LAUSR

The continuous field measurements  of net ecosystem exchange (NEE) of CO 2 were provided at ridge-hollow oligotrophic bog in the Middle Taiga zone of West Siberia, Russia  in 2017-2018. The model of net ecosystem  exchange  of CO 2 was suggested  to describe  the influence  of different  environmental  factors  on NEE and to estimate  the total carbon budget of the bog over the growing  season. The model uses air and soil temperature, incoming  photosynthetically  active radiation (PAR) and water table depth, as the key factors influencing gross primary production  (GPP) and ecosystem respiration (ER). The model coefficients were calibrated using the data collected  by automated soil CO 2 flux system with two transparent long-term  chambers  placed at large hollow and small ridge sites. Experimental and modeling results showed that the Mukhrino bog acted over the study period as a carbon  sink, with  an average NEE of –87.7 gC m -2 at the hollow site and –50.2 gC m -2 at the ridge  site. GPP was – 344.8 and –228.5 gC m -2 whereas ER was 287.6 and 140.9 gC m -2 at ridge and hollow  sites, respectively.  Despite of a large difference in NEE estimates  between 2017 and 2018 the growing  season variability  of NEE were quite similar.