Spatial arrangement of woody habitats and the distribution of birds and butterflies in agricultural landscapes in the Netherlands

In this study we analysed the relationship between the spatial arrangement of woody habitat and the presence of bird and butterfly species in agricultural landscapes in the Netherlands. The occupation probabilities of 32 bird species and 8 butterfly species in km-grids were analysed with logistic regression analysis. First parameters describing the internal quality of the km-grids and next parameters describing the spatial arrangement within and outside the km-grids were added to the regression model. The regression analysis showed the importance of the spatial arrangement both within and outside the km-grids. We found a significant effect of the internal spatial arrangement for 27 bird species and of the external arrangement for 26 bird species. We found for 6 butterfly species an effect of the external spatial arrangement on the occupation probabilities. The effect of the landscape within 2 km had a stronger effect on the butterflies than the landscape within 5 km around the km-grids. The results show that measures to increase biodiversity in agricultural landscapes should not only take the amount and quality of habitat into account, but also with the spatial arrangement of the habitat, both at small (1 km(2)) and larger scales (several km(2)).