Dissolved Black Carbon in Grassland Streams: Is There an Effect of Recent Fire History?

Authors

Yan Ding, Southeast Environmental Research Center, Department of Chemistry & Biochemistry, Florida International UniversityFollow
Youhei Yamashita, Faculty of Environmental Earth Science, Hokkaido UniversityFollow
Walter K. Dodds, Division of Biology, Kansas State University
Rudolf Jaffe´, Southeast Environmental Research Center, Department of Chemistry and Biochemistry, Florida International University,Follow

Abstract

While the existence of black carbon as part of dissolved organic matter (DOM) has been confirmed, quantitative determinations of dissolved black carbon (DBC) in freshwater ecosystem and information on factors controlling its concentration are scarce. In this study, stream surface water samples from a series of watersheds subject to different burn frequencies in Konza Prairie (Kansas, USA) were collected in order to determine if recent fire history has a noticeable effect on DBC concentration. The DBC levels detected ranged from 0.04 to 0.11 mg L⁻¹, accounting for ca. 3.32 ± 0.51% of dissolved organic carbon (DOC). No correlation was found between DBC concentration and neither fire frequency nor time since last burn. We suggest that limited DBC flux is related to high burning efficiency, possibly greater export during periods of high discharge and/or the continuous export of DBC over long time scales. A linear correlation between DOC and DBC concentrations was observed, suggesting the export mechanisms determining DOC and DBC concentrations are likely coupled. The potential influence of fire history was less than the influence of other factors controlling the DOC and DBC dynamics in this ecosystem. Assuming similar conditions and processes apply in grasslands elsewhere, extrapolation to a global scale would suggest a global grasslands flux of DBC on the order of 0.14 Mt carbon year⁻¹.

Comments

The definitive publisher-authenticated version is available online at http://dx.doi.org/10.1016/j.chemosphere.2012.10.098

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Ding, Y., Y. Yamashita, W. Dodds, R. Jaffe. 2013. Dissolved black carbon in grassland streams: Is there an effect of recent fire history? Chemosphere 90: 2557-2562. DOI: 10.1016/j.chemosphere.2012.10.098