Table 1. Best mixed models for ecological effects on stomatal density (SD) and stomatal length (SL) at the species and community levels.
| Factor | Species level |
Community level |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Log SDL |
Log SLL |
Log SLC |
Log SDC |
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| df | F | Variance explained (%) | df | F | Variance explained (%) | df | F | Variance explained (%) | df | F | Variance explained (%) | |
| PFT | 4 | 2.85 | 15.3* | 4 | 56.70 | 22.8** | |
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| Environmental variables | ||||||||||||
| MAT | 1 | 0.51 | 5.2 | 1 | 10.15 | 5.4* | 1 | 8.16 | 36.7* | 1 | 6.12 | 35.2* |
| Soil N | 1 | 0.12 | 4.7 | |
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| Interaction terms | ||||||||||||
| PFT × MAT | 4 | 2.89 | 16.6* | |
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| PFT × Soil N | 4 | 2.62 | 17.9* | |||||||||
| MAP × Soil N | 1 | 2.14 | <0.001 | |||||||||
| Random factor | ||||||||||||
| Site | 8 | 0.46 | 0.3 | 8 | 0.19 | 0.2 | 8 | 7.99 | 30.9* | 8 | 9.57 | 45.9** |
| Residuals | 880 | 40.0 | 856 | 71.6 | 22 | 32.4 | 22 | 18.9 | ||||
PFT, plant functional type; MAT, mean annual temperature; MAP, mean annual precipitation. df, degrees of freedom. Model with the lower Akaike information criterion (AIC) value was chosen as the final model (see Supplementary Table S5). *P < 0.05; **P < 0.01.