Authors: Szabó, Ágota Réka; Ernst, Lunja M.;Gallé, Róbert;Batáry, Péter;

Degradation and disappearance of semi-natural habitats became a global conservation problem. Our study aims were to explore the complex processes that affect butterfly functional diversity and functional community composition in less productive and threatened grasslands. We examined the functional characteristics of butterfly communities with three contrasting design factors: habitat type (calcareous grassland vs. orchard meadow), management (managed vs. abandoned), and landscape context (forested vs. agricultural landscape). We surveyed butterflies of 20 calcareous grasslands and 20 orchard meadows in Central Germany. To test the effects of our design variables, we selected six functional traits (overwintering, voltinism, wing length, diet, flight period, territoriality) for each butterfly species, and we assigned values to them from the literature. Our results showed that habitat type had the strongest filtering effect on butterfly functional traits of the three design variables. Functional diversity indices, such as functional richness and divergence values, were higher in calcareous grasslands than in orchard meadows. We found that calcareous grasslands are characterised by butterflies having more specialist traits, which were moderated by the presence of management and landscape context. Therefore, to maintain the threatened butterfly fauna of calcareous grasslands, extensive management should focus on calcareous grasslands in forested landscapes.