Extended Data Fig. 10: Effect of eCO2 on the size of soil inorganic N pool in paddy rice and wetland ecosystems.
From: Inhibition of autotrophic nitrifiers in a nitrogen-rich paddy soil by elevated CO2
a and b, Soil extractable NH4+ (a) and NO3− (b) over the 2014–2018 rice growing seasons. Blue bars, aCO2. Red bars, eCO2. Data are presented with means ± standard error across treatment replicates (n = 3). c, Global distribution of the field experimental sites included in the second meta-analysis study. d, Meta-analysis of the eCO2 effect on soil nitrifiers and inorganic nitrogen pools across paddy rice and wetland ecosystems. The number of observations for each variable is shown next to the point. Error bars indicate 95% confidence interval (CI) of the mean net CO2 effect, which was calculated as the natural log of the response ratio (R), and was considered significant if 95% CI did not overlap with 0. Two-tailed Wilcoxon signed-rank test: AOB, P < 0.001; AOA, P = 0.35; NH4+, P < 0.001; NO3−, P < 0.001.
