338
Land-Ocean Systems in the Siberian Arctic: Dynamics and History
40
methane emission
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24_August1996
28. August 1996
Figure 4: Methane emission from a polygon depression due to artificial water table lowering during a field
experiment, August 1996.
To detennine the CH 4 balance in soils the methane production was measured in the polygon
depression. The production rate in the active layer calculated on the basis of the isotopic
experiments (data from 5-8 of August 1996, presented in Figure 5) was 67 mg CH 4 *d- 1*m-2
for the polygon depression and 12.9 mg CH 4 *d- l *m- 2 for the polygon wall. Acetotrophic
methane generation at the polygon depression contribute about 3.5 % of total methane
production.
The stable isotopic composition of carbon and hydrogen in methane dissolved in pore waters