Paleolimnology of Two Shallow Lakes in Central Alberta, Canada
作者:
J. R. Forbes,
M. Hickman,
期刊:
Internationale Revue der gesamten Hydrobiologie und Hydrographie
(WILEY Available online 1981)
卷期:
Volume 66,
issue 6
页码: 863-888
ISSN:0020-9309
年代: 1981
DOI:10.1002/iroh.19810660610
出版商: Akademie Verlag, Berlin
关键词: paleolimnology;water quality;productivity;pigments;organic matter
数据来源: WILEY
摘要:
AbstractAn interpretation of postglacial change in water quality and productivity has been made for two shallow lakes in Central Alberta, Canada, namely Hastings Lake (longitude 113° 00′ W; latitude 53° 30′ N) and Lac Ste. Anne (longitude 114° 21′ W; latitude 53° 41′ N). Erosion rates around Lac Ste. Anne have remained constant. Similarly productivity has changed little although macrophytes contributed more to total production during the early stages. Hastings Lake has responded more sensitively to changes in the balance of precipitation and evaporation. From 5500 to 4000 year B. P. it was shallower than at present. Productivity during this early phase was less but macrophytes and allochthonous organic matter (i. e., leaf litter) probably contributed a greater proportion of the organic influx. After water levels rose productivity increased remaining steady until 2500 year B. P. when a slight decline occurred. Throughout the high water period oxygen depletion has not been serious. Any period of reducing conditions has been brief. Productivity has never been nutrient‐limited. Elevation of the lake surface increased potential volume for production and reduced turbulent resuspension of bottom sediments permitting greater light penetration, and enhanced algal production. Difference between the sedimentary record of these two lakes, as well as the two basins of Hastings Lake, demonstrates the individualistic responses of basins and lakes to cl
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