Palynology and natural environment in the Pannonian to Holocene sediments of the Early Medieval centre Pohansko near Břeclav (Czech Republic)

Pohansko (Czech Republic) is an important Early Medieval centre of the Great Moravian Empire (9th century AD). The locality has a settlement with archaeological findings from Mesolithic to the modern times.The studied sediments belong to the stream and flood deposits of the Dyje river, aeolian sands and buried soils. The lower parts of some boreholes penetrated into the Upper Miocene sediments. 172 samples were palynologically analysed. The original forest with relative small human impact was observed on the base of Holocene layers. Even sporadic Cerealia pollen were found here. A deforestation was visible in the cultural layer; it is linked with existence of the Great Moravian agglomeration and its fortification. Later, a partial forest reconstruction probably took place in the surroundings. Very abundant pollen of human-exploited plants (cereals, herbs) were discovered in the filling of archeological feature O1. The possible practical potential of rampart also as the flooding protection was indicated by the existence of marshy plants palynomorphs. The existence of oxbow was proved in the excavated probe S3. The lowermost sample was dated by 14C as 7830 ± 60 BP. The findings of Carpinus pollen in the layer dated as Early Atlantic support the earlier spreading of this genus in the Czech Republic (i.e. South Moravia).