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oa Diversity and Ecology of Isochrysidales in Swiss Lakes: Refining the Alkenone Paleothermometer for Mid-Latitude Lakes
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, IMOG 2025, Sep 2025, Volume 2025, p.1 - 2
Abstract
Past temperature records are key tools for inferring climate dynamics and provide empirical data for testing climate models to improve our mechanistic understanding of natural climate variability. Most of existing paleothermometers mainly provide mean annual or warm season temperatures, limiting our understanding of climate variability during the transitional seasons and winter. Alkenones are temperature-sensitive lipids produced by Isochrysidales algae, which have been used for decades to reconstruct quantitative changes in sea-surface temperatures. They have been increasingly reported in both saline and freshwater lakes worldwide, suggesting that there is great potential for alkenone-based paleotemperature reconstructions in lacustrine settings. Lacustrine alkenones have already been successfuly used to reconstruct paleotemperatures in high-latitude lakes. Before applying the alkenone proxy in freshwater mid-latitude lakes, we need to determine the seasonality of alkenone production and improve our knowledge of their producers. The monitoring of two Swiss lakes, an alpine and a lowland lake combining alkenone analysis with marker gene techniques will provide us with a better comprehension of the life cycle and diversity of Isochrysidales algae and which parameters control them. Such knowledge will be very valuable to interpret alkenone signal in sediment cores and obtain reliable paleotemperature records.
