Patterns and regulation of dissolved organic carbon: An analysis of 7,500 widely distributed lakes

Limnology and Oceanography - Tập 52 Số 3 - Trang 1208-1219 - 2007
Sebastian Sobek1, Lars J. Tranvik1, Yves T. Prairie2, Pirkko Kortelainen3, Jonathan J. Cole4
1Limnology / Department of Ecology and Evolution, Uppsala University, Box 573, 75123 Uppsala, Sweden
2Limnology Département des Sciences Biologiques, Université de Québec à Montréal, Case Postale 8888, succ. Centre-ville, Montréal, Québec H3C 3P8, Canada
3Finnish Environment Institute, P.O. Box 140, 00251 Helsinki, Finland
4Institute of Ecosystem Studies, Box AB, Milbrook, New York 12545

Tóm tắt

Dissolved organic carbon (DOC) is a key parameter in lakes that can affect numerous features, including microbial metabolism, light climate, acidity, and primary production. In an attempt to understand the factors that regulate DOC in lakes, we assembled a large database (7,514 lakes from 6 continents) of DOC concentrations and other parameters that characterize the conditions in the lakes, the catchment, the soil, and the climate. DOC concentrations were in the range 0.1–332 mg L−1, and the median was 5.71 mg L−1. A partial least squares regression explained 48% of the variability in lake DOC and showed that altitude, mean annual runoff, and precipitation were negatively correlated with lake DOC, while conductivity, soil carbon density, and soil C:N ratio were positively related with lake DOC. A multiple linear regression using altitude, mean annual runoff, and soil carbon density as predictors explained 40% of the variability in lake DOC. While lake area and drainage ratio (catchment : lake area) were not correlated to lake DOC in the global data set, these two factors explained significant variation of the residuals of the multiple linear regression model in several regional subsets of data. These results suggest a hierarchical regulation of DOC in lakes, where climatic and topographic characteristics set the possible range of DOC concentrations of a certain region, and catchment and lake properties then regulate the DOC concentration in each individual lake.

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Limnology and Oceanography

Tập 52 Số 3

1208-1219

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