Chrysophyte microfossils record marked responses to recent environmental changes in high- and mid-arctic lakes

Rapid stratigraphic changes are recorded in recent assemblages of subfossil Chrysophyceae from the sediments of two highly contrasted arctic lakes, one situated in the polar desert of west-central Ellesmere Island, and the other on eastern Baffin Island in the mid-Arctic climatic zone. In Sawtooth L...

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Bibliographic Details
Published in:Canadian Journal of Botany
Main Authors: Wolfe, Alexander P, Perren, Bianca B
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2001
Subjects:
Plant Science
Arctic
Baffin Island
Ellesmere Island
Canadian Arctic Archipelago
Arctic Lake
Cumberland Peninsula
Fosheim Peninsula
Arctic Archipelago
Baffin
polar desert
Online Access:http://dx.doi.org/10.1139/b01-044
http://www.nrcresearchpress.com/doi/pdf/10.1139/b01-044
Description
Summary:Rapid stratigraphic changes are recorded in recent assemblages of subfossil Chrysophyceae from the sediments of two highly contrasted arctic lakes, one situated in the polar desert of west-central Ellesmere Island, and the other on eastern Baffin Island in the mid-Arctic climatic zone. In Sawtooth Lake on the Fosheim Peninsula, concentrations of chrysophycean stomatocysts increase dramatically in sediments deposited since AD 1920. Only trace abundances of stomatocysts are encountered in older sediments. In Kekerturnak Lake, on the north coast of Cumberland Peninsula, scales of Mallomonas spp., previously absent from the sediment record, appear suddenly in the upper 5.5 cm of sediment and subsequently become ubiquitous in the top 1.0 cm. These results corroborate diatom stratigraphic data from other sites in the Canadian Arctic Archipelago, together suggesting that unprecedented ecological changes are presently occurring across this vast region. In all likelihood, these abrupt algal community shifts reflect the response of arctic lake ecosystems to well-documented climate warming since the Little Ice Age, with the implications that recent rates of environmental change are unprecedented in the context of the Holocene.Key words: Paleolimnology, arctic lakes, Chrysophyceae, stomatocysts, Mallomonas.

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