Younger Dryas cold stage vegetation patterns of central Europe - climate, soil and relief controls

In the north Atlantic region the final period of the last ice age saw abrupt shifts between near present-day warm and near ice age cold conditions, ending with the cold Younger Dryas. The effects of the cold periods may have been more severe in the vicinity of the Atlantic Ocean than in continental Europe. We use pollen percentage and influx data combined with data on substrate and relief to reconstruct spatially explicit vegetation composition, patterns and development during the Younger Dryas, with special focus on to the forest/non-forest transition across NE Germany. Opposing trends, such as birch pollen percentages sharply increasing but accumulation rates sharply decreasing northwards, underline pitfalls in the interpretation of pollen percentage data in tree-line situations. The combined approach reveals a sharp ecotone. Pine declined on northern sites, possibly because of permafrost formation, but was hardly affected in the south. Birch also declined in the south, possibly because of the severe winter cold. Cold-adapted trees did not enter forest gaps. The cooling had little impact on herbal vegetation. Steppe elements (grasses, Artemisia) were largely restricted to south-exposed slopes and did not benefit from the cooling patches of steppe vegetation were even less abundant than during the preceding warm periods. The approach of combining fossil pollen data, including accumulation rates, with data on the contemporary distribution of substrate and relief allowed unprecedented spatial resolution to be reached in the reconstruction of Younger Dryas vegetation patterns.