Plant-mediated root methane emissions and oxidation in a thermokarst bog complex in the Bonanza Creek LTER Experimental Forest IV - Oxic and Anoxic Methane Fluxes on Isolated Carex Plants 2015

Vascular plants are important in the wetland methane cycle but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. Vegetation operated on top of baseline methane emissions, which varied with proximity to the thawing permafrost margin. Emissions from vegetated plots increased over the season, resulting in cumulative seasonal methane emissions that were 4.1-5.2 g m-2 season-1 greater than unvegetated plots. Mass balance calculations signify these greater emissions were due to increased methane production (3.0-3.5 g m-2 season-1) and decreased methane oxidation (1.1-1.6 g m-2 season-1). Minimal oxidation occurred along the plant-transport pathway and oxidation was suppressed outside the plant pathway. Our data indicate suppression of methane oxidation was stimulated by root exudates fueling competition among microbes for electron acceptors. Root exudates are known to fuel methane production and our work provides evidence they also decrease methane oxidation. This dataset contains 2015 monthly methane fluxes from isolated Carex plants in a bog complex in the Bonanza Creek LTER. Isolated plant fluxes were used to partition the flux from the plant mediated pathway.