Publication Date:
2017-11-01
Description:
We measured methane fluxes of a patterned bog from six different plant community types in three growing seasons 2012–2014 using the static chamber method. A mixed effects model was applied for quantifying the effect of the controlling factors on the methane flux. The plant community types differed from each other in their water level, total leaf area (LAITOT) and leaf area of aerenchymatous plant species (LAIAER). Excluding the highest 2.5 % of all fluxes, methane emissions ranged from −309 to 556 mg m−2 d−1. Although methane fluxes increased with increasing peat temperature, LAITOT and LAIAER, they had no correlation with water table or with plant community type. The only exception were higher fluxes from hummocks than from other plant community types in 2013. Chamber fluxes upscaled to ecosystem level for the peak season were of the same magnitude as the fluxes measured with the eddy covariance (EC) technique. In 2012 and in August 2014 there was a good agreement between the two methods, in 2013 and in July 2014, the chamber fluxes were higher than the EC fluxes. Net fluxes to soil, indicating higher methane oxidation than production, were detected every year and on all community types. Exceptionally high methane emissions up to 17 000 mg m−2 d−1 were measured sporadically in 2013 and 2014. These extreme emissions not detected in EC measurements we were not able to exclude as measurement errors and they did not correlate with any measured variables. Our results underline the importance of both LAIAER and LAITOT in controlling methane fluxes and indicate need for automatized chambers to reliably capture localized events to support more robust EC method.
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences
