CGRG Bibliography of Canadian Geomorphology
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Author : Dixit, S.S.; Keller, W.; Dixit, A.S.; and Smol, J.P.
Date : 2000.
Title : Diatom-inferred dissolved organic carbon reconstructions provide assessments of past UV-B penetration in Canadian Shield Lakes
Publication : 8th International Paleolimnology Symposium, August 20 to August 24, 2000. Queen's University, Kingston, Ontario
Issue :
Page(s) :
Abstract
Paleolimnological approaches have provided strong inference models for lakewater acidity and metal concentrations in Sudbury area lakes, but calibration data have not yet been explored for inferring lakewater dissolved organic carbon (DOC). A review of available limnological data provided DOC values for 80 of our 105 surface sediment calibration lakes. This has allowed us to examine the relative importance of DOC in determining the distribution of diatom assemblages in Canadian shield lakes, such as in the Sudbury region. Canonical correspondence analysis indicated that lakewater DOC accounted for a statistically significant proportion of additional variation in the diatom species data. A DOC inference model was developed, using weighted averaging calibration and regression approaches. The relationship between measured and diatom-inferred DOC was strong (r2=0.64). Using this model we reconstructed historical DOC concentrations in three Sudbury area lakes, and then estimated temporal changes in UV-B penetration using the inferred DOC data. The close correspondence between inferred and measured DOC values for the 1980s in all three lakes provides further evidence that the diatom assemblages are accurately inferring lakewater DOC concentrations. Past DOC concentrations in Sudbury lakes offer an excellent technique to assess both individual and interactive effects
Bibliography of Canadian Geomorphology