Effect of climate,topography and habitat on species-richness of breeding birds in Poland

We developed predictive maps of farmland and forest species richness which are based on the “focal species concept” and remote sensing data. We explored environmental preferences of 17 farmland and 33 forest species in Poland, using data from the Pan-European Monitoring Scheme. The largest number of farmland species was noted in the central and eastern parts, while the opposite trend was observed in the case of forest species, where the preferred areas were in the north and south-east. The most important environmental component affecting the bird faunas of farmland and forest was a gradient from arable fields to forest. This relationship is unimodal, which means that on a meso-geographical scale the highest species richness occurred in heterogeneous landscapes where fields are interspersed with forest. Our results also indicate that the geographical gradient in Poland's bird fauna can simply be attributed to the habitat-based distinction: western and central parts are dominated by large agricultural habitats and coniferous forest, while in other areas predominate mixed forests and extensively used farmland. Among the climatic factors, only rainfall influenced the farmland bird species. Its effect is non-linear, but positive, which means that in areas with higher rainfall more species are recorded.Our predictive maps are complementary to research on population trends, and can be an essential tool for effective management and conservation of species populations on a trans-national scale.