Authors: Öckinger, Erik; Dániel-Ferreira, Juliana;Fourcade, Yoan;Bommarco, Riccardo;Wissman, Jörgen;

Grassland habitats along linear infrastructure, such as road verges and power-line corridors, cover vast areas and constitute an opportunity for conservation of species associated with declining semi-natural grasslands. It is however unclear to what extent infrastructure grasslands harbour these species. We surveyed plant, butterfly and bumblebee communities in semi-natural pastures of high nature value, road verges and power-line corridors in 32 landscapes in Sweden. We compared alpha and beta diversity among these habitats, and tested how their area in the landscape contributed to alpha, beta and gamma diversity. The alpha diversity of all three species groups was as high in power-line corridors and verges of small roads as in semi-natural pastures, regardless of landscape composition. Although there were large similarities in the community composition among habitats, there were important differences between infrastructure habitats and semi-natural pastures. Landscapes with power-line corridors had higher plant alpha and gamma diversity than other landscapes, but there was no such effect for butterflies or bumblebees. Novel grasslands along infrastructure cannot replace semi-natural grasslands as habitat for the most specialized grassland plants and insects, but especially in landscapes with low area of semi-natural grasslands they can be important habitats and should be managed to promote biodiversity.