Buffam, Ishi
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
- University of Wisconsin-Madison
Research article2008Peer reviewedOpen access
Agren, Anneli; Buffam, Ishi; Berggren, Martin; Bishop, Kevin; Jansson, Mats; Laudon, Hjalmar
The character and quantity of dissolved organic carbon (DOC) were studied in nine small boreal streams and adjacent soils during two years, with focus on the spring snowmelt period. The streams cover a forest-wetland gradient, spanning from 0% to 69% wetland coverage. Lower values of the absorbance ratio measured at 254 nm and 365 nm (A(254)/A(365)), in both soil plots and streams, indicated that wetland-derived DOC had higher average molecular weight than forest DOC. Higher SUVA(254) ( DOC specific ultraviolet absorption at 254 nm) in wetland runoff indicated more aromatic DOC from wetlands than forests. During low flow, the stream DOC character was sensitive to the forest-wetland proportion of the catchment, and when wetland coverage exceeded 10%, the streams appeared to be dominated by wetland-derived DOC. During the spring snowmelt period, the character changed to lower molecular weight and more aliphatic DOC, particularly in streams with a high proportion of forest in the catchment. The forested soil solutions had higher A(254)/A(365) in the surface horizons that were hydrologically activated during the high flow events, while wetland soil solution had relatively low A(254)/A(365) at all depths. Consequently forest soils contributed more to stream DOC concentration during snowmelt that during winter low flow.
Journal of Geophysical Research
2008, Volume: 113, number: G3, article number: G03031
Publisher: AMER GEOPHYSICAL UNION
Environmental Sciences related to Agriculture and Land-use
DOI: https://doi.org/10.1029/2007JG000674
https://res.slu.se/id/publ/19425