted regions suggest that as much as 45% of organic carbon in soils(Schmidt et al.,1999)and 15-50% in sediments(Masiello and Druffel,1998)may be attributed to black carbon(BC);accounting for a substantial portion of uncharacterized organics.The current understanding of production and turnover implies that BC is both a long-term carbon sink,and a ubiquitous organic constituent of soil and sediment whose ecological functions are largely unknown.