TY - JOUR A1 - Rach, Oliver A1 - Engels, S. A1 - Kahmen, A. A1 - Brauer, Achim A1 - Martin-Puertas, C. A1 - van Geel, B. A1 - Sachse, Dirk T1 - Hydrological and ecological changes in western Europe between 3200 and 2000 years BP derived from lipid biomarker delta D values in lake Meerfelder Maar sediments JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - One of the most significant Late Holocene climate shifts occurred around 2800 years ago, when cooler and wetter climate conditions established in western Europe. This shift coincided with an abrupt change in regional atmospheric circulation between 2760 and 2560 cal years BP, which has been linked to a grand solar minimum with the same duration (the Homeric Minimum). We investigated the temporal sequence of hydroclimatic and vegetation changes across this interval of climatic change (Homeric climate oscillation) by using lipid biomarker stable hydrogen isotope ratios (ED values) and pollen assemblages from the annually-laminated sediment record from lake Meerfelder Maar (Germany). Over the investigated interval (3200-2000 varve years BP), terrestrial lipid biomarker ED showed a gradual trend to more negative values, consistent with the western Europe long-term climate trend of the Late Holocene. At ca. 2640 varve years BP we identified a strong increase in aquatic plants and algal remains, indicating a rapid change in the aquatic ecosystem superimposed on this long-term trend. Interestingly, this aquatic ecosystem change was accompanied by large changes in ED values of aquatic lipid biomarkers, such as nC(21) and nC(23) (by between 22 and 30%(0)). As these variations cannot solely be explained by hydroclimate changes, we suggest that these changes in the Wag value were influenced by changes in n-alkane source organisms. Our results illustrate that if ubiquitous aquatic lipid biomarkers are derived from a limited pool of organisms, changes in lake ecology can be a driving factor for variations on sedimentary lipid MN values, which then could be easily misinterpreted in terms of hydro climatic changes. (C) 2017 Elsevier Ltd. All rights reserved. KW - Holocene KW - Climate dynamics KW - Paleoclimatology KW - Western Europe KW - Continental biomarkers KW - Organic geochemistry KW - Stable isotopes KW - Vegetation dynamics Y1 - 2017 U6 - https://doi.org/10.1016/j.quascirev.2017.07.019 SN - 0277-3791 VL - 172 SP - 44 EP - 54 PB - Elsevier CY - Oxford ER - TY - GEN A1 - Rach, Oliver A1 - Kahmen, Ansgar A1 - Brauer, Achim A1 - Sachse, Dirk T1 - A dual-biomarker approach for quantification of changes in relative humidity from sedimentary lipid D/H ratios T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Past climatic change can be reconstructed from sedimentary archives by a number of proxies. However, few methods exist to directly estimate hydrological changes and even fewer result in quantitative data, impeding our understanding of the timing, magnitude and mechanisms of hydrological changes. Here we present a novel approach based on delta H-2 values of sedimentary lipid biomarkers in combination with plant physiological modeling to extract quantitative information on past changes in relative humidity. Our initial application to an annually laminated lacustrine sediment sequence from western Europe deposited during the Younger Dryas cold period revealed relative humidity changes of up to 15% over sub-centennial timescales, leading to major ecosystem changes, in agreement with palynological data from the region. We show that by combining organic geochemical methods and mechanistic plant physiological models on well characterized lacustrine archives it is possible to extract quantitative ecohydrological parameters from sedimentary lipid biomarker delta H-2 data. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 660 KW - delta-D values KW - hydrogen-isotopic composition KW - Dryas cold period KW - n-alkanes record KW - leaf water KW - Younger Dryas KW - seasonal variation KW - Lake sediments KW - Central Europe KW - climate varibility Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-418731 SN - 1866-8372 IS - 660 ER - TY - JOUR A1 - Rach, Oliver A1 - Kahmen, Ansgar A1 - Brauer, Achim A1 - Sachse, Dirk T1 - A dual-biomarker approach for quantification of changes in relative humidity from sedimentary lipid D/H ratios JF - Climate of the past : an interactive open access journal of the European Geosciences Union N2 - Past climatic change can be reconstructed from sedimentary archives by a number of proxies. However, few methods exist to directly estimate hydrological changes and even fewer result in quantitative data, impeding our understanding of the timing, magnitude and mechanisms of hydrological changes. Here we present a novel approach based on delta H-2 values of sedimentary lipid biomarkers in combination with plant physiological modeling to extract quantitative information on past changes in relative humidity. Our initial application to an annually laminated lacustrine sediment sequence from western Europe deposited during the Younger Dryas cold period revealed relative humidity changes of up to 15% over sub-centennial timescales, leading to major ecosystem changes, in agreement with palynological data from the region. We show that by combining organic geochemical methods and mechanistic plant physiological models on well characterized lacustrine archives it is possible to extract quantitative ecohydrological parameters from sedimentary lipid biomarker delta H-2 data. Y1 - 2017 U6 - https://doi.org/10.5194/cp-13-741-2017 SN - 1814-9324 SN - 1814-9332 VL - 13 SP - 741 EP - 757 PB - Copernicus CY - Göttingen ER -