Archaeal community changes in Lateglacial lake sediments: Evidence from ancient DNA
Journal article, 2018
The Lateglacial/early Holocene sediments from the ancient lake at Hässeldala Port, southern Sweden provide an important archive for the environmental and climatic shifts at the end of the last ice age and the transition into the present Interglacial. The existing multi-proxy data set highlights the complex interplay of physical and ecological changes in response to climatic shifts and lake status changes. Yet, it remains unclear how microorganisms, such as Archaea, which do not leave microscopic features in the sedimentary record, were affected by these climatic shifts. Here we present the metagenomic data set of Hässeldala Port with a special focus on the abundance and biodiversity of Archaea. This allows reconstructing for the first time the temporal succession of major Archaea groups between 13.9 and 10.8 ka BP by using ancient environmental DNA metagenomics and fossil archaeal cell membrane lipids. We then evaluate to which extent these findings reflect physical changes of the lake system, due to changes in lake-water summer temperature and seasonal lake-ice cover. We show that variations in archaeal composition and diversity were related to a variety of factors (e.g., changes in lake water temperature, duration of lake ice cover, rapid sediment infilling), which influenced bottom water conditions and the sediment-water interface. Methanogenic Archaea dominated during the Allerød and Younger Dryas pollen zones, when the ancient lake was likely stratified and anoxic for large parts of the year. The increase in archaeal diversity at the Younger Dryas/Holocene transition is explained by sediment infilling and formation of a mire/peatbog.
Ancient DNA
Paleoclimate
Shotgun sequencing
Paleoenvironment
Last deglaciation
Lake sediments
Lipid biomarkers
Metagenomics
Southern Sweden
Archaea
Author
Engy Ahmed
Stockholm University
Science for Life Laboratory (SciLifeLab)
Laura Parducci
Uppsala University
Per Unneberg
Uppsala University
Rasmus Ågren
Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology
CSBI
Frederik Schenk
Stockholm University
Jayne E. Rattray
Stockholm University
University of Calgary
Lu Han
Jilin University
Uppsala University
Francesco Muschitiello
Lamont-Doherty Earth Observatory
Stockholm University
Mikkel W. Pedersen
University of Cambridge
Rienk H. Smittenberg
Stockholm University
Kweku Afrifa Yamoah
Stockholm University
Tanja Slotte
Stockholm University
Science for Life Laboratory (SciLifeLab)
Barbara Wohlfarth
Stockholm University
Quaternary Science Reviews
0277-3791 (ISSN)
Vol. 181 19-29Subject Categories
Geology
Climate Research
Geosciences, Multidisciplinary
DOI
10.1016/j.quascirev.2017.11.037