Zur Pollenanalyse von Lössen: Untersuchungen der Lößprofile von Oberfellabrunn und Stillfried (Niederösterreich)

Abstract

A method for pollenanalytical investigations of loesses is described. If several sources of error are duely taken into consideration, this method is successful in the reconstruction of the vegetation history of those phases of pleniglacial times, during which the thick loess layers were accumulated. The method can be employed in pollenanalytical investigations of weathered and unweathered loesses, with the exception of redeposited loesses. It can be shown that the famous sequence of fossil soils at Oberfellabrunn, known as the soils of the "Fellabrunner Komplex" („Stillfried A"), which is sometimes held to be the equivalent of the "Göttweig Interstadial", must be divided into the brown loamy soil at the base of the sequence, which was formed during the Eemian Interglacial, and into the younger humic layers, which developed during the Interstadials of Amersfoort and Brørup. The amelioration of climate during the "Stillfried B-Interstadial" (perhaps equivalent of the "Paudorf Interstadial"?) was strong enough to enable local subalpine conifer forests and riverine broad-leaved forests to spread along the rivers and other suitable places within the still dominant steppe formations on the drier loess plateaus. The loess layers of the Riss and Würm glaciations have been accumulated within the eastern Dart of Niederösterreich in different steppe communities, which can be described at best as belonging to the Gramineae steppe formation, rich in herbaceous plants. Sometimes there occurred plants of recent tundra-communities in the loess steppe: but real tundras did not exist at that time in Niederösterreich. This holds true most of all for the last period of loess accumulation after the Stillfried B-Interstadial. When being compared with pollen spectra of surface samples of recent tundra, steppe and semidesert plant communities, it becomes evident, that the open vegetation, thriving during the last glaciation in vast regions of Northern Eurasia cannot be described in terms of modern plant associations.