Figure 2.
Effects of N2O on CO2 (A) and CH4 (B) production in anoxic Arctic tundra soil microcosms incubated at 8 °C. Replicate microcosms received no N2O (control, black squares), 0.1 mM N2O (orange triangles), and 1 mM N2O (green circles). Data represent averages from triplicate incubations with error bars showing one standard deviation. The inset in (B) shows the cumulative CH4 production during the first 15 days, and significant differences between N2O-treated and control groups at each timepoint are marked as (*) (P < 0.05). The graphs are shaded to indicate the periods when N2O was added every 2–3 days to restore the initial N2O levels (gray shaded areas) and no N2O additions after day 44 (blue shaded areas).