Simple linear regression r2 values for the probability of roots at sidewalk joints within 1.8 m (6 ft) of tree as predicted by time since planting and trunk diameter.
| Genus | Adjusted r2 (dbh) | Adjusted r2 (time) | P-value dbh as a predictor of root problem | P-value time as a predictor or root problem |
|---|---|---|---|---|
| Gleditsia | 88.7% | 80.0% | <0.01 | 0.10* |
| Koelreuteria | 61.1% | 44.9% | <0.01 | 0.06* |
| Quercus | 30.2% | 38.1% | 0.03 | 0.02 |
| Zelkova | 49.6% | 54.1% | 0.02 | 0.06* |
| All trees | 75.5% | 62.1% | <0.01 | <0.01 |
↵*Denotes model that is not significant at the 95% level.