Keyn Glas - Green Ribs

The Green Ribs are green infrastructure corridors following valleys, which emanate like ribs from the spine of the A30 along the ridge through central Cornwall.

The project was funded under Highways England's Environmental Designated Funds programme. It was devised to go beyond standard mitigation design to address the wider negative effects of the A30 on biodiversity and the landscape.

The project aims to enhance habitats for wildlife and to improve the character and productivity of the central Cornish countryside. This is achieved through designing and implementing landscape interventions to improve the quality, condition, extent, and connectivity of habitats and landscape features. The project objectives are:
- To conserve, enhance and reinforce existing habitats;
- To create new habitats and provide habitat links connecting existing habitats;
- To reinstate historic landscape features; and
- To make the landscape more resilient to climate change.

At the start, the team surveyed the landscape and used Condatis, a newly developed habitat connectivity analysis tool, to analyse wildlife movement and habitat distribution. This enabled us to target areas where interventions would have the greatest impact on biodiversity.

The team designed a suite of nearly thirty bespoke and locally distinctive landscape interventions, such as woodlands, grasslands, field boundaries, ponds and orchards. These provide benefits to biodiversity, the character of the landscape and to local farms and communities. Collectively these interventions work together creating a multiplier effect, providing an overall impact greater than the sum of its parts.

So far, phase 1 has delivered interventions across 9 farms and connected 32 habitat areas. We have planted 13,000 new trees, created and restored five traditional orchards and restored four pond habitats. Eight woodlands are under enhanced management and we've put in eight kilometres of new and enhanced field boundaries, including traditional Cornish hedges, hedgerows and fencing.

This will result in significant increases in habitats, providing 97% to 242% net gains in biodiversity measured using the government's Biodiversity Net Gain Calculator. The interventions built in phase 1 will absorb around 10 tonnes of Co2 every year and will contribute positively towards climate change resilience, and help achieve six of the United Nation's thirteen Sustainable Development Goals

The project was governed by a multi-partner project steering group. Led by Highways England, the steering group included Cornwall Council, Cornwall Wildlife Trust, Cornwall Catchment Partnership, the Environment Agency, Natural England, and Historic England.

The project was designed by a team of landscape architects, ecologists, heritage consultants, water scientists. It was delivered through successful engagement with multiple stakeholders, including many private landholders. The interventions are delivered on land owned by multiple private landowners whose ongoing support is crucial to ensure long-term success of the project.

Green Ribs is unique in its scale and nature. The strategy is ambitious, holistic and broad in scale, yet it remains workable. Within two years it has delivered landscape-scale green infrastructure enhancements on third party land. It provides an exemplar for future projects developed under Highways England's Environmental Designated Funds programme.