Assessing the responses of Sphagnum micro-eukaryotes to climate changes using high throughput sequencing

Monika K Reczuga; Christophe Victor William Seppey; Matthieu Mulot; Vincent E J Jassey; Alexandre Buttler; Sandra Słowińska; Michał Słowiński; Enrique Lara; Mariusz Lamentowicz; Edward A D Mitchell

doi:10.7717/peerj.9821

Assessing the responses of Sphagnum micro-eukaryotes to climate changes using high throughput sequencing

PeerJ. 2020 Sep 18:8:e9821. doi: 10.7717/peerj.9821. eCollection 2020.

Authors

Monika K Reczuga^{1

2

3}, Christophe Victor William Seppey^{2

4}, Matthieu Mulot², Vincent E J Jassey^{5

6

7}, Alexandre Buttler^{6

7}, Sandra Słowińska⁸, Michał Słowiński⁹, Enrique Lara^{2

10}, Mariusz Lamentowicz¹, Edward A D Mitchell^{2

11}

Affiliations

¹ Climate Change Ecology Research Unit, Faculty of Geographical and Geological Sciences, Adam Mickiewicz University, Poznań, Poland.
² Laboratory of Soil Biodiversity, University of Neuchâtel, Neuchâtel, Switzerland.
³ Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
⁴ Department of Arctic and Marine Biology, Faculty of Biosciences Fisheries and Economics, University of Tromsø, Tromsø, Norway.
⁵ Laboratoire Ecologie Fonctionelle et Environnement, Université de Toulouse, CNRS, Toulouse Cedex, France.
⁶ Ecological Systems Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
⁷ Swiss Federal Institute for Forest, Snow and Landscape Research, Site Lausanne, Switzerland.
⁸ Department of Geoecology and Climatology, Institute of Geography and Spatial Organization, Polish Academy of Sciences, Warsaw, Poland.
⁹ Past Landscape Dynamics Laboratory, Institute of Geography and Spatial Organization, Polish Academy of Sciences, Warsaw, Poland.
¹⁰ Real Jardín Botánico, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
¹¹ Jardin Botanique de Neuchâtel, Neuchâtel, Switzerland.

Abstract

Current projections suggest that climate warming will be accompanied by more frequent and severe drought events. Peatlands store ca. one third of the world's soil organic carbon. Warming and drought may cause peatlands to become carbon sources through stimulation of microbial activity increasing ecosystem respiration, with positive feedback effect on global warming. Micro-eukaryotes play a key role in the carbon cycle through food web interactions and therefore, alterations in their community structure and diversity may affect ecosystem functioning and could reflect these changes. We assessed the diversity and community composition of Sphagnum-associated eukaryotic microorganisms inhabiting peatlands and their response to experimental drought and warming using high throughput sequencing of environmental DNA. Under drier conditions, micro-eukaryotic diversity decreased, the relative abundance of autotrophs increased and that of osmotrophs (including Fungi and Peronosporomycetes) decreased. Furthermore, we identified climate change indicators that could be used as early indicators of change in peatland microbial communities and ecosystem functioning. The changes we observed indicate a shift towards a more "terrestrial" community in response to drought, in line with observed changes in the functioning of the ecosystem.

Keywords: Biodiversity; Community structure; Food-web; Protists; Warming; Water table manipulation; Wetlands.

Grants and funding

This research was funded by grants from Switzerland through the Swiss Contribution to the enlarged European Union (Project CLIMPEAT: PSPB-013/2010), the National Science Centre, Poland (Grant no.: 2015/19/N/NZ8/00172) and the program ‘Atracción de talentos de la Comunidad de Madrid’ (grant 2017-T1/AMB-5210 4). Monika K. Reczuga was supported by a SCIEX fellowship (grant no 13.311). Christophe Victor William Seppey was funded by the Research Council of Norway (Climarctic project 270252, and Methanobase 256132). The open access fee was funded from the resources of the School of Natural Sciences of the Adam Mickiewicz University, Poznań. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.