Talk A management model for maintenance of roadsides with high biodiversity values along public roads in Sweden

The Swedish Transport Administration has since the mid-1990s run a project focusing on identifying and assessing road verges with particularly high habitat and species richness. During recent years the survey efforts have increased, which has resulted in a greater understanding of the ecological importance of infrastructure. For some areas the public road network has been more thoroughly surveyed regarding the presence and abundance of vascular plants and insects. About 2-5% of the public road network system in southern and central parts of Sweden is considered to present higher levels of species richness and habitat value. The Administration is responsible for the management of all state-owned roads in Sweden. This road system consists of a wide range of road types in terms of size, construction type and traffic volume; from narrow gravel roads with very little traffic to multilane highways. The administration itself has no operational capacity, which means that all road work is procured on the market from contractors. Road verges that have been found to display higher levels of species richness and habitat value are designated as “species rich roadsides”. The maintenance of these stretches is regulated in a system of around 110 maintenance contracts across the country, with each contract being for a term of 4-6 years. These contracts are in turn governed by a steering document (Standard Description of Road Management) specifying which types of works are included in the contracts. The steering document allows road verges designated as “species rich roadsides” to be mowed later in the year relative to ordinary roadsides. At present, four different types of maintenance regimes are in operation for species rich roadsides: 1) late mowing, 2) extra late mowing, 3) late mowing with removal of plant debris and 4) site specific management plans. The general aim of the existing model is to allow plants to complete their flowering season and to provide floral resources for different kinds of pollinating insects. In the surrounding agricultural landscape, certain habitats and species are in continual decline, which makes it even more imperative to conserve the infrastructural habitats. Some of the sites subject to specific management plans provide habitats for endangered species, requiring even more elaborate management efforts. Even though the system does not work perfectly due to a lack of suitable equipment, failure to communicate and provide correct information to the subcontractors, and the impacts of different types of other road management activities – it has given us an opportunity to initiate a process towards more adapted, ecological maintenance of roadsides. The aim going forward is to regularly evaluate the species rich roadsides with respect to their ecological status. This will give a basis for deciding whether the current level of management is sufficient for attaining a favourable conservation status for the designated habitats and species. Maintenance of species rich roadsides is indisputably a field in which harsh infrastructure realities clash with ecological theory and practice.

Verge management, road maintenance, infrastructure habitats; biodiversity