Table 3. ANOVA estimates, F- and P-values of the relative proportion of the explained variation accounted for by biotic (vs abiotic) variables in redundancy analyses (RDA) of graminoid and forb species composition in grassland sites along temperature and precipitation gradients in southern Norway.
| Predictors | df | Estimates | F | P |
|---|---|---|---|---|
| Intercept | 43.45 | |||
| Temperature | 2 | 6.91 | 0.011 | |
| Sub-alpine | -4.99 | |||
| Boreal | 17.54 | |||
| Precipitation | 3 | 2.71 | 0.096 | |
| 2 | 4.05 | |||
| 3 | -5.44 | |||
| 4 | -19.55 | |||
| Temperature × Precipitation | 5 | 3.57 | 0.037 | |
| Sub-alpine × 2 | -7.75 | |||
| Boreal × 2 | -10.73 | |||
| Sub-alpine × 3 | 43.12 | |||
| Boreal × 3 | 5.56 | |||
| Sub-alpine × 4 | 29.94 |
Temperature and precipitation are expressed factorial variables (three temperature levels: alpine, sub-alpine, boreal, and four precipitation levels 1–4). Functional type (graminoid vs forb) and its interactions were not significant and therefore not included in the final model. n = 22.