Table 3.
Test statistics of the linear models used to explore effects of drought and diversity treatments on AMF performance.
| Explanatory variables | Arbuscule abundance | Vesicle abundance | Mycorrhiza frequency | ||||
|---|---|---|---|---|---|---|---|
| D.f. | F | p | F | p | F | p | |
| Drought | 1 | 27.23 | <0.001 | 17.81 | <0.001 | 25.09 | <0.001 |
| Barley richness | 1 | 34.05 | <0.001 | 7.84 | 0.006 | 7.99 | 0.005 |
| AMF richness | 1 | 20.42 | <0.001 | 34.72 | <0.001 | 8.86 | 0.003 |
| Colonization frequency | 1 | 110.00 | <0.001 | 139.54 | <0.001 | X | X |
| Drought: barley richness | 1 | 0.23 | 0.63 | 1.06 | 0.30 | 0.28 | 0.60 |
| Drought: AMF richness | 1 | 0.10 | 0.75 | 0.99 | 0.32 | 0.95 | 0.33 |
| Drought: colonization frequency | 1 | 1.19 | 0.28 | 0.50 | 0.48 | X | X |
| Barley richness: AMF richness | 1 | 4.06 | 0.046 | 2.60 | 0.11 | 2.41 | 0.12 |
| Barley richness: colonization frequency | 1 | 5.12 | 0.025 | 1.39 | 0.24 | X | X |
| AMF richness: colonization frequency | 1 | 0.18 | 0.68 | 1.38 | 0.24 | X | X |
| Drought: barley richness: AMF richness | 1 | 3.18 | 0.08 | 5.97 | 0.016 | 0.00 | 0.97 |
| Drought: barley richness: Colonization frequency | 1 | 1.94 | 0.17 | 0.66 | 0.42 | X | X |
| Drought: AMF richness: colonization frequency | 1 | 1.74 | 0.19 | 0.01 | 0.94 | X | X |
| Barley richness: AMF richness: colonization frequency | 1 | 1.68 | 0.20 | 4.56 | 0.034 | X | X |
| Adjusted R2 | 0.5667 | 0.5664 | 0.1973 | ||||
| No. observations | 158 | 158 | 158 | ||||
The table shows degrees of freedom (D.f.), values of F statistic (F) and p values (p) for each main effect and interactions up to the 3rd order. Significant p values (p < 0.05) are highlighted in bold. Symbol X stands for the significance of the main effects and interactions which could not be calculated when mycorrhiza colonization frequency was used as the response variable. Barley and AMF richness are treated as linear terms.