TABLE 2.
Correlations between unweighted UniFrac distances and environmental parameters (Spearman rank correlations estimated using Mantel tests)a
| Phylum (no. of soils) | Correlation
|
||||||
|---|---|---|---|---|---|---|---|
| Soil pH | Soil moisture deficit | C/N ratio | % OC | MAT (°C) | Potential C mineralization rate (μg C-CO2 g soil−1 day−1) | % Silt plus clay | |
| Full community (88) | 0.79 | 0.50 | 0.26 | 0.23 | 0.16 | 0.10 | 0.08 |
| Acidobacteria (69) | 0.72 | 0.30 | 0.05 | 0.05 | 0.11 | 0.06 | 0.20 |
| Actinobacteria (66) | 0.63 | 0.40 | 0.18 | 0.16 | 0.15 | 0.13 | 0.07 |
| Alphaproteobacteria (69) | 0.70 | 0.37 | 0.10 | 0.17 | 0.12 | 0.03 | 0.11 |
| Beta/Gammaproteobacteria (69) | 0.53 | 0.34 | 0.06 | 0.19 | 0.21 | 0.11 | 0.09 |
| Bacteroidetes (57) | 0.37 | 0.45 | 0.29 | 0.12 | 0.24 | 0.06 | 0.11 |
a
Significant correlations are indicated in bold (P < 0.01). Other soil and site characteristics that were tested but were not included in this table because there were no significant correlations (P > 0.15 in all cases) include mean annual precipitation, extractable NH4+ and NO3− levels, total microbial biomass, potential evapotranspiration, and latitude. Multivariate correlations did not increase the correlation coefficients.