Curve model | Variable | R2 | p |
| x: altitude | 0.875 | <0.01 |
| x: gradient | 0.235 | <0.05 |
| x: aspect | 0.284 | <0.05 |
| x: altitude, | 0.788 | <0.01 |
| x: aspect | 0.558 | <0.05 |
| x: altitude | 0.686 | <0.01 |
| x: aspect | 0.342 | <0.05 |