Fig. 4
Spearman correlation matrix between soil physicochemical characteristics and bacterial communities at phylum level a and genus level b. N: soil nitrogen content, C: soil carbon content, P: soil phosphorus content, NO3−-N: soil nitrate content, NH4+-N: soil ammonium content, A.N: available nitrogen content, A.P: available phosphorus content, Ca: soil exchangeable calcium content, Mg: soil exchangeable magnesium content, K: soil exchangeable potassium, SOM: soil organic matter. *P < 0.05, ** P < 0.01