Plant survival in Iceland during periods of glaciation?

Aim The paper addresses the classical question of possible plant survival i n Iceland during the last glacial period in the light of a palaeobotanical record from northern Iceland, spanning the period 11,300-9000 BP, including the Younger Dryas stadial. We review the Late Cenozoic fossil plant record , the past debate on glacial plant refugia in Iceland, and the evidence for ice-free areas during the Weichselian. Location The investigated lake sediment record comes from Lake Torfadalsvat n, which is situated in the northwestern part of the Skagi peninsula in nor thern Iceland. Methods The sediment chronology was constructed from the occurrence of the Vedde Ash and the Saksunarvatn ash, two well-dated Icelandic tephras, toget her with the results from five AMS and conventional radiocarbon dates perfo rmed on bulk sediment samples. The vegetational reconstruction was based on detailed pollen analysis of the sediment sequence. Results The pollen analysis revealed that many of the taxa present in the a rea prior to the Younger Dryas stadial continued to produce pollen during t hat cold event. The more or less immediate reappearance of a few other poll en taxa at the Younger Dryas-Preboreal boundary suggests that these plants also survived, even if they did not produce sufficient pollen to be recorde d during the Younger Dryas stadial. Main conclusions We conclude that the relatively high plant diversity found in high Arctic areas and present-day nunataks in Iceland and Greenland, to gether with the fact that many plant species were able to survive the Young er Dryas stadial on the Skagi peninsula, suggest that species with high tol erance for climate fluctuations also survived the whole Weichselian in Icel and. This conclusion is supported by recent palaeoclimatic data from ice-co res and deep-sea sediments, indicating that Icelandic climate during the la st glacial was only occasionally slightly colder than during the Younger Dr yas stadial.