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Methane emissions from an alpine fen in central Switzerland

Liebner, Susanne ; Schwarzenbach, Simon ; Zeyer, Josef

In: Biogeochemistry, 2012, vol. 109, no. 1-3, p. 287-299

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    Title
    • Methane emissions from an alpine fen in central Switzerland
    Author
    • Liebner, Susanne. Institute for Biogeochemistry and Pollutant Dynamics (IBP), Federal Institute of Technology (ETH), Universitätstrasse 16, 8092, Zurich, Switzerland
    • Schwarzenbach, Simon. Institute for Biogeochemistry and Pollutant Dynamics (IBP), Federal Institute of Technology (ETH), Universitätstrasse 16, 8092, Zurich, Switzerland
    • Zeyer, Josef. Institute for Biogeochemistry and Pollutant Dynamics (IBP), Federal Institute of Technology (ETH), Universitätstrasse 16, 8092, Zurich, Switzerland
    Document Type
    • Postprint
    OAI-PMH Identifier
    • oai:doc.rero.ch:321797
    Summary
    Methane emissions and below ground methane pore water concentrations were determined in an alpine fen at 1,915m a.s.l. in central Switzerland. The fen represented an acidic (pH 4.5-4.9), nutrient-poor to mesotrophic habitat dominated by Carex limosa, Carex rostrata, Trichophorum caespitosum and Sphagnum species. From late fall to late spring the fen was snow-covered. Throughout winter the temperatures never dropped below 0°C at 5cm below the vegetation surface. Methane emissions in June, July, August and September were in the range of 125 (±26)-313 (±71)mgCH4m−2day−1 with a tendency to decrease along the summer season. Mean methane pore water concentrations at a depth of 20-40cm below the vegetation surface were 526 (±32)μM in June and in the range of 144 (±10)-233 (±7)μM in July, August and September. At a depth of 0-20cm the mean methane pore water concentrations dropped back to <20μM with an almost linear decrease between 0 and 15cm. Oxygen pore water concentrations were close to air saturation in the first few centimeters and dropped back below detection limit at a depth of 20cm. In July and August the pore water concentrations of dissolved organic carbon (DOC) were in the range of 7.2-10.1mgCl−1 at all depths. The pore water concentrations of acetate, formate and oxalate were in the range of 2.0-8.2μM at all depths. Methanotrophic and methanogenic communities were quantified using pmoA and mcrA, respectively, as marker genes. The abundances of both communities showed a distinct peak at a depth of 10-15cm below the vegetation surface