Fäjmyr dataset

This dataset comprises methane (CH₄) and carbon dioxide (CO₂) flux measurements and associated microbial community data from nine peat–plant mesocosms collected from an ombrotrophic bog in southern Sweden. All mesocosms were dominated by Eriophorum vaginatum and maintained under controlled environmental conditions, including constant temperature, light regime, and water table depth. Gas fluxes (CH₄ and CO₂) were measured repeatedly using static chamber techniques, and mean CH₄ flux per mesocosm was used to define a gradient of methane emissions (hereafter “CH₄ emission order”, 1–9 from lowest to highest emission). Associated CO₂ flux components (ecosystem respiration, gross primary productivity, and net ecosystem exchange) are included for each measurement. Microbial community composition was characterised using captured metagenomics targeting genes within the methane metabolism pathway (KEGG ko:00680). Peat samples were collected from three depth-related microenvironments within each mesocosm (oxic–anoxic interface, bulk peat, and rhizosphere), resulting in 27 samples. Sequencing data were processed to obtain genus-level taxonomic profiles of methane-cycling microorganisms, including methanogenic Archaea and methanotrophic bacteria. The dataset includes: processed CH₄ and CO₂ fluxes Genus-level relative abundance tables for methane-cycling taxa