Talk Motorway edges as refugee for butterflies – preliminary results of case study from the Czech Republic

Motorways and other roads are usually considered as threat for most of the nature. They make barriers for migratory species, fragmented homogenous habitats, cause roadkills etc. There is also another point of view on roads. Mainly in Western Europe and United States there is a pressure to use the edges of roads (and also railways and river dikes) as a habitat source for different invertebrates, mainly for butterflies. The usual way of management on these habitats is planting of bushes and on some places mowing of grass turf. This turf is composed mainly from different grass species, herb are generally sparse. Our aim is to use motorways as a migratory corridor for different thermophilous butterfly species and as a connection between particular Protected Areas across whole Czech Republic. In year 2015 we established 10 sites across the country where we placed 10 Moericke traps per site in 100 m long transect for collecting of butterflies to state initial stadium of local butterfly community. Traps were emptied 6 times during season (altogether 600 samples per season). We collected 27 species (363 specimens). Amon common ubiquitous species we found also some rare and endangered species (Polyommatus bellargus, P. thersites, Coenonympha arcania, Brinthesia circe, Colias alfacariensis) or typically xerophilous common species (Plebejus spp., Zygaena loti). Most these butterflies prefer as a food plant different species of family Fabacae or grasses. But all need special structure, they cannot survive in dense turf which is usually present on our localities. On the other hand localities have potential to host interesting butterfly species and possibly they could be used as stepping stone for future migrations. At year 2015 we start with future management of sites – we sowed half of all sites by seeds of hemiparasitic plant Rhinanthus alectorolophus to control grass population and bring space for herbal species into the turf.  The whole study will continue until the year 2019, when we will observe the impact of population of R. alectorolophus on vegetation composition and via this way also on butterflies populations (via food plants). We expect, that due the decreasing mass of grass species, herbal species will expanse to the space within the turf and these plants will host butterflies. We suggest that reduction of grass will lead to decreasing management cost of motorway edges thanks to lower vegetation productivity.

motorway edges, biodiveristy, butterflies, hemiparasitic plants, new technology