Table 1 Response variable analysed and habitat quality measures at metapopulation, landscape and microhabitat scale incorporated in the analysis. Moreover, the generated spatial predictors based on a third-degree polynomial of the geographic coordinates (spatial), are shown. Applied transformations are specified.
Scale | Environmental Factor | Variables | Transformation |
|---|---|---|---|
Response | Intensity of space use by Dupont’s lark in 2015 | Kernel Density Function (KDF) | \(\sqrt{x}\) |
Metapopulation | Connectivity | Relative connectivity RC (distance to the nearest occupied population) (km) | None |
Patch size | Surface of optimal habitat (i.e. shrub-steppe with slope lower than 15%) (ha) | log(x) | |
Landscape | Proximity to sources of anthropogenic pressure | Distance to the nearest crop (km) | log(x) |
Distance to the nearest wind turbine (km) | None | ||
Land-use types | Shrub-steppe with slope <15% (%), Shrub-steppe with slope > 15% (%), Pastures (%), Crops (%), Ploughings (%), Afforestations (%), Infrastructures (%) | \(arcos\,(\frac{x+1}{100})\) | |
Microhabitat | Food availability (biomass) | Coleoptera (mg), Blattodea (mg) and Hymenoptera family Formicidae (mg) | log(x + 1) |
Orthoptera (mg) and Coprophagous arhtropods (mg) | \(\sqrt{x}\) | ||
Diptera (mg) and Araneae (mg) | None | ||
Herbivore abundance | Dung counts | \(\sqrt{x}\) | |
Horizontal plant structure | Total vegetation cover (%) and Shrub cover (%) | \(arcos\,(\frac{x+1}{100})\) | |
Bare ground cover (%), Rock cover (%), Lichen cover (%), Moss cover (%), Detritus cover (%), Perennial herbaceous cover (%) and Annual herbaceous cover (%) | ln(x) | ||
Vertical plant structure | Maximum modal height (cm) and Number of contacts at 0–5 cm, 5–10 cm, 10–30 cm and above 30 cm height | \(\sqrt{x}\) | |
Floristic composition | Individual cover of perennial species (both woody and herbaceous) (%) | None | |
Spatial | Geographic coordinates | Third-degree polynomial: X, Y, XY, X2, Y2, X2Y, XY2, X3, Y3 | None |
