PNNL

Abstract

Microbiomes and their metabolites play a crucial role in ecosystems, yet understanding their impact on greenhouse gas emissions from thawing permafrost remains poorly understood. Here we analyzed microbial and metabolite composition across a permafrost thaw gradient in Stordalen Mire, Sweden. Our study revealed divergence between microbial assembly and metabolomic dynamics across habitats. A detailed feature-scale analysis illuminated nuanced interactions among microbial lineages and metabolite formulas, revealing significant contributors. Relationships between microbial assembly, the metabolome, and CO2/CH4 porewater concentrations underscored the need for considering fine-scale interactions in ecosystem studies. These insights deepen our understanding of permafrost peatlands and community metabolism, vital for refining ecosystem models. However, the observed divergence between microbial assembly and metabolite pools, possibly influenced by interaction delays or non-biological factors, pose challenges to predictive modeling. Overall, our elucidation of assembly processes underlying microbe-metabolite interactions advances our ability to forecast greenhouse gas trajectories from thawing permafrost.