Diazotrophic methanotrophs in peatlands: the missing link?

Abstract

Commentary A recent publication in Plant and Soil (Leppanen et al. 2015) reports on the effect of peat moss species and water table on the N2 fixation rate in boreal peatlands and forests. The lack of CH4-stimulated N2 fixation led the authors to conclude that methanotrophs do not contribute significantly to the N-supply of the mosses. This is in contrast to other studies in peatlands which suggest that methanotrophs may be responsible for the “unaccounted” N-input. The importance of peatlands in the global carbon cycle, combined with the crucial role of N not only in ombotrophic peatlands but also in thawing permafrost warrants a synthesis of these controversies. Evidence for and against diazotrophic N-provision by aerobic methanotrophs in peatlands Ombrotrophic peatlands are nitrogen poor environments, relying solely on atmospheric N deposition. Yet, there is an imbalance in atmospheric N deposition and N accumulation in Sphagnum mosses, with N accumulation by far exceeding N-deposition