EGU2020-19336
https://doi.org/10.5194/egusphere-egu2020-19336
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Holocene plant community changes in the Western Alps, as inferred from sedaDNA

Sandra Garces Pastor1, Peter D. Heintzman1, Youri Lammers1, Scarlett Zetter1, Antony Gavin Brown1,2, Kevin Walsh3, Charline Giguet Covex4, Willy Tinner5, Christoph Schwörer5, Oliver Heiri6, Sébastien Lavergne7, Eric Coissac7, Boris Vannière8, Isabelle Jouffroy-Bapicot8, Andreas Tribsch9, and Inger G. Alsos1
Sandra Garces Pastor et al.
  • 1The Arctic University Museum of Norway, UiT– The Arctic University of Norway, Tromsø, Norway.
  • 2School of Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
  • 3Department of Archaeology, University of York, York, UK.
  • 4CNRS, Université Savoie Mont Blanc, France.
  • 5Palaeoecology, Institute of Plant Sciences & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
  • 6Geoecology, Department of Environmental Sciences, University of Basel, Basel, Switzerland.
  • 7University Grenoble-Alpes · Laboratoire d'écologie alpine (LECA) · MALBIO France · Grenoble, Rhône-Alpes
  • 8CNRS, Chrono-environnement UMR 6249 and MSHE USR 3124, Université Bourgogne Franche-Comté, F-25000 Besançon, France
  • 9University of Salzburg · Department of Biosciences, Salzburg, Austria

Climate change has already started to rapidly transform ecosystems. Predicted scenarios of future ecosystem changes inferred from contemporary ecological data may be uncertain, as these records do not provide the temporal depth needed to understand how ecosystems have responded to past periods of climatic changes and human pressure. However, palaeoecological approaches allow for the reconstruction of past ecosystem changes, including the composition of plant communities, thereby enabling researchers to improve models of future climatic change impacts.

Lakes located in high-mountain ranges, such as the Alps, are suitable ecosystems for studying long-term species turnover and environmental shifts driven by past climate changes, as they preserve a wealth of palaeoecological information in its sediment archives. The Alpine ecosystems are expected to be affected by ongoing climate warming, prompting an upward displacement of vegetation, elevated replacement rates and species losses, with projected increased intensity of impacts in the future.

Previous studies of the Alps have used pollen and macrofossil evidence to infer past vegetation dynamics. However, microscopic morphological determinations are time-consuming and some inferences have been limited by low taxonomic resolution and the biased preservation of identifiable remains. Ancient DNA from organisms is also often preserved in the sediment (sedaDNA), which can rapidly be detected and analysed using metabarcoding approaches. Together with a novel, region-specific barcode reference database for the flora of the Alps (PhyloAlps; 4500 taxa), we can bypass the morphological limitations of previous palaeobotanical studies and refine taxonomic resolution, often to the species level.

To investigate the origin and impact of past environmental changes in alpine ecosystems throughout the Holocene, we performed a multi-proxy reconstruction of 9 lake sediment cores from the Western Alps (France, Italy and Switzerland). Using metabarcoding, we reconstructed the plant community composition and used XRF, magnetic susceptibility, and loss-on-ignition data to understand lacustrine dynamics during the Holocene for each lake. We will present the major findings from these analysed records, the general ecosystem shifts inferred, and the impacts of perturbations caused by human pressure and climatic changes.

How to cite: Garces Pastor, S., D. Heintzman, P., Lammers, Y., Zetter, S., Gavin Brown, A., Walsh, K., Giguet Covex, C., Tinner, W., Schwörer, C., Heiri, O., Lavergne, S., Coissac, E., Vannière, B., Jouffroy-Bapicot, I., Tribsch, A., and G. Alsos, I.: Holocene plant community changes in the Western Alps, as inferred from sedaDNA , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19336, https://doi.org/10.5194/egusphere-egu2020-19336, 2020

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  • CC1: Comment on EGU2020-19336, Kathleen Stoof-Leichsenring, 05 May 2020

    Dear Sandra,

    Your cores cover the last decades/centuries of lakes history, as far as I can see. They look all very similar at a first glance. What would you say are the major changes throughout this time period?

    Thanks Kathleen