The Living Highways Project
The Living Highways Project is an on going collaboration between The University of Sheffield, The Sheffield and Rotherham Wildlife Trust and Amey, a public services company contracted by Sheffield City Council to manage road verges for a 25 year period from August 2012. The aim of the partnership is to find out if biodiversity and ecosystem services (benefits provided to humans by nature) can be enhanced on road verge sites whilst reducing maintenance costs.
Roadside verges are an important but often ignored aspect of urban greenspace. In sheffield roadside verges managed by Amey have an area of ~290 ha, along ~2,000 km of roads. Most road verges consist of regularly mown grassy verges, for practical reasons such as to provide drivers with sight lines at intersections, provide street parking, allow space for road signs and because it tends not to provoke negative reactions from residents. However, despite being highly disturbed and often polluted, verges have the potential to support a considerable plant and animal diversity. They can also play an important role in providing ecosystem services such as improved air quality, noise reduction, carbon storage, storm-water management, local climate regulation, pollinator support, aesthetic and psychological benefits. Hence, there is substantial scope to enhance these benefits by altering verge management.
A review of the state of the art in road verge management has already been produced, which assesses the alternative approaches to current management practices, the evidence for enhancing both biodiversity and a range of services, and how cost effective these approaches might be. It found that decreased mowing frequencies and removal of grass cuttings can enhance biodiversity and ecosystem service provision. Construction of wildflower meadows are particularly beneficial for floral and pollinator biodiversity and cultural/aesthetic services. Rather more major changes such as additional tree planting and establishment of short-rotation coppice plantations can enhance some components of biodiversity and deliver a wide range of ecosystem services. There is even potential to use less polluted verges for food production.
Road verge pollution can be an issue, and another study just being completed has focused on ultimately understanding the extent to which soil pollution and compaction might affect vegetation choices and management approaches. Specifically the study has explored how heavy metal and salt concentrations, levels of nitrogen and phosphorus and compaction vary across verge sites in Sheffield that differ in traffic density and gritting priority.
The collaborators are now moving on to test management options on the ground at experimental road verge sites. An ACCE PhD student from Animal and Plant Sciences started in October 2015, aiming to find out the extent to which altered mowing frequencies and wildflower planting can enhance biodiversity and ecosystem services, public perceptions of road verges, how cost effective management approaches are, and how these green spaces can act as habitat corridors and provide connectivity.