Table 2. Landscape variables.
| Landscape variables | Unit | Description |
|---|---|---|
| Perimeter–Area Fractal Dimension (PAFRAC) | None | PAFRAC reflects the shape complexity across a range of spatial scales (patch sizes). It equals two divided by the slope of the regression line between the logarithm of patch area (m2) and the logarithm of patch perimeter (m). |
| Splitting Index (SPLIT) | None | SPLIT is the number of patches with a constant patch size when the landscape is subdivided into S (value of the splitting index) patches. It equals total landscape area (m2) divided by the sum of the patch area (m2), summed across all patches. |
| Patch Richness Density (PRD) | Number per 100 hectares | PRD equals the number of different patch types within the landscape divided by the total landscape area (m2). |
| Total Edge (TE) | Meters | TE equals the sum of the lengths (m) of all edge segments in the landscape. |
| Total Class Area (*) (AREA) | Hectares | AREA equals the sum of the areas (m2) of all patches of the corresponding patch type, divided by 10,000 (to convert to hectares). |
| Edge Density (*) (EDGE) | Meters per hectares | EDGE equals the sum of the lengths (m) of all edge segments involving the corresponding patch type, divided by the total landscape area (m2), and multiplied by 10,000 (to convert to hectares). |
Variables were extracted using FRAGSTATS in a 200-m radius buffer around each trap. Landscape metrics marked with an asterisk were computed separately for each individual land cover class. Remaining metrics were computed with all land cover classes together.