The Riss-Würm interglacial from West to East in the Alps: an overview of the vegetational succession and climatic development

Abstract

The vegetational and climatic developments during the Riss-Würm interglacial in the area on the northern flank of the Alps are reviewed. Reforestation seems to have begun over the whole region with a dwarf-shrub and ensuing shrub phase, leading to birch and/or pine woodland. The rise in summer temperatures, which δ180 values suggest to have been a two-stage event, permitted the immigration and expansion of more demanding trees (elm, oak, lime, ash, ivy, hazel, yew, etc.). Following the thermal maximum, which took place during the hazel and yew biozones, hornbeam dominated the forests in the alpine foreland, whilst fir/spruce forests formed the dominant vegetation at sites closer to the Alps or at a higher altitude. A marked climatic deterioration can only be recognised towards the end of the interglacial, which led to extensive spruce/pine and, finally, almost pure pine forests.