Figure 1

Average well color development (AWCD) of the elevated CO2 (eCO2) and ambient CO2 (aCO2) samples in the soil depths of 0–5 cm (A) and 5–15 cm (B) measured by EcoPlate system.
Error bars indicate ± SE (standard error) of the four blocks within each depth (n = 4). *: P< 0.05; **: P< 0.01 based on t-test between aCO2 and eCO2 at each time point.