This dataset provides the raw pollen counts for the late-glacial sediment sequence retrieved from Lake Haemelsee (Germany) in 2013. The counts are presented against both depth (cm core depth) and time (cal. yr BP) and cover the time interval from ca 15.200 to 10.400 cal yr BP. A total of 106 samples were counted, with higher sampling resolution around the onset and end of the Younger Dryas, and lower sampling resolution elsewhere in the core. The pollen record provides information about both regional vegetation change as well as changes in the within-lake flora. It was produced to inform on the exact age and duration of major palynological transitions during the late-glacial Cores were retrieved from the lake using a 3-m long UWITEC piston corer deployed from a floating coring platform during field work in July 2013. Volumetric samples were obtained from splits of the core and processed in the laboratory (University of Amsterdam, the Netherlands) using standard protocols.
This study reports a precisely dated pollen record with a 20-year resolution from the varved sediments of Lake Mondsee in the north-eastern European Alps (47°49′N, 13°24′E, 481 m above sea level). The analysed part of core spans the interval between 1500 BCE and 500 CE and allows changes in vegetation composition in relation to climatic changes and human activities in the catchment to be inferred. Intervals of distinct but modest human impact are identified at ca. 1450-1220, 740-490 and 340-190 BCE and from 80 BCE to 180 CE. While the first two intervals are synchronous with prominent salt mining phases during the Bronze Age and Early Iron Age at the nearby UNESCO World Heritage Site of Hallstatt, the last two intervals fall within the Late Iron Age and Roman Imperial Era, respectively. Comparison with published records of extreme runoff events obtained from the same sediment core shows that human activities (including agriculture and logging) around Lake Mondsee were low during intervals of high flood frequency as indicated by a higher number of intercalated detrital event layers, but intensified during hydrologically stable intervals. Comparison of the pollen percentages of arboreal taxa with the stable oxygen isotope and potassium ion records of the NGRIP and GISP2 ice cores from Greenland reveals significant positive correlations for Fagus and negative correlations for Betula and Alnus. This underlines the sensitivity of vegetation around Lake Mondsee to temperature fluctuations in the North Atlantic as well as to moisture fluctuations controlled by changes in the intensity of the Siberian High and the North Atlantic Oscillation (NAO) regime.