Figure Legends
Fig. 1 Influence of addition with different types of N fertilizers on soil total microbial biomass.
Effect sizes are natural log response ratios (lnRR ), with positive and negative values indicating a positive and negative effect of N addition respectively. Points represent means (lnRR ) and error bars present 95 % confidence intervals (CI). The number in parentheses next to the bar represents the number of observations. The same below.
Fig. 2 Influence of addition with different types of N fertilizers on soil microbial characteristics.
A , Fungal biomass; B , Bacterial biomass; C , Fungi to bacteria (F/B) ratio; D , Actinomycete biomass;E , Saprophytic fungal biomass; F , Arbuscular mycorrhizal (AM) fungal biomass; G , Gram-positive (G+) bacterial biomass; H , Gram-negative (G) bacterial biomass; I , G+/G ratio.
The details of the analysis were shown in Supplementary Online Material 6 .
Fig. 3 Relationship between the changes of microbial characteristics (lnRR ) and accumulated N amount (N addition rate × application duration).
A , NH4+-N; B , NO3-N; C , NH4NO3; D , CO(NH2)2