Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 90. (Budapest 1998)

Medzihradszky, Zs. ; Bajzáth, J.: The occurrence of arctic-alpine Betula species in the Hungarian Pleistocene

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Volume 90. Budapest, 1998 pp. 27-33. The occurrence of arctic-alpine Betula species in the Hungarian Pleistocene Zs. MEDZIHRADSZKY

1 & J. BAJZÁTH

2 Department of Botany, Hungarian Natural History Museum H1087 Budapest, Könyves Kálmán krt. 40, Hungary 'Department of Education, Hungarian Naturcd History Museum H-1083 Budapest, Ludovika térő, Hungary MEDZIHRADSZKY, Zs. 8c BAJZÁTH, J. (1998): The occurrence of arctic-alpine Betula species in the Hungarian Pleistocene. - Annls hist.-nat Mus.natn.hung. 90: 27-33. Abstract - A rich fossil flora was found in a sandy peat layer from the Würm Glacial at Győr-Szabadrét-domb locality. This assemblage was analysed by palaeobotanical methods. From the very rich pollen- and macrofossil material we report the fossil remains of Betula nana, B. humilis and B. pubescens ssp. tortuosa. The age of this layer is 28470 ± 300 years BP dated by 14

C method. With 1 1 figures. INTRODUCTION Several years ago in the course of an archaeological excavation a thin sandy peat layer was discovered under the cultural layer at Győr-Szabadrét-domb locality (47.40°N, 17.39°E). This peat material was sampled and complete palaeobotanical study (pollen and macrofossil analysis, was carried out. Radiocarbon dating made by the Institute of Nuclear Research of the Hungarian Academy of Sciences (No. Deb.-2231) determined the age of the layer as 28470 ± 300 years BP. The complete palaeobotanical investigation discovered new and very important data that calls for modifications in the current model of the vegetational history in the Carpathian Basin. In this paper we report some of the first results. The study proved the existence of several new species {Betula nana, B. humilis and B. pubescens ssp. tortuosa) which were previously unknown in the territory of Hungary. RESULTS OF MACROFOSSIL-ANALYSIS Five Betula species were determined from the plant fossil assemblage. The macrofossil assemblage discovered at the Győr-Szabadrét-domb locality consists of remains of typical glacial species such as Dryas octopetcda, Salix herbacea, Salix polaris, Selaginella selaginoides, Koenigia islandica and birches forming a "Dryas-uom"

. Among the bir-