Freiburger Geographische Hefte, Vol 64

Summary

Two mires have been palynological examined. The cores were taken from the central Black Forest and from the North of Vosges. These mountain ranges are relatively close together, separated only by the Upper Rhine Valley. Both of the mires are situated to the eastern side of their respective mountain ranges.

The Black Forest bog is Plattenmoos, which has recorded the time from the Late Glacial to the Subboreal period and the younger Subatlantic period. During the Late Glacial several smaller climatic fluctuations where identified, such as the Gerzensee oscillation and the Preboreal oscillation. The beginning of the pollen profile is in the AllerØd period. During this period, the eastern Black Forest is in the transition between woodland and the treeless highland. During the Preboreal period, pine (Pinus) forests covered the eastern Black Forest and the hazelnut (Corylus) was spreading into these forests. Elm (Ulmus) and oak (Quercus) immigrated in this period. The recurrent forest fires from the Preboreal to the Atlantic period might have occurred during the Mesolithic and may be related to human activity. In the early Boreal period, lime (Tilia) immigrated. From the Boreal to the middle Atlantic period, oak, elm and lime were spreading and the eastern Black Forest was covered by a mixed oakwood (Quercetum mixtum), rich in hazelnut and pine in the middle of the Atlantic period.

Spruce (Picea) immigrated in the middle of the Atlantic period, this is earlier than the information that we have received from other central Black Forest mires. This is also earlier than spruce immigration to northern Switzerland. Because of that, a possibility of re-immigration from the east must be discussed. The possible way is from the Bavarian Forest over the Franconian mountain region and the Swabian mountains to the eastern Black Forest. But Swabian mountains have not yet been investigated, and there are not many mires.

Spruce might have spread in the late Atlanic period. In the same time, fir (Abies) immigrated to the eastern Black Forest. Beech (Fagus) immigrated at the end of the Atlantic period. The spreading of fir and beech lead to a decline of the spruce and the oakwood. During the middle Subboreal period, fir and beech forest covered the eastern Black Forest. Afterwards, pine and spruce where aided by anthropogenic land use.

In the north Vosges the Rond Pertuis supérieure have been examined. The start of the pollen profile is in the middle of the Atlantic period. A mixed oakwood rich in pine covered the north Vosges at that time. Fir and beech immigrated at the End of the Atlantic period. Soon the oakwood and the pine had been forced back by fir and beech forest.

Land use could be detected in the Young Neolithic Age. Afterwards it was continuous from the Bronze Age to now. In the late Middle Ages and the early modern era, the forest has been changed massively by anthropogenic factors. The forest had been felled, charcoal was produced. Hazelnut and birch (Betula) declined. Afterwards, fir and pine returned. Fir declined due to forestry, which introduced spruce. By now, a spruce forest covers most of the north Vosges.

The re-immigration and distribution of tree species from the mixed oakwood to the two low mountain ranges was in the same order and occurred from Boreal to Atlantic period. First immigrated elm, then oak, lime, ash (Fraxinus) and at last the maple (Acer). Elm and maple mainly spread off in the highlands. Lime distribution is located between the highlands and the lowlands. Through the course of time the development of tree species is different in the East from that in the West.