TABLE 2.
Variance of bacterial community structures explained by environmental factors, land-use type, and biogeographic region.
| Environmental factora | Pseudo-F | Explained variance [%] | Cumulative explained variance [%] |
| Soil pH | 65.6 | 29.3 | 29.3 |
| Plant ind.b for nutrients | 14.5 | 6.0 | 35.3 |
| Elevation | 7.3 | 2.9 | 38.2 |
| Clay content [%] | 5.5 | 2.1 | 40.3 |
| Bulk density [g dried finec soil/cm3] | 4.5 | 1.7 | 42.0 |
| Soil water content [%] | 4.5 | 1.6 | 43.6 |
| Plant ind.b for pH | 3.8 | 1.4 | 45.0 |
| Plant ind.b for soil moisture | 3.1 | 1.1 | 46.1 |
| Plant ind.b for variability of soil moisture | 2.6 | 0.9 | 47.0 |
| SDd of inter-annual precipitation [mm] | 2.5 | 0.9 | 47.9 |
| Land-use typee | 2.4 | 3.3 | 51.2 |
| Biogeographic regione | 1.7 | 2.8 | 50.7 |
aFactors were ranked in a step-wise forward selection using the Akaike information criterion with a p-value larger than 0.05 as exclusion criterion for the linear model, which was based on the complete dataset available for 160 sites (Supplementary Table 6).
bPlant indicator.
cSieved to 2 mm.
dMean standard deviation of monthly precipitation sums from between 1981 and 2010.
eLand-use type and biogeographic region were added individually to the model after taking into account environmental factors.