EGU25-18039, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-18039
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
The functional diversity of microbial communities in Icelandic organic soils and its impact on carbon dynamics
Róbert Ívar Arnarsson1, Susanne Claudia Möckel2,1, Snædís Huld Björnsdóttir1, and Egill Erlendsson1
Róbert Ívar Arnarsson et al.
  • 1University of Iceland, School of Engineering and Natural Sciences, Life and Environmental Science Department, Iceland
  • 2Agricultural University of Iceland, Iceland

Andosols have the potential to store more organic carbon than any other mineral soil group. In Iceland, agricultural land commonly resides on drained peatlands which comprise of Histosols, Histic Andosols and Gleyic Andosols. The physical properties of these soils depend heavily on land-use regimes which in turn can affect the microbial life within. Bacteria and fungi are primarily responsible for processing deposited organic material into a more stable form and are also important for many other soil processes such as aggregate formation. Stressful environments can select for a more resilient microbial community at the cost of the carbon sequestration potential. For example, responses to stressful events such as droughts may select for organisms which excel in tolerance to desiccation by increasing osmolyte production at the cost of biomass production. Recalcitrant biomass may be more favourable for carbon sequestration than the maintenance-focused resource allocation. The functional traits of microbial communities can have significant impact on the carbon sequestration potential in soils. This may be of significance for agricultural land in Iceland as it often is located on drained peatlands, has rich carbon stocks, and is heavily influenced by anthropogenic activities. In this study, first of its kind for Icelandic agricultural land, we investigate the possible effects of the soil microbiome on soil carbon dynamics, and we ask what the patterns of functional diversity are at varying soil conditions. To evaluate the interplay between functional groups, land-use regimes and environmental conditions, we determine physicochemical properties of agricultural soils in Iceland, such as C and N content, C/N ratios, pH and dry bulk density. Furthermore, we determine the functional grouping of each microbial community through metagenomic analysis.

How to cite: Arnarsson, R. Í., Möckel, S. C., Björnsdóttir, S. H., and Erlendsson, E.: The functional diversity of microbial communities in Icelandic organic soils and its impact on carbon dynamics, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18039, https://doi.org/10.5194/egusphere-egu25-18039, 2025.