Evaluating sedimentary DNA for tracing changes in cyanobacteria dynamics from sediments spanning the last 350 years of Lake Tiefer See, NE Germany

Nwosu, Ebuka C. ORCIDiD
Brauer, Achim ORCIDiD
Kaiser, Jérôme
Horn, Fabian
Wagner, Dirk
Liebner, Susanne ORCIDiD

DOI: https://doi.org/10.1007/s10933-021-00206-9
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11048
Nwosu, Ebuka C.; Brauer, Achim; Kaiser, Jérôme; Horn, Fabian; Wagner, Dirk; Liebner, Susanne, 2021: Evaluating sedimentary DNA for tracing changes in cyanobacteria dynamics from sediments spanning the last 350 years of Lake Tiefer See, NE Germany. In: Journal of Paleolimnology, 66, 3, 279-296, DOI: https://doi.org/10.1007/s10933-021-00206-9. 
 
Nwosu, Ebuka C.; Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
Brauer, Achim; GFZ German Research Centre for Geosciences, Section Climate Dynamics and Landscape Evolution, Potsdam, Germany
Kaiser, Jérôme; Marine Geology, Leibniz Institute for Baltic Sea Research, Rostock-Warnemünde, Germany
Horn, Fabian; GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany
Wagner, Dirk; Institute of Geosciences, University of Potsdam, Potsdam, Germany
Liebner, Susanne; Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany

Abstract

Since the beginning of the Anthropocene, lacustrine biodiversity has been influenced by climate change and human activities. These factors advance the spread of harmful cyanobacteria in lakes around the world, which affects water quality and impairs the aquatic food chain. In this study, we assessed changes in cyanobacterial community dynamics via sedimentary DNA (sedaDNA) from well-dated lake sediments of Lake Tiefer See, which is part of the Klocksin Lake Chain spanning the last 350 years. Our diversity and community analysis revealed that cyanobacterial communities form clusters according to the presence or absence of varves. Based on distance-based redundancy and variation partitioning analyses (dbRDA and VPA) we identified that intensified lake circulation inferred from vegetation openness reconstructions, δ13C data (a proxy for varve preservation) and total nitrogen content were abiotic factors that significantly explained the variation in the reconstructed cyanobacterial community from Lake Tiefer See sediments. Operational taxonomic units (OTUs) assigned to Microcystis sp. and Aphanizomenon sp. were identified as potential eutrophication-driven taxa of growing importance since circa common era (ca. CE) 1920 till present. This result is corroborated by a cyanobacteria lipid biomarker analysis. Furthermore, we suggest that stronger lake circulation as indicated by non-varved sediments favoured the deposition of the non-photosynthetic cyanobacteria sister clade Sericytochromatia, whereas lake bottom anoxia as indicated by subrecent- and recent varves favoured the Melainabacteria in sediments. Our findings highlight the potential of high-resolution amplicon sequencing in investigating the dynamics of past cyanobacterial communities in lake sediments and show that lake circulation, anoxic conditions, and human-induced eutrophication are main factors explaining variations in the cyanobacteria community in Lake Tiefer See during the last 350 years.