Preliminary results on development of a chironomid-based mean july air temperature inference model for the Turkish Lakes

Abstract

As a preliminary study, surface sediment recovered from 30 lakes in Turkey was analysed for subfossil chironomid (Insecta: Diptera) remains and incorporated in a chironomid-based inference model for summer surface water temperature. Altitude varies between 4 and 2315 m a.s.l. among the lakes. Gravity corer was used to take surface samples in the deepest location for contemporary training set. To standardise the taxonomic approach, all chironomid samples taken from the Turkish lakes have compared with the European subfossil larvae collection. In total 68 different subfossil chironomids werefound. Detrended correspondence analysis (DCA) of the assemblage data were performed to identify outlying samples. Canonical correspondence analysis (CCA) was used to examine the distribution of chironomid taxa among the lakes and to relate their distributions to measured environmental variables in dataset. Weighted Averaging- Partial Least Squares (WA-PLS) were used to assess the transfer function performance. The statistics of the inference model for summer surface water temperature were analysed as RMSE = 3.03 and r2 = 0.60. These results are expected to become more consistent as the number of lakes. This study is innovative as the first Turkish chironomid-based temperature calibration set and this will offer much potential for work on temperature reconstructions in Turkey.