16 000 years of vegetation and settlement history from Egelsee (Menzingen, central Switzerland)

Past vegetation dynamics and human impact from the Lateglacial to the present are reconstructed by pollen analysis of a core 12 in long from the raised bog Egelsee, central Switzerland (770 in a.s.l.). The depth-age model of the core is based on 29 AMS C-14 dates. The oldest dated macrofinssil has an age of 13 080 +/- 105 radiocarbon yr BP (15 370 cal. yr BP); extrapolation leads to a basal age of the core of 16 200 cal. yr BP. The biostratigraphy shows a typical vegetation development for Central Europe from open pioneer vegetation to Betula-Pinus forests in the Lateglacial, thermophilous mixed deciduous forests in the early Holocene, then mesophilous Abies-Fagus forests, and finally to the present cultural landscape. The initial population expansion of Abies alba may have coincided with climatic change at c. 8500 cal. yr BP. The mass expansion of Abies alba at 8 100 cal. yr BP may have been triggered by the 8.2-ka event and coincided with the empirical limit of Fagus silvatica, indicating initial population expansions. The succession of ecosystems with different plant composition is confirmed by detrended correspondence analysis (DCA): the main changes in the DCA axis I and 2 correspond to the transition phases between the different ecosystems. DCA axis I has an eigenvalue of lambda(1) = 0.46 and is significantly correlated (r = 0.82) to the non-arboreal pollen percentage curve. Rarefaction analysis shows a high pollen diversity in the Lateglacial, lower pollen diversity in the Holocene before human impact, and increasing pollen diversity correlated with increasing human impact. Very little is known about the archaeology of the montane belt in central Switzerland. This study provides new data concerning human impact and settlement history in this area. Human activities are indicated by cereal pollen (earliest Hordeum/Triticum type at 4700 cal. yr BP). Distinct pulses of anthropogenic forest clearances can be observed from the Neolithic period onwards.