caa a22 4500 445891653 CHVBK 20180317145618.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10750-011-0869-z doi (NATIONALLICENCE)springer-10.1007/s10750-011-0869-z Subfossil chydorid (Cladocera, Chydoridae) ephippia as paleoenvironmental proxies: evidence from boreal and subarctic lakes in Finland [Elektronische Daten] [Seija Kultti, Liisa Nevalainen, Tomi Luoto, Kaarina Sarmaja-Korjonen] Chydorids (Cladocera, Chydoridae) have two reproductive strategies: asexual reproduction that prevails during favorable environmental conditions and sexual reproduction that is induced by environmental stimuli associated with seasonal or aperiodic environmental stresses. These modes of reproduction can be recognized in the subfossil sedimentary records as parthenogenetic shells of females (asexual reproduction) and by ephippia (sexual reproduction). We studied the interrelations between subfossil chydorid ephippia and environmental variables by analyzing surface sediment samples obtained from 76 Finnish lakes across a latitudinal gradient (60-70°N). The results showed that the total chydorid ephippia (TCE) increases along the climate gradient from ~2 to 3% in the south to ~25% in the north and suggested a significant dependence (r~−0.8, P<0.001) with several climate factors, especially that of mean July air temperature. We used this relationship to create a model for reconstructing past mean July air temperatures. A linear regression of the log10 transformed TCE as a single independent variable explained 76% (SE±0.76°C) of the variance of the observed mean July air temperatures. Accordingly, we propose that this novel tool may be highly suitable for reconstructing paleotemperatures in cold-temperate environments. Springer Science+Business Media B.V., 2011 Cladocera nationallicence Diapause nationallicence Gamogenesis nationallicence Fennoscandia nationallicence Fossil ephippia nationallicence Paleoclimatology nationallicence Kultti Seija Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland aut Nevalainen Liisa Institute for Limnology, Austrian Academy of Sciences, Mondseestraße 9, 5310, Mondsee, Austria aut Luoto Tomi Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland aut Sarmaja-Korjonen Kaarina Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland aut Hydrobiologia Springer Netherlands 676/1(2011-11-01), 23-37 0018-8158 676:1<23 2011 676 10750 https://doi.org/10.1007/s10750-011-0869-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-011-0869-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kultti Seija Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland aut NATIONALLICENCE 700 1- Nevalainen Liisa Institute for Limnology, Austrian Academy of Sciences, Mondseestraße 9, 5310, Mondsee, Austria aut NATIONALLICENCE 700 1- Luoto Tomi Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland aut NATIONALLICENCE 700 1- Sarmaja-Korjonen Kaarina Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, 00014, University of Helsinki, Finland aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 676/1(2011-11-01), 23-37 0018-8158 676:1<23 2011 676 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer