Subfossil chironomid stratigraphy of a small acid lake in southern Finland

Chironomid analysis was used to study ecological changes in shallow oligotrophic Lake Orajärvi in Espoo, southern Finland. A 53 cm long sediment core for chironomid analysis was obtained at 6 m depth. Changes in chironomid composition of the Lake Orajärvi are related to temperature changes and anthr...

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Bibliographic Details
Main Author: H. Olander
Format: Article
Language:English
Published: Geological Society of Finland 1992-12-01
Series:Bulletin of the Geological Society of Finland
Subjects:
Online Access:http://www.geologinenseura.fi/bulletin/Volume64/sgs_bt_064_2_pages_183_188.pdf
Description
Summary:Chironomid analysis was used to study ecological changes in shallow oligotrophic Lake Orajärvi in Espoo, southern Finland. A 53 cm long sediment core for chironomid analysis was obtained at 6 m depth. Changes in chironomid composition of the Lake Orajärvi are related to temperature changes and anthropogenic acidification. Decline of Microtendipes and emergence of Heterotrissocladius at 30–35 cm depth are due to deteriorating climate after Holocene climatic optimum. Most recent changes in chironomid fauna can be related to strong human induced acidification of the lake, which has led to domination of Dicrotendipes and Psectrocladius. Chironomid analysis, which mostly has been used in deep stratified lakes, seems to be a valid method also in shallow unstratified lakes.
ISSN:0367-5211
1799-4632