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Hydrology and dissolved organic carbon biogeochemistry in an ombrotrophic bog
Author(s) -
Fraser C. J. D.,
Roulet N. T.,
Moore T. R.
Publication year - 2001
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.322
Subject(s) - dissolved organic carbon , peat , ombrotrophic , hydrology (agriculture) , bog , biogeochemistry , groundwater , meltwater , geology , snowmelt , environmental science , snow , geomorphology , oceanography , ecology , geotechnical engineering , biology
At the Mer Bleue bog, Ontario, Canada, DOC export measured at the basin outflow was −8·3 ± 3·7 g C m −2 yr −1 , and DOC loading via precipitation was estimated to be 1·5 ± 0·7 g C m −2 yr −1 . Discharge and DOC export calculated using a Dupuit–Forchheimer approximation compared well (within 1 g C m −2 yr −1 ) to outflow estimates of DOC export, and confirmed that outflow measurements were a suitable proxy for DOC seepage at the peatland margins. DOC export was 12% of the magnitude of the residual carbon sink measured at the peatland. The [DOC] across groundwater transects decreased with depth, and [DOC] sampled below 0·75 m depths remained fairly constant over the study period. However, [DOC] exported through the acrotelm (0 to 0·45 m peat depth) was variable, ranging from 40 mg l −1 after snowmelt to 70 mg l −1 during the growing season. Fluorescence analysis revealed that exported DOC was ‘allochthonous‐like’, whereas DOC in the catotelm (deeper layers of peat) became more ‘autochthonous‐like’ with depth. A conceptual model is developed to summarize the hydrological processes and controls which affect DOC biogeochemistry at the Mer Bleue. Copyright © 2001 John Wiley & Sons, Ltd.