Evaluation of the regional vegetation and climate in the Eastern Alps (Austria) during MIS 3–4 based on pollen analysis of the classical Baumkirchen paleolake sequence

Abstract

AbstractThe pre-last glacial maximum paleolake sediments at Baumkirchen, western Austria, are well known in Alpine Quaternary stratigraphy as being the type locality of the Middle to Upper Würmian transition. Their location provides a rare opportunity to investigate the vegetation history of the interior of the Alps during the last glacial cycle. A recent renewed research effort involving new drilling revealed a 250-m-thick lacustrine sequence with an older, ca. Marine Oxygen Isotope Stage (MIS) 4 phase and a younger, mid- to late MIS 3 phase. Pollen analysis reveals generally poor preservation and very low pollen concentration due to very high sedimentation rates. On the basis of pollen percentages and influx rates, six pollen zones (PZ) were assigned. PZ1 and 2 correspond to the entire ca. MIS 4 section and are characterized by only scattered vegetation representing an extremely cold and dry climate. Two stadials and two interstadials were identified in the MIS 3 section. The interstadials are characterized by well-developed open vegetation with some stands of trees, with the upper PZ6 being better developed but still forest-free. On the basis of previous radiocarbon dating, this zone (PZ6) is correlated to Greenland Interstadial (GI) 7 and the lower interstadial (PZ4) tentatively to GI 8.