A first chironomid-based summer temperature reconstruction (13-5 ka BP) around 49 degrees N in inland Europe compared with local lake development

• Published in: Quaternary Science Reviews
• Main Authors: Hajkova, Petra, Paril, Petr, Petr, Libor, Chattova, Barbora, Grygar, Tomas Matys, Heiri, Oliver
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: PERGAMON-ELSEVIER SCIENCE LTD 2016
• Subjects: Greenland; Greenland ice cores
• Online Access: https://edoc.unibas.ch/67698/; https://doi.org/10.1016/j.quascirev.2016.04.001

Temperature reconstructions for the end of the Pleistocene and the first half of the Holocene based on biotic proxies are rare for inland Europe around 49 degrees N. We analysed a 7 m long sequence of lake deposits in the Vihorlat Mts in eastern Slovakia (820 m a.s.l.). Chironomid head capsules were used to reconstruct mean July temperature (T-July), other proxies (diatoms, green algae, pollen, geochemistry) were used to reconstruct local environmental changes that might have affected the climate reconstruction, such as epilimnetic total phosphorus concentrations (TP), lake level changes and development of surrounding vegetation. During the Younger Dryas (YD), temperature fluctuated between 7 and 11 degrees C, with distinct, decadal to centennial scale variations, that agree with other palaeoclimate records in Europe such as delta O-18 content in stalagmites or Greenland ice cores. The results indicate that the site was somewhat colder than expected from the general south-to-north YD temperature gradient within Europe, possibly because of north-facing exposition. The warmer phases of the YD were characterised by low water level or even complete desiccation of the lake (12,200-12,400 cal yr BP). At the Late-Glacial/Holocene transition T-July steeply increased from from 11 to 15.5 degrees C (11,700-11,400 cal yr BP) - the highest T-July for entire sequence. This rapid climate change was reflected by all proxies as a compositional change and increasing species diversity. The open woodlands of Pinus, Betula, Larix and Picea were replaced by broad-leaved temperate forests dominated by Betula, later by Litmus and finally by Corylus (ca 9700 cal yr BP). At the same time, input of eroded coarse-grained material into the lake decreased and organic matter (LOI) and biogenic silica increased. The Early-Holocene climate was rather stable till 8700 cal yr BP, with temporary decrease in T-July around 11,200 cal yr BP. The lake was productive with a well-developed littoral, as indicated by both diatoms and chironomids. A ...