Present address: Department of Arctic and Marine Biology, University of Tromsø, 9037 Tromsø, Norway.
Methane oxidation associated with submerged brown mosses reduces methane emissions from Siberian polygonal tundra
Article first published online: 16 MAR 2011
© 2011 The Authors. Journal of Ecology © 2011 British Ecological Society
Journal of Ecology
Volume 99, Issue 4, pages 914–922, July 2011
How to Cite
Liebner, S., Zeyer, J., Wagner, D., Schubert, C., Pfeiffer, E.-M. and Knoblauch, C. (2011), Methane oxidation associated with submerged brown mosses reduces methane emissions from Siberian polygonal tundra. Journal of Ecology, 99: 914–922. doi: 10.1111/j.1365-2745.2011.01823.x
- Issue published online: 14 JUN 2011
- Article first published online: 16 MAR 2011
- Received 21 November 2010; accepted 8 February 2011 Handling Editor: John Lee
- aquatic mosses;
- plant–microbe interaction;
- polygonal tundra;
- stable isotope probing
1. Methane (CH4) oxidation (methanotrophy) associated with submerged brown moss species occurs in polygonal tundra environments of the Siberian Arctic. Methanotrophic bacteria living in close association with mosses are thus not restricted to Sphagnum species and low-pH peatlands.
2. Moss-associated methane oxidation (MAMO) can be an effective buffer for CH4 emissions from permafrost-affected tundra, a region that is of high importance for the global greenhouse gas budget. Combining biogeochemical and molecular approaches revealed that MAMO in polygonal ponds exceeds methanotrophic activity in terrestrial sites by up to two orders of magnitude.
3. Moss-associated methane oxidation is not only promoted by submerged conditions but also by light exposure. Polygonal ponds covered by the brown moss Scorpidium scorpioides became a net sink for atmospheric CH4 (−1.7 mg CH4 m−2 day−1) when exposed to sunlight but a CH4 source (21.6 mg CH4 m−2 day−1) in the absence of light.
4. Based on stable isotope probing with 13CH4, carbon deriving from CH4 was incorporated into the bacterial fatty acids 16:1ω7 and 18:1ω9/ω7 common in methanotrophs and into plant phytol, sitosterol and stigmastanol, all of which are highly abundant in moss biomass.
5. Synthesis. A mutualistic symbiosis between methanotrophic bacteria and brown mosses reduces CH4 emissions from Arctic polygonal tundra by at least 5%. Both partners benefit from this association: the moss from the additional CO2 supplied through methane oxidation and the methane-oxidizing bacteria from the oxygen produced through photosynthesis. Considering that submerged mosses are widely abundant in the polar region, MAMO may have a major impact on carbon turnover rates in Arctic freshwater environments.