Adaptation, spatial variability, and phylogenetic characterization of methanotrophic communities in permafrost soils of the Lena Delta, Siberia

• Other Authors: Liebner, Susanne (VerfasserIn)
• Format: Text
• Language: English
• Published: Niedersächsische Staats- und Universitätsbibliothek 2007
• Subjects: ggo; Arctic; lena delta; permafrost; Tundra; Siberia
• Online Access: http://webdoc.sub.gwdg.de/ebook/dissts/Bremen/Liebner2007.pdf; http://nbn-resolving.de/urn:nbn:de:gbv:46-diss000109214

Methane, permafrost, Siberia, bacteria, diversity, adaptation, pmoA, clone libraries. - The Lena Delta, located in north-east Siberia in the zone of continuous permafrost, is the largest delta within the circum-arctic. The natural capacity of arctic wetlands underlain by permafrost to emit methane is currently of major concern in the context of global change, because arctic permafrost is particularly susceptible to degradation. Permafrost degradation is suggested to impose huge amounts of yet stored carbon to the atmosphere and with this to cause a positive feedback on the natural methane source strength of Siberian wetlands and tundra. An understanding of the processes that determine methane emissions in these environments is therefore essential not only for present but also for future balancing and modeling of their methane fluxes, in particular with regard to the pronounced morphological heterogeneity of polygonal tundra habitats. The ability of aerobic methane oxidizing (methanotrophic) bacteria (MOB) to function as the primary sink for methane in terrestrial habitats set the frame of the present work. Its main objective was to study the ecology of MOB in morphological units that are representative for the polygonal tundra of the Lena Delta. The particular focus was on the adaptation, spatial variability, and phylogenetic characterization of MOB in relation to the changing environmental conditions of polygonal tundra environments. The community of MOB in polygonal tundra sites of the Lena Delta was observed to be specialized to the extreme temperature regime it is exposed to. Firstly, in sites where the abundance of MOB was not limited by the availability of oxygen, MOB contributed partly more . @Bremen, Univ., Diss., 2007