How frequent is metapopulation structure among butterflies in grasslands? Occurrence patterns in a forest-dominated landscape in southern Sweden
We determined the proportion of butterfly species that occur as metapopulations with grasslands as the only habitat. We counted all butterflies in 19 semi-natural grassland patches in a forest-dominated landscape in southern Sweden over a 5-y period. Seven of the 44 butterfly species observed exhibited a metapopulation structure. The other species either use grassland mainly for adult feeding but