marginally significantP < 0.1
All the solid lines and dotted lines represent significant ( P < 0.05) and marginally significant (0.05 < P < 0.1, n = 32) linear regression.
All the solid lines and dotted lines represent significant ( P < 0.05) and marginally significant (0.05 < P < 0.1, n = 32) linear regression.
For different bacterial clades, two oligotrophic clades ( Alphaproteobacteria , Verrucomicrobia ) and one copiotrophic clade ( Bacteroidetes ) showed decreasing trends in the topsoil-subsoil community dissimilarities along the same gradient, whereas one oligotrophic ( Nitrospirae ) and one copiotrophic ( Gemmatimonadetes ) clade showed an increasing trend in community dissimilarity ( Fig. 2 ).