Paleohydrology inferred from diatoms in northern latitude regions |
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| Authors: | KA Moser A Korhola J Wekcström T Blom R Pienitz JP Smol MSV Douglas MB Hay |
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| Institution: | (1) Department of Geography, University of Utah, 260 S Central Campus Dr. Rm 270, Salt Lake City, Utah 84112-9155, USA;(2) Laboratory of Physical Geography, Department of Geography, University of Helsinki, P.O. Box 9, Siltavuorenpenger 20 A, FIN-00014, Finland;(3) Départment de géographie and Centre d'études nordiques, Université Laval, Sainte-Foy, Québec, G1K 7P4, Canada;(4) PEARL, Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada;(5) Department of Geology, University of Toronto, 22 Russell Road, Toronto, Ontario, M5S 3B1, Canada |
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| Abstract: | Several recent studies have successfully applied diatom-based paleolimnological techniques to infer past hydrological changes in arctic and subarctic regions. For example, we summarize arctic studies that attempt to determine changes in peat water content, flood frequency, river discharge, effective moisture and ice cover in northern regions. Some of the investigations are still in preliminary stages, but represent innovative approaches to study arctic and subarctic paleohydrology. New data demonstrate that lake depth, which may be related to changing hydrological conditions, is a significant variable influencing the distributions of diatom taxa in lake surface sediment calibration sets from Wood Buffalo National Park (WBNP), on the border of Alberta and the Northwest Territories, Canada, and from Fennoscandia (mainly northwest Finland). Weighted averaging regression and calibration methods were used to develop quantitative inference models for lake depth using diatom assemblages preserved in surface sediments. The predictive abilities of the transfer functions were relatively high (for WBNP r2 = 0.70 and RMSE = 2.6 m, and for Fennoscandia r2 = 0.88 and RMSE = 1.8 m). However, evaluating the transfer functions using jack-knifing procedures indicated lower predictive abilities, possibly reflecting the relatively small sample size and/or short gradients used in these calibration sets. Such transfer functions can be used to track overall trends in lake levels, and provide an objective assessment as to directions of changing lake levels. Any interpretations of inferred lake levels, especially those related to climate change, must be made cautiously and must include some understanding of the local, present-day hydrological system. |
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| Keywords: | paleohydrology lake level lake depth diatoms subarctic arctic hydrology lakes |
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