First Calibration and Application of Leaf Wax n -Alkane Biomarkers in Loess-Paleosol Sequences and Modern Plants and Soils in Armenia

• Published in: Geosciences
• Main Authors: Yesmine Trigui, Daniel Wolf, Lilit Sahakyan, Hayk Hovakimyan, Kristina Sahakyan, Roland Zech, Markus Fuchs, Tilmann Wolpert, Michael Zech, Dominik Faust
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2019
• Subjects: Lesser Caucasus; Armenia; leaf wax biomarker; n -alkane; loess; paleosol; Paleo-environment; Geology; QE1-996.5; Tundra
• Online Access: https://doi.org/10.3390/geosciences9060263; https://doaj.org/article/e93733c88878479aa35c67945029908c

Interpreting paleoenvironmental conditions by means of n -alkane biomarker analyses is challenging because results depend on different influencing factors. Thus, regional calibration of n -alkane patterns is needed because of different plant chemo-taxonomic behavior. We investigated for the first-time leaf wax-derived n -alkane biomarkers from modern plants, litter, top soils, and two recently discovered loess-paleosol sequences (LPSs) in Armenia (Lesser Caucasus). Our results on modern samples show a promising discrimination power based on n -alkane chain length nC 33 (probably nC 31 )) for grasses and herbs versus nC 29 for deciduous trees, despite the large interplant variability within vegetation groups. In contrast with other Loess records in Europe, where Late Pleistocene environments are ranging from tundra-like (glacial) to deciduous forest habitats (interglacial), our results from two Armenian LPSs suggest a transition from humid-steppe biome or forest-steppe vegetation dominating during interglacial periods, to semi-desert shrubs species more adapted to the enhanced aridity during glacial periods.