Plant survival in Iceland during periods of glaciation?

Abstract

SummaryAimThe paper addresses the classical question of possible plant survival in Iceland during the last glacial period in the light of a palaeobotanical record from northern Iceland, spanning the period 11,300–9000BP, 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.LocationThe investigated lake sediment record comes from Lake Torfadalsvatn, which is situated in the northwestern part of the Skagi peninsula in northern Iceland.MethodsThe sediment chronology was constructed from the cccurrence of the Vedde Ash and the Saksunarvatn ash, two well‐dated Icelandic tephras, together with the results from five AMS and conventional radiocarbon dates performed on bulk sediment samples. The vegetational reconstruction was based on detailed pollen analysis of the sediment sequence.ResultsThe pollen analysis revealed that many of the taxa present in the area prior to the Younger Dryas stadial continued to produce pollen during that cold event. The more or less immediate reappearance of a few other pollen taxa at the Younger Dryas‐Preboreal boundary suggests that these plants also survived, even if they did not produce sufficient pollen to be recorded during the Younger Dryas stadial.Main conclusionsWe conclude that the relatively high plant diversity found in high Arctic areas and present‐day nunataks in Iceland and Greenland, together with the fact that many plant species were able to survive the Younger Dryas stadial on the Skagi peninsula, suggest that species with high tolerance for climate fluctuations also survived the whole Weichselian in Iceland. This conclusion is supported by recent palaeoclimatic data from ice‐cores and deep‐sea sediments, indicating that Icelandic climate during the last glacial was only occasionally slightly colder than during the Younger Dryas stadial.