Net Ecosystem Exchange, Gross Primary Production And Ecosystem Respiration In Ridge-Hollow Complex At Mukhrino Bog

Abstract

The continuous field measurements of net ecosystem exchange (NEE) of CO2 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 CO2 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 CO2 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.

Keywords

• carbon dioxide
• net ecosystem exchange
• peatlands
• ridge-hollow complex
• ecosystem respiration
• gross primary production