CO2 emission from Dianshan Lake in summer, East China

Shallow fresh water bodies in peat areas could be an important contributor to greenhouse gases in the atmosphere. In this study, the partial pressure of CO₂ in the surface water of the Dianshan Lake was investigated in-situ in August 2011. The average pCO₂ in the study area was 2300 μatm and fluctuated within the range of 989–5000 μatm. pCO₂ showed a reverse trend to the variations of pH and DO in the surface water of the Dianshan Lake. The water to air diffusion flux of CO₂ of the upstream, middle lake and downstream were respectively 63, 33 and 14 mmol/m²/d. On average, the diffusion flux of CO₂ of the whole lake was 31 mmol/m²/d. Consequently, our results show that during the sampling season, the Dianshan Lake appears to be a great source of CO₂. It is also demonstrated that respiration could be the dominant biochemical reaction in the Dianshan Lake in summer.