LOESSFEST'09 | Aug. 31st – Sept. 3rd, 2009 |Novi Sad-Serbia
Trees or no Trees at Tokaj, Hungary?
First Alkane Biomarker Results
Schatz, A.K.1, Zech, M.2,3, Buggle, B.3, Hambach, U.2, Marković, S.B.4,
Sümegi, P.5, Scholten, T.1, Zöller, L.2
1Chair of Physical Geography and Soil Science, University of Tübingen, Rümelinstraße 19-23, 72070 Tübingen, Germany
2Chair of Geomorphology, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany
3Soil Physics Department, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany
4Chair of Physical Geography, Faculty of Sciences, University of Novi Sad, Serbia
5Department of Geology and Palaeontology, University of Szeged, 6722, Szeged, Egyetem u.2., Hungary
Large areas of Southeast Europe are covered by Pleistocene periglacial loess deposits with interbedded paleosoil layers, reflecting interglacials or -stadials during the glacial cycles. These loess-paleosol sequences are valuable terrestrial archives for paleoclimatic and paleoenvironmental information.
In recent years the traditional paradigm of treeless full-glacial paleoenvironments has increasingly been called into question, as there is palynological, anthracological and malacological evidence for the continuous presence of trees from loess-paleosol sequences in the Carpathian Basin.
We aim at contributing to this discussion by applying biogeochemical, geophysical and sedimentological methods to a loess-paleosol profile from Tokaj, Hungary, with two welldeveloped Lower and Middle Weichselian paleosols. Previous studies have focused on molluscs and charcoal, while we mainly concentrated on lipid biomarkers. Especially longchain n-alkanes (C23-C33), which form major constituents of plant leaf waxes, have successfully been used as biomarkers over the last years. Different vegetation types exhibit distinct alkane patterns. Hence, the alkane patterns in loess-paleosol sequences may serve as chemical fingerprints for the differentiation of grassland vs. shrubs and trees, and allow for a reconstruction of paleovegetation, -landscape and -climate.
In order to further complement our biomarker results and to establish a pedoand biostratigraphy, we additionally took samples for magnetic susceptibility (MS) measurements and granulometry. MS and grain size distribution may serve as proxies for the intensity of pedogenesis, weathering and paleowind strength. Finally, the organic matter is characterized by organic carbon and nitrogen measurements as well as by the determination of stable carbon and nitrogen isotopic compositions (δ13C, δ15N). The latter may give information about waterstress of the plants and opening/closing of the N-cycle.
In our talk we will present our preliminary findings and discuss them in the context of the vegetation history of the Carpathian Basin. First biomarkers results indicate that although we might not find evidence for closed woodland, there has been a small but constant population of trees and shrubs during the last 100 ka.