Table 2.

The vertical spatial variations of the dominated microbial taxa at class level in the fallow and switchgrass soils, correlations between relative abundance of these taxa and soil depths were estimated via Pearson coefficient.

Class	Fallow		Switchgrass
	Pearson coefficient	P value	Pearson coefficient	P value
Gammaproteobacteria	0.598	0.040	0.603	0.038
Alphaproteobacteria	−0.372	0.233	−0.393	0.207
Acidobacteria-6	−0.186	0.562	−0.747	0.005
Betaproteobacteria	−0.541	0.069	−0.627	0.029
Clostridia	0.272	0.393	0.632	0.028
Deltaproteobacteria	−0.505	0.094	−0.476	0.118
Bacteroidia	0.197	0.539	0.593	0.042
Chloracidobacteria	−0.264	0.407	−0.699	0.011
Planctomycetia	−0.057	0.861	−0.490	0.105
Nitrospira	−0.085	0.792	−0.384	0.218
Gemmatimonadetes	−0.678	0.015	−0.468	0.125
Pedosphaerae	−0.269	0.398	−0.636	0.026
Thaumarchaeota	−0.708	0.010	−0.271	0.394
Cytophagia	−0.629	0.028	−0.671	0.017
PRR-12	0.401	0.196	−0.331	0.294
Saprospirae	−0.757	0.004	−0.767	0.004
Gemm-1	0.411	0.184	−0.084	0.794
Anaerolineae	0.101	0.755	0.255	0.423
iii1-8	−0.728	0.007	−0.494	0.102
Actinobacteria	0.389	0.212	0.536	0.073