Methane fluxes, microbial activities and community structures in a wet tundra of the Lena Delta

• Main Authors: Wagner, Dirk, Gattinger, A., Lipski, A., Schloter, M.
• Format: Conference Object
• Language: unknown
• Published: 2005
• Subjects: Arctic; Ice; lena delta; permafrost; Tundra; wedge*; Siberia
• Online Access: https://epic.awi.de/id/eprint/12717/; https://epic.awi.de/id/eprint/12717/1/Wag2005d.pdf; https://hdl.handle.net/10013/epic.23130; https://hdl.handle.net/10013/epic.23130.d001

Wet tundra environments of the Arctic are natural sources of the climate relevant trace gas methane. The underlying biogeochemical processes are not yet well understood. The field investigations were carried out on the island Samoylov (N 72°, E 126°) located in the Lena Delta, Siberia. The study site represented an area of typical polygonal patterned grounds with ice-wedges, which were considered for analyses of methane fluxes, organic matter quality and microbial communities.The mean flux rate of the depression was 53.2 ± 8.7 mg CH4 m-2 d-1, whereas the mean flux rate of the dryer rim part of the polygon was 4.7 ± 2.5 CH4 m-2 d-1. The quantity of dissolved organic matter (DOM), which represents an important C pool for microbial communities, correlated significant with the total concentrations of phospholipid fatty acids and ether lipids (PLFA and PLEL) a measure for microbial biomass. Although permafrost soils represent a large carbon pool, it was shown, that the reduced quality of organic matter leads to a substrate limitation of the microbial metabolism. This is an important finding for modelling and calculating trace gas fluxes from permafrost environments, because the known models are consider only the total carbon amount.It can be concluded by the presented results firstly that microbial communities in permafrost environments are composed by members of all three domains of life at numbers comparable to temperate soil ecosystems and secondly that the permafrost microorganisms are well adapted to the extreme temperature gradient of their environment.