A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Division of Chemistry and Division of Materials Research through Cooperative Agreement No. DMR-1644779 and the State of Florida. All software used for FT_ICR MS data processing are publicaly available: https://nationalmaglab.org/user-facilities/icr/icr-software We are grateful for assistance in field work and sampling by Sara Anthony and the Arctic Research station (Abisko Sweden), especially thankful to Jennie Wikström, Eric Lundin, Niklas Rakos and Alexander Meire. We are thankful for providing the gas chambers with the plastic lids by Mette Svenning (Arctic University of Norway, Tromsø, Norway). We thank Miroslava Malusova and Katrin Wunsch for assistance in the lab and Timm Bayer for his help during SEM analysis. We further thank QBIC (Quantitative Biology Center, University of Tuebingen) for assistance in interpreting the 16S rRNA amplicon sequences. This work was supported by the University of Tuebingen (Programme for the Promotion of Junior Researchers award to Casey Bryce) and by the German Academic Scholar Foundation (scholarship to Monique Patzner). Published work associated with this data can be found at https://doi.org/10.1038/s43247-022-00407-8