Freshwater diatom biogeography in the Canadian Arctic Archipelago

Authors

  • Giselle Bouchard,

    Corresponding author
    1. Laboratory for Paleoclimatology and Climatology, Department of Geography and Ottawa-Carleton Geoscience Centre, University of Ottawa, Ottawa, Ontario
      *Giselle Bouchard, Laboratory for Paleoclimatology and Climatology, Department of Geography, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada. E-mail: bouchard@magma.ca
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  • K. Gajewski,

    1. Laboratory for Paleoclimatology and Climatology, Department of Geography and Ottawa-Carleton Geoscience Centre, University of Ottawa, Ottawa, Ontario
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  • P. B. Hamilton

    1. Research Division, Canadian Museum of Nature, Ottawa, Ontario, Canada
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*Giselle Bouchard, Laboratory for Paleoclimatology and Climatology, Department of Geography, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada. E-mail: bouchard@magma.ca

Abstract

Aim  Document the biogeographical distributions of diatoms in the Canadian Arctic in relation to environmental factors.

Location  The Canadian Arctic Archipelago.

Methods  Diatoms were extracted from lake sediments and treated using standard methods. Rarefaction-estimated species richness, diatom concentrations (valves cc−1), and diatom abundance were mapped using a Geographic Information System. The physical and chemical parameters of the lakes were measured.

Results  A total of 326 taxa from 63 genera were found in 62 lakes of the study area. Up to 85 and as low as eight taxa were identified in any one lake, and rarefaction-estimated species richness correlated with lake size. Nearby lakes could have greatly different diatom assemblages. Many taxa showed limited distributions. Response surfaces and ordination techniques indicate that a large number of taxa prefer colder regions of the Arctic while the abundance of others was influenced by lake water chemical parameters such as TKN and SiO2.

Main conclusions  Although many taxa were common and found across the study area, diatom assemblages showed regional differences in the Arctic. Some taxa were not found in either the northern or southern parts of the Archipelago and others were restricted to particular regions. Newly delineated genera showed interpretable geographical patterns and could be related to environmental factors, suggesting that this more natural grouping may enhance our understanding of diatom ecology. Geographical, physical, and chemical factors are needed to explain diatom distributions in the Arctic.

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