Automatic chamber observations of methane and carbon dioxide fluxes at West Siberian wetland

An automatic sampling and analysis system for measuring methane and carbon dioxide fluxes from soil was developed and applied to the soil flux measurements at boreal wetland near Plotnikovo in the southern part of West Siberia. The observations cover warm season (May-October) from 1998 to 2010. Measurements were performed with two systems on the two types of open wetlands typical for the area: mesotrophic open bog and patterned wetland with forested ridges, flarks and water pools. Solar powered automated system is used to open and close six static chambers equipped with air actuators. Analysis system uses improved semiconductor sensor for methane and NDIR for carbon dioxide. Seasonally averaged methane flux rate was determined to be 13 mg/m2/h at the open bog and 2 mg/m2/h at the patterned wetland. Seasonal variation of the emissions correlates well with soil temperature. On the patterned wetland, the methane fluxes show correlation with the gross CO2 uptake rate estimated from CO2 uptake by plants and nighttime respiration. The vegetation map was created from high resolution aerial photos and ground survey data. The methane and carbon dioxide fluxes appear clearly related to the vegetation and soil conditions.