EGU22-11958
https://doi.org/10.5194/egusphere-egu22-11958
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Past decomposition dynamics in Arctic terrestrial environments revealed by shotgun sedaDNA

Kathleen Stoof-Leichsenring1, Amedea Perfumo1,2, Sichao Huang1, Lars Harms3, Luidmila Pestryakova4, Boris Biskaborn1, and Ulrike Herzschuh1,5,6
Kathleen Stoof-Leichsenring et al.
  • 1Polar Terrestrial Environmental Systems, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany (kathleen.stoof-leichsenring@awi.de)
  • 2Department of Physics, Freie Universität Berlin, Berlin, Germany
  • 3Computing and Data Centre, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
  • 4Institute of Natural Sciences, North-Eastern Federal University of Yakutsk, Yakutsk, Russia
  • 5Institute of Biochemistry and Biology, University Potsdam, Potsdam, Germany
  • 6Institute of Environmental Science and Geography, University Potsdam, Potsdam, Germany

Dynamics of litter decomposition in Arctic terrestrial environments control about carbon storage in permafrost soils and release of CO2 into the atmosphere. Climate warming can accelerate litter decomposition because degradational processes increase, due to shifts in types of labile organic matter available and the composition of decomposing taxa. How litter decomposition changed in former interglacial and glacial periods is rarely studied, because time-series data is lacking, but highly needed to foresee consequences of decomposition and carbon cycling for warming Arctic ecosystems. Innovative shotgun ancient DNA sequencing on sediment core samples provide a snapshot of entire components of past biotic ecosystems and deliver qualitative data on organismal and functional compositional shifts. Our study, for the first time, investigates sedimentary ancient DNA shotgun data in a 52ka sediment core from Far North-Eastern Russia, Lake Ilirney, that recovers former glacial and interglacial periods with pronounced shifts in taxonomic composition in terrestrial vegetation, microbial and fungal diversity. At the same time, the ancient DNA data provides information on gene functions, like degrading enzymes that support variation in functional composition through time. With this data, we aim to understand how litter quality, based on vegetational composition, alters the taxonomic (bacteria, fungi) and functional (enzymes involved in decomposition) community of decomposers. Our result show that glacial times are characterized by tundra vegetation, mainly herbs, accompanied with a dominance of cryophilic soil degraders and relatively lower abundance of enzymes degrading plant organic material. Interglacial periods (like late Holocene) are typified by shrub-tree and heath dominated vegetation with microbes more specialized to degrade plant material, which is supported by an increase of the relative abundance of cellulose and ligninolytic enzymes. Our preliminary results support that under future warming the expansion of shrubs and trees and the increase of specified degraders in Arctic terrestrial environments might lead to enhanced degradation of plant litter resulting in a potential increase of CO2 emissions.

How to cite: Stoof-Leichsenring, K., Perfumo, A., Huang, S., Harms, L., Pestryakova, L., Biskaborn, B., and Herzschuh, U.: Past decomposition dynamics in Arctic terrestrial environments revealed by shotgun sedaDNA, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11958, https://doi.org/10.5194/egusphere-egu22-11958, 2022.