Construction of verges to benefit biodiversity

Background

Transport infrastructure has negative impacts on the environment and landscape. However, right-of-way areas of roads and railways can be adapted to support biodiversity by offering habitats for species and contributing to green infrastructure in the landscape.

The Swedish Transport Administration has since long been working to strengthen the ecological quality of road verges and railway areas in construction and maintenance. This is done both through practical work and in internal guidelines. However, the knowledge needs to be strengthened regarding the best location and design of new habitats in connection with the construction of new roads and railways, and regarding which are the most cost-effective methods to benefit biodiversity.

Activities

This project aims to develop the knowledge for better and more tangible guidelines for how the construction of transport infrastructure can create side areas with the best possible value for biodiversity.

Methods and basis for guidelines are developed in the project regarding:

• Factors (soil, structure, vegetation, management etc.) that are important for biological diversity in different habitats in side areas.
• Assessment of which type of habitat that may be most suitable to create in a certain landscape. The match between the new biotope and biotopes in the surrounding landscape determines to what degree side areas can support biodiversity in the landscape.
• How vegetation for biodiversity can be established, for example through spontaneous colonization of species, re-use of topsoil with seed bank, seeding/planting etc.
• Choice of plant material including provenance.
• Measures for preserving biodiversity when reconstructing existing roads where the side areas in themselves have high nature values.

The knowledge is mainly developed through collaboration with and learning from the Swedish Transport Administration’s ongoing construction projects and other activities.