BayCEER Workshop 2008

Impact of local and surrounding landscape predictors on butterfly diversity in calcareous grasslands

Habitat area and habitat quality have strong impacts on butterfly species diversity. However it is less well known how the surrounding landscape affects species occurences in fragmented habitats. The aim of this study is to investigate the impact of landscapes differing in the amount of grasslands and potential dispersal barriers on butterfly species richness. We conducted eight butterfly surveys from April to August 2007 in 62 paired small and large grassland patches within 31 independent landscapes. In total we identified 88 butterfly species, including burnets.
We expect to show that butterfly diversity is high in large habitats, in landscapes with a higher proportion of calcareous grasslands, and in landscapes with less dispersal barriers. Furthermore we expect management to play a crucial role in determining factors of habitat quality, e.g. flower cover and bush cover. In general we expect stronger effects on habitat specialists than on more generalized species.