Microbial activity contributes to spatial heterogeneity of wetland methane fluxes

Globally, wetlands are one of the largest sources of methane (CH₄), a greenhouse gas with a warming impact significantly greater than CO₂. Methane produced in wetlands is the byproduct of a group of microorganisms which convert organic carbon into CH₄. Despite our knowledge of how this process works, it is still unclear what drives dramatic, localized (<10 m) variance in emission rates from the surface of wetlands. While environmental conditions, like soil temperature or water table depth, correlate with methane flux when variance in these factors is large (e.g., spring vs fall), the explanatory power of these variables decline when spatial and temporal scales become smaller. As methane fluxes are the direct product of microbial activity, we profiled how the microbial community varied, both horizontally and vertically, across a peat bog in Maine, USA, finding that variance in microbial communities was likely contributing to much of the observed variance in flux.