Table 4 Poisson regression with understory diversity (species richness) as the dependent variable and environmental variables included as independent variables. n = 39, p value ≤.05 level of significance
| Variables | B | Wald χ 2 | p value |
|---|---|---|---|
| Canopy density | −1.033 | 50.267 | <.000 |
| Horizontal heterogeneity of canopy surface height | 0.188 | 38.785 | <.000 |
| Slope gradient | −0.404 | 1.568 | .211 |
| Distance from a road | 0.001 | 8.302 | .004 |