Methanotrophy induces nitrogen fixation during peatland development

Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N-2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N-2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N-2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N-2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation.