The northwest European vegetation at the beginning of the Weichselian glacial (Brørup and Odderade interstadials)—new data for northern France

Abstract

The discovery of both the Brørup and Odderade interstadials near Watten (northern France) has given us the opportunity to construct vegetation maps for the Early Weichselian along the North Sea basin. These maps show a vegetation gradient from the Scandinavian sites to the more temperate northern France. The vegetation observed at Watten during the Brørup interstadial is a mixed forest of conifers and deciduous trees, while at the same time northwestern Europe is covered by a middle- and south-boreal forest. During the Odderade interstadial, the limit of the south-boreal and the mixed forest may be situated at Watten, while the transition from the north-boreal to the middle-boreal forest is found in the Netherlands and northern Germany. This vegetation may be related to a climatic gradient caused by several factors, such as an increasing continentality, a lowering of the sea-level, the southern deflection of the Gulf Stream and a modification of wind circulations.