Fig. 4From: Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China PlainCumulative CO2 emissions in each container over time among four treatments calculated from DIC (a–d) and from floating chamber measurements (e–h), the dashed lines show the exponential fits (p < 0.001) and colored areas indicate 95% confidence level, the red dots indicate the negative CO2 fluxes, namely there was CO2 uptake occurringBack to article page