Combining Microbial DNA and Lipids to Track Glacial/Interglacial Environmental and Climate Changes: the Case of Lake Fucino
- Other Conference Item
Over glacial-interglacial timescales, land temperature has changed significantly in mid-latitude systems. In pace with these temperature changes, vegetation and soil properties (e.g. soil erosion), and the nutrient supply to freshwater systems have varied. Because of this interaction, using lacustrine sediments to reconstruct changes in both climate and environment is a challenge, but crucial in order to assess the future of lacustrine systems. To understand the interplay of environmental and climatic impacts on mid-latitude Lake Fucino, Italy (Giacco et al., 2019), we use a multi-proxy approach, based on remains of bacteria and archaea, bulk organic matter properties and XRF measurements, over several glacial/interglacial cycles (~430 ka, MIS1-MIS11). We directly reconstruct the composition of the microbial system using 16S rDNA, and track changes in the concentration of microbial matter using GDGT lipids and fatty acids. In addition, temperature and conductivity are reconstructed using the brGDGT-based MBT’5ME and CBT’ ratios. These changes in the climatic drivers on source and fate of organic matter, are framed in a XRF-based reconstruction of sediment properties. We find that glacial and interglacial sediments represent markedly different environmental systems, with different microbial communities, and distribution of GDGT lipids and fatty acids. The impact of bacterial community changes on the paleo-temperature proxy is investigated in more detail, discussing the impact of changes in the composition of the source organism, and the source (soil or lacustrine) of the GDGT lipids. Giaccio B., et al. (2019) Extending the tephra and palaeoenvironmental record of the Central Mediterranean back to 430 ka: A new core from Fucino Basin, central Italy. Quaternary Science Reviews 225, 106003. Show more
Journal / seriesAGU Fall Meeting Abstracts
Pages / Article No.
PublisherAmerican Geophysical Union
Organisational unit03868 - Eglinton, Timothy I. / Eglinton, Timothy I.
09802 - De Jonge, Cindy / De Jonge, Cindy
NotesConference lecture held on December 12, 2022.
MoreShow all metadata