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Methane emission from natural peat bogs of West Siberia and its spatial and temporal variability

Elena Veretennikova1, Egor Dyukarev1
1 laboratory of physical and climatic systems, Institute of monitoring of climatic and ecological systems SB RAS

P 3.23 in Fluxes between the atmosphere and ecosystems

Poster Session 2 on Tuesday, 16:30-18:00

The assessment of methane emission from the peat bog of different types ecosystems (pine-shrub-sphagnum community - low ryam, sedge-sphagnum fen, ridge - hollow complex and dwarf birch- sedge-hypnum swamp at from Backcharskoe bog (West Siberia) was done. CH4 fluxes were measured using a static chamber method during field trips in May, July and September, daily every 3 hours. CH4 concentration was determined by «Shimadzu GC-14B» gas chromatograph.

High level of methane emission is typical for sedge-sphagnum fen, ridge-hollow complex and dwarf- birch-sedge-hypnum swamp. Median and average estimates of methane fluxes are different. It is stipulated by a large dispersion of emission values ​​during the vegetation season. Usually there are statistically significant differences in the emission values for fen and swamp ​​in summer (July) and transitional seasons (May and September). This tendency is not observed for ryam ecosystem. The average monthly flow of methane in May at ryam  is 0.73 mgCH4/m2/h (varies from -1.07 to 2.30 mgCH4/m2/h), while on hollow and swamp prevails negative values ​​of methane fluxes. In July CH4 emission increases significantly and more evident for swamp and fen. Average July emission from all types ecosystems was 3.90 mgCH4/m2/h (varies from -3.22 to 27.15 mgCH4/m2/h). Emission decreases in September, but its value is higher than in May. The average monthly CH4 flux is 1.42 mgCH4/m2/h (ranges from -3.20 to 34.77 mgCH4/m2/h).

Daily dynamics of methane emission does not reveal any clear patterns. During a day, values ​​ changes from negative to positive. There was no synchronous variability of emission from different ecosystems. However, in a first approximation it can be noted that methane emission in the morning and afternoon from fen and hollow usually increased and ranges from 7.82 to 10.19 mgCH4/m2/h, and  at night it decreases and varies from 0.7 to 4.47 mgCH4/m2/h.

The annual total methane emission from the study area (217623 ha) is about 19486 ton. The largest contribution to the total flux belongs to fen (61.6 %) and ryam (19.1 %), other ecosystems provides contribution to the total flux less than 7 % each.

Letzte Änderung 19.06.2014