Arctic Lake Response to Warming: A Paleolimnological Investigation in the Northwest Territories, Canada

The overall objective is to determine how responsive lake primary production at the northern treeline is to warming today in comparison to the Holocene Thermal Maximum (HTM) to increase our knowledge of Arctic lake ecosystem sensitivity to climate change. Paleolimnological techniques, including chlo...

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Bibliographic Details
Main Author: Brasier, Brittany
Format: Text
Language:English
Published: Scholarship@Western 2023
Subjects:
Paleolimnology
Arctic lakes
diatoms
climate change
Canada
chlorophyll
Terrestrial and Aquatic Ecology
Arctic
Arctic Lake
Northwest Territories
Yellowknife
Climate change
Tundra
Online Access:https://ir.lib.uwo.ca/etd/9106
https://ir.lib.uwo.ca/context/etd/article/11888/viewcontent/auto_convert.pdf
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Summary:The overall objective is to determine how responsive lake primary production at the northern treeline is to warming today in comparison to the Holocene Thermal Maximum (HTM) to increase our knowledge of Arctic lake ecosystem sensitivity to climate change. Paleolimnological techniques, including chlorophyll a and biogenic silica to infer overall lake and diatom production, respectively, were measured in 10,000-year sediment records from two tundra lakes, Queen’s and McMaster Lakes, located near Yellowknife, Northwest Territories. Diatoms were enumerated to identify lake ecosystem response to warming. Lake primary production increased at both lakes during the HTM beginning about ~8,400 cal yr BP due to warming temperatures. Recent anthropogenic warming is more rapid than during the HTM and recent increases in lake primary production are unprecedented. Changes in diatom community composition indicate that increased temperatures during both warming periods led to decreased ice-cover duration and increased growing season serving as drivers for increased lake production.

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