EGU24-16476, updated on 09 Mar 2024
https://doi.org/10.5194/egusphere-egu24-16476
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Sedimentary ancient DNA connects land carbon sources and marine carbon sinks

Ulrike Herzschuh1,2, Josefine Weiß1, Kathleen Stoof-Leichsenring1, Lars Harms1, Dirk Nuernberg3, and Juliane Mueller1,4
Ulrike Herzschuh et al.
  • 1Alfred Wegener Institute, Research Unit Potsdam, Potsdam, Germany (ulrike.herzschuh@awi.de)
  • 2University of Potsdam
  • 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Ocean circulation and climate dynamics, Kiel, Germany
  • 4Department of Geosciences, University of Bremen, Bremen, Germany

Marine sediments contain abundant organic matter which forms a major carbon sink. About one third of it originates from land plants. The main source taxa and source region as well as the large-scale translocation are hitherto poorly understood, mainly because we lack a proxy that can identify the source taxa with high taxonomic resolution. Here, we investigate the land plant component of sedimentary ancient DNA in six globally distributed marine sediment cores as a proxy for the terrestrial organic matter quantity and preservation as well as the source taxa. The spatial and temporal plant composition reflects mainly the vegetation composition and dynamics from the nearby continents as revealed by pollen records. However, we also find indications of a global north-to-south translocation of organic matter. The plant composition shows that upland vegetation is strongly underrepresented compared to riverine and coastal sources and there is a high contribution from mosses and ferns, particularly at high latitudes during the Holocene. We find that plant matter has a higher share and is better preserved in samples from the Late Glacial, which is characterized by high runoff and mineral load. Our results suggest that plant DNA in marine sediments may provide the missing proxy that links terrestrial plant sources to marine sedimentary carbon sinks. This represents the basis of how climate change and land-use change translates into carbon-sink dynamics and also informs about natural carbon-capture solutions.

How to cite: Herzschuh, U., Weiß, J., Stoof-Leichsenring, K., Harms, L., Nuernberg, D., and Mueller, J.: Sedimentary ancient DNA connects land carbon sources and marine carbon sinks, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16476, https://doi.org/10.5194/egusphere-egu24-16476, 2024.

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