Table 1.
Backwards selection results for IBR models optimized using ResistanceGA. All feature layers were analysed with the natural log of geographical distance as a covariable in MRM to correct for IBD. Most features acted as conduits for dispersal (feature resistance = 1) and had lower resistance values for the surrounding landscape (matrix resistance), while agriculture had a high feature resistance, indicating that it acted as a dispersal barrier. Significant features in italics.
| landscape feature | feature resistance | matrix resistance | initial model |
final model |
||||
|---|---|---|---|---|---|---|---|---|
| coefficient | probability | VIF | coefficient | probability | VIF | |||
| geographical distance | n.a. | n.a. | −0.058 | 0.030 | 4.77 | −0.035 | 0.075 | 2.376 |
| rivers | 1 | 72.05 | 3.65 × 10−5 | 0.019 | 4.97 | 3.88 × 10−05 | <0.001 | 2.376 |
| development (high) | 1 | 97.40 | 1.63 × 10−5 | 0.067 | 11.90 | — | — | — |
| roads | 1 | 48.73 | −8.87 × 10−6 | 0.195 | 2.44 | — | — | — |
| agriculture | 271.15 | 1 | −1.32 × 10−5 | 0.185 | 6.40 | — | — | — |
| development (low) | 1 | 57.48 | −1.38 × 10−7 | 0.972 | 6.88 | — | — | — |
| canopy covera | n.a. | n.a. | −5.90 × 10−8 | 0.987 | 5.49 | — | — | — |
aCanopy cover was a continuous surface with an inverse Ricker relationship to optimize resistance cell values (see electronic supplementary material, figure S2).