Florengeschichtliche Beobachtungen im Nordschwarzwald (Südwestdeutschland)

Abstract

Rösch, M.; Tserendorj, G.: A natural history study of the flora of the northern Schwarzwald region,southwestern Germany. - Hercynia N. F. 44 (2011): 53 – 71.In a five-year research project supported by the German Research Council (DFG), the eight still existingcirque lakes of the Schwarzwald (Black Forest) were investigated by pollen analysis to study the humanimpact in this region from the late Neolithic Age to modern ages. In the present paper, a radiocarbondated high-resolution Holocene pollen profile from the Huzenbacher See (8°20’58” E, 48°34’32” N, 747m a. s. l.) is discussed. It shows the typical vegetation history of the region. The expansion of Abies albaand Fagus sylvatica coincides with first weak traces of human impact. The human impact intensifies inthe second and particularly in the first Millennium B. C. cal. The Iron Age deforestation is remarkable.The human impact decreases after the Roman Period, during the expansion of Carpinus betulus, and increasesagain in the early and high Medieval Period. The medieval deforestation maximum in the regionis about twofold of the Iron Age and much more extended than modern deforestation. According to thepollen profiles of the Huzenbacher See and other cirque lakes, Taxus baccata was a rather important forestcomponent in the Atlantic. Later, it was suppressed by Abies alba and afterwards by human impact.Buxus sempervirens occurs more or less regularly in the second half of the Holocene as long-distancetransported pollen grains. Hedera helix and Viscum album occur in the early Holocene but became moreseldom after the expansion of Abies. Vitis vinifera occurs already in the early Holocene, but becomesmore frequent after the Abies expansion and especially in historical times. Possible pollen sources areVitis vinifera var. sylvestris in the Upper Rhein valley, and later Vitis vinifera var. sativa from vineyardsat the western foothills of the Black Forest. The pollen grains were perhaps carried by birds. Castaneasativa occurs not before the Roman period, but from Juglans regia a single pollen grain from the earlyLatène period was found. Microspores of Isoëtes lacustris and Isoëtes echinospora are rather commonbefore the Abies expansion and became afterwards noticeably rarer.