Fig. 3
Influence of ecosystem type on the individual and combined effects of N addition (N), warming (W), increased precipitation (IP), and decreased precipitation (DP) on soil CO2 emission (a), CH4 uptake (b), and N2O emission (c). The p values (p < 0.05) indicate the significance of the differences in the changes in GHG fluxes among ecosystems. Data are means with 95% confident intervals (\(\mathrm{CI}\)). The numbers of observations are shown on the right. Blue, orange, and gray solid dots indicate significantly positive, significantly negative, and non-significant effects, respectively. The vertical dashed lines are zero lines