Tomi P. Luoto (e-mail: email@example.com), Institute for Limnology, Austrian Academy of Sciences, Mondseestrasse 9, A-5310 Mondsee, Austria, and Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, FIN-00014 University of Helsinki, Finland; Kaarina Sarmaja-Korjonen (e-mail: firstname.lastname@example.org), Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, FIN-00014 University of Helsinki, Finland
Midge-inferred Holocene effective moisture fluctuations in a subarctic lake, northern Lapland
Article first published online: 12 MAY 2011
© 2011 The Authors. Boreas © 2011 The Boreas Collegium
Volume 40, Issue 4, pages 650–659, October 2011
How to Cite
LUOTO, T. P. and SARMAJA-KORJONEN, K. (2011), Midge-inferred Holocene effective moisture fluctuations in a subarctic lake, northern Lapland. Boreas, 40: 650–659. doi: 10.1111/j.1502-3885.2011.00217.x
- Issue published online: 27 SEP 2011
- Article first published online: 12 MAY 2011
- received 25th August 2010, accepted 5th April 2011.
Luoto, T. P. & Sarmaja-Korjonen, K. 2011: Midge-inferred Holocene effective moisture fluctuations in a subarctic lake, northern Lapland. Boreas, 10.1111/j.1502-3885.2011.00217.x. ISSN 0300-9483.
We examined fossil midge (Diptera: Chironomidae) assemblages from Lake Várddoaijávri, northern Finland to track Holocene effective moisture variability. Application of a midge-based water-depth calibration model showed that the early Holocene was characterized by a high water level compared with the Holocene average, but the inferred values decreased at c. 8000 cal. a BP and increased again towards c. 6000 cal. a BP. The inferred water level decreased at c. 5500 cal. a BP, but increased again towards c. 4000 cal. a BP. Between 4000 and 3000 cal. a BP the lake experienced two rapid events of lower water level. A relatively high water level detected at c. 3000 cal. a BP was followed by a lowering towards c. 2000 cal. a BP. The time period from c. 2000 cal. a BP onwards was characterized by a general rise in lake level towards the present. Overall, the present reconstruction shows a close correspondence in its trends to previous lake-level records in the region. Two common core taxa, Paratanytarsus and Corynocera ambigua, did not correlate significantly with water depth in the calibration data, creating a potential error source for the present lake-level reconstruction. However, statistical analysis showed a clear community response to long-term lake-level changes, and therefore the major trends in Holocene effective moisture patterns were revealed. The present palaeoclimatic information can also serve as valuable background data when assessing the effects of the present climate change.