HR: 0830h
AN: B31C-0315    [PDF]
TI: Formation of Colloidal and Particulate Organic Carbon in Boreal Streams and Lakes
AU: * Kelton, N
EM: nkelton@yorku.ca
AF: York University, 4700 Keele Street, Toronto, ON M3J 1P3 Canada
AU: Molot, L A
EM: lmolot@yorku.ca
AF: York University, 4700 Keele Street, Toronto, ON M3J 1P3 Canada
AB: The boreal lakes of Ontario store large amounts of carbon in their sediments, second only to peatlands in magnitude. This carbon is exported to these oligotrophic lakes primarily as dissolved organic carbon (DOC) from adjacent peatlands by streams, however, the mechanisms by which the sediments accumulate this carbon as particulate organic carbon (POC) are not understood. It is important that we comprehend these processes in order to understand how disturbance could affect this storage. Floc formation has been observed in irradiated boreal stream and lake waters. Samples irradiated under low UV intensities produced more floccular material compared to samples irradiated under high UV intensities, while little material was observed in dark controls. TEM work has indicated that microbial extracellular reactions may initiate this floc formation, hence, both bacteria and UV radiation may play a role in POC formation. Data from fractionated chemical analyses and TEM imaging will be presented.
DE: 0400 Biogeosciences
DE: 1615 Biogeochemical processes (4805)
DE: 1845 Limnology
SC: Biogeosciences [B]
MN: 2003 Fall Meeting