Archaeal community changes in Lateglacial lake sediments: Evidence from ancient DNA
Artikel i vetenskaplig tidskrift, 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.

Paleoenvironment

Metagenomics

Paleoclimate

Last deglaciation

Southern Sweden

Lake sediments

Ancient DNA

Archaea

Lipid biomarkers

Shotgun sequencing

Författare

Engy Ahmed

Stockholms universitet

Science for Life Laboratory

Laura Parducci

Uppsala universitet

Per Unneberg

Uppsala universitet

Rasmus Ågren

CSBI

Frederik Schenk

Stockholms universitet

Jayne E. Rattray

Stockholms universitet

University of Calgary

Lu Han

Uppsala universitet

Jilin University

Francesco Muschitiello

Lamont-Doherty Earth Observatory

Stockholms universitet

Mikkel W. Pedersen

University of Cambridge

Rienk H. Smittenberg

Stockholms universitet

Kweku Afrifa Yamoah

Stockholms universitet

Tanja Slotte

Stockholms universitet

Science for Life Laboratory

Barbara Wohlfarth

Stockholms universitet

Quaternary Science Reviews

0277-3791 (ISSN)

Vol. 181 19-29

Ämneskategorier

Geologi

Klimatforskning

Multidisciplinär geovetenskap

DOI

10.1016/j.quascirev.2017.11.037

Mer information

Senast uppdaterat

2018-05-30