Sources, sinks, and fluxes of dissolved organic carbon in subarctic fen catchments

• Main Author: Koprivnjak, Jean-François
• Format: Thesis
• Language: English
• Published: McGill University 1991
• Subjects: Fens > Québec (Province); Carbon cycle (Biogeochemistry); Soils > Carbon content > Québec (Province); Subarctic
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60045

The sources, sinks, fluxes, spatial distributions, and temporal variations of dissolved organic carbon (DOC) in subarctic fen catchments as well as the temporal patterns of DOC in streams draining subarctic fen catchments in the region of Schefferville, Quebec were investigated. In June to August sampling, DOC concentrations averaged 17 mg/L in peat water, 2-16 m/L in stream water, 49-56 mg/L in canopy throughfall, 14-19 mg/L in understory throughfall, 122-187 mg/L in stemflow, 25-39 mg/L in lichen and moss mat water, and 35-42 mg/L in soil A horizon water. Precipitation and canopy and understory throughfall were all significant DOC sources with seasonal DOC fluxes to the forest floor of 0.1-0.4, 0.5-1.3, and 0.8-1.7 g DOC/m$ sp2$ of forest, respectively. The lichen and moss mats and the A soil horizon were also found to be DOC sources, whereas the B soil horizon was a DOC sink. The soil column was estimated to export 0.4-0.5 g DOC/m$ sp2$. Peat, also a DOC source, released 1.2-2.1 g DOC/m$ sp2$. DOC concentrations in streams draining ten fen catchments were found to be positively correlated with the percentage of fen area in the catchments.