Vegetation and climate in the Early- and Pleni-Weichselian in northern central Europe

Analysis of numerous pollen diagrams from north and central Germany and fro m the adjacent lowlands of The Netherlands, Denmark, Poland and Belarus hav e facilitated a regional comparison of the vegetation and climatic evolutio n from the beginning of the Early Weichselian glaciation to the Weichselian pleniglacial. Data from geological studies and analysis of fossil beetles and plant macroremains have been used to supplement the palaeoclimatic reco nstruction. Up to the end of the Oerel Interstadial the palaeoclimate was characterised by increasing of Quaternary Science continentality. The winter temperature s in particular tended to fall continuously during the stadials and the int erstadials of the Early Weichselian and early Pleniglacial. In the Brorup a nd Odderade Interstadials summer temperatures where sufficiently high to en able boreal forests to grow, whereas in the Oerel Interstadials summer temp eratures were such that tree growth was inhibited. It is probable that fall ing sea-level and the consequent extension northwards of the North Sea coas t were the main causes of increasing continentality. In the latter part of the Pleniglacial, peat accumulation frequently took p lace and humic silts were deposited under lacustrine conditions. Correlatio n between various sites is extraordinarily difficult. Pollen diagrams from the so-called interstadials of the Glinde, Moershoofd Complex, Hengelo and Denekamp are similar to those of the known Early Weichselian stadials. It i s proposed therefore that these interstadials should be called intervals, a nd that the term interstadial be reserved for climatic variations that resu lt in distinctive pollen assemblages and which, in turn, reflect distinctiv e vegetation dynamics. Interstadials should be capable of being characteris ed on a biostratigraphical basis and it should be possible to establish cor relations over considerable distances. According to this definition, the fi rst three warm oscillations of the Weichselian glaciation in the central Eu ropean lowlands are the Brorup, Odderade and Oerel Interstadials. All other pleniglacial peat layers should be assigned the rank of interval. Copyrigh t (C) 2001 John Wiley & Sons, Ltd.