Lateglacial and Holocene vegetation dynamics in the Aegean region: an integrated view based on pollen data from marine and terrestrial archives

Abstract

To elucidate the vegetation dynamics in the Aegean region during the last 20 kyr, we have studied terrestrial palynomorphs in marine core GeoTü SL152 (Mount Athos Basin, northern Aegean Sea) at centennial-scale (125 to 300 yr) resolution. The robust chronology of the core allows us to reliably date signals of short-term vegetation change in the Aegean region. For the Pleniglacial interval until ~14.6 kyr BP, our data document steppe vegetation, suggesting dry climatic conditions in the borderlands of the Aegean Sea. Subaerially exposed parts of the shelf were probably colonized by Pinus-dominated vegetation until shelf areas were flooded during Lateglacial sea-level rise. The final, rapid decrease of Pinus pollen percentages between ~14 and ~13 kyr BP appears to be connected to meltwater pulse MWP-1A. The Lateglacial interstadial complex (ie, Meiendorf, Bølling and Allerød) is characterized by the spread of oak trees, but also by the continuous presence of steppe elements, indicating only slightly increased humidity. The Younger Dryas chronozone was the driest interval of the past 20 kyr. Insufficient humidity was most likely also responsible for the ~2.0 kyr delay in Holocene reforestation in the Aegean region relative to western Greece. During the Holocene, the vegetation was repeatedly affected by centennial-scale episodes of reduced moisture availability. Radiocarbon-based age models of previously published pollen records imply strong discrepancies in vegetation development in the Aegean region, but there are reasons to doubt the accuracy of these age models. Here we use the well-dated pollen record from marine core SL152 and biostratigraphic correlation to propose revised chronologies for several published terrestrial pollen records. This re-assessment yields a spatiotemporally consistent pattern of vegetation dynamics in the borderlands of the Aegean Sea.