Lowland heathland is a priority habitat for biodiversity in Europe. Working with the RSPB, Nature After Minerals encouraged the operator at Bryants Lane quarry to explore opportunities for heathland creation through the planning application process. Responding to a Review of Mineral Permission (ROMP) consultation, it was recommended that the operator integrate heathland restoration trial areas in the restoration scheme. This recommendation was subsequently picked up by the Mineral Planning Authority and written as a condition of the planning permission.
Potential best practice
Planning permission condition to trial creation techniques on former heathland soils to identify if lowland heathland restoration is feasible.
Bryants Lane quarry is located near the village of Heath and Reach, north of Leighton Buzzard in Bedfordshire. A ROMP for the site was brought forward by the quarry owner LB Silica Sand Ltd in 2014, and included details of the proposed restoration scheme.
Opportunities identified by RESTORE
Bryants Lane Quarry is at the western end of the Greensand Ridge, once an area of extensive heathland, almost all of which has been lost to historic development and agricultural improvement. The site has potential to demonstrate best practice in heathland restoration by trialling heathland creation in plots to establish heather and other typical vegetation on the substrate which had been deemed unsuitable by consultants (discussed in more detail on page 3); an area of the adjacent quarry at Sheepcote had been successfully restored to heathland.
The UK supports about 20% of the remaining lowland heathland in NW Europe with only 60,000 ha remaining in England (2014 figures). The restoration of heathland at Bryants Lane would contribute to England Biodiversity2020 Strategy aspiration to restore 7,500 ha of lowland heathland (Defra Terrestrial Biodiversity Group report 2013). This also accords with policy for the Greensand Ridge in the National Character Area (NCA) profile for The Bedfordshire Greensand Ridge (number 90), which states:
“Working to agree restoration plans and management agreements between landowners, operators and the Minerals Planning Authority for existing and former extraction and quarry sites that demonstrate geological, landscape, biodiversity and public access benefits.”
Why Bryants Lane Quarryfitted RESTORE objectives:
- Overlap between mineral site and landscape scale initiatives –Bryants Lane sits within the Greensand Ridge Nature Improvement Area (NIA).
- Proximity to existing Priority habitat – The RSPB’s Heathland Extent and Potential (HEaP) GIS map layer (figure 1) was used to check suitability. The HEaP map covers England and identifies heathland potential using several attributes, including soil type and previous heathland cover. The map shows that the quarry should support heathland and highlighted the degree to which the remaining patches of heathland are fragmented.
- Aggregated sites – Bryants Lane is part of a cluster of sand extraction sites at the western end of the Greensand Ridge, around Heath & Reach identified by the Greensand Trust’s Heath & Reach and Leighton-Linslade Sandpit Strategy (2011) as potentially suitable for the creation of lowland heathland.
- Operator – the site provided an opportunity to engage with LB Silica Sand Ltd (through Central Bedfordshire Council), an operator with which NAM and RESTORE had no previous involvement.
The original restoration proposal was to be to a conservation/amenity after-use of mixed deciduous woodland and grassland. This mosaic approach might be appropriate in parts of the site, as it reflects the patchwork of habitats on the Greensand Ridge. However, the ROMP application indicated uncertainty about whether the soils remaining on site would suit heathland due to the elevated pH and presence of clay.
It therefore proposed to treat subsoils with organic matter, nutrients and lime to improve them for a productive agricultural (eg sheep grazing) after-use. Fertilizer application and addition of lime would permanently exclude development of a species-rich vegetation typical of heathland and dry acid grassland habitat.
Our response and suggestions
Nature After Minerals and RSPB commented as follows:
“The presence of clay and a pH of 6-7 in the quarry substrate is not necessarily a barrier to heathland restoration and we would strongly encourage trialling heathland creation in selected areas. Providing the overburden and/or topsoil are low in nutrients - with low availability of phosphorus - replacing these in thin layers on the substrate (using sandier fractions if available) will help to create the requisite conditions for heathland development. A number of establishment techniques can then be considered, including transplanting heather turf and transferring litter and brash from a local donor site. Acidic conditions will continue to develop over time through the process of plant growth, decay and the build up of a litter layer. Heathland is a habitat with a slow growth dynamic and in the longer term, this process will allow the characteristic heathland podsol soil profile to develop."
Our response continued:
"At the very least, natural regeneration should be the prime restoration driver at Bryants Lane, as a grassland/scrub mosaic will form part of the wider landscape heathland mosaic at Sheepcote Quarry and Stockgrove Country Park."
"RSPB would be pleased to be involved in further discussions on the heathland potential at Bryants Lane and advising on the most appropriate establishment techniques for the site."
How this best practice is transferable
As the mineral planning authority, Central Bedfordshire Council was willing and able to adopt our recommendations for heathland trials in the planning permission. The Restoration, Landscaping and Aftercare condition (condition 30 of the permission) stated that:
“trialling of heathland plots by testing of overburden to determine pH levels and introduction of techniques for reducing pH levels; areas designated for placement of indigenous topsoils and soil placement depths to ensure optimal use of limited soil resource;..”
The results of the heathland establishment trials will help to further our knowledge of mineral restoration to heathland which could then be applied to other quarry sites on the Greensand Ridge, as well as dry sand and gravel quarry restorations elsewhere. If successful the trials will demonstrate that heathland creation is possible on substrates with slightly elevated pH, which will reduce in time with leaching and accumulation of heathland plant debris. A heathland soil profile may take many years to develop; this will need to be factored into the aftercare.
Central Bedfordshire Council also included a number of other good practice points in the condition to ensure a high standard of restoration and a net gain in biodiversity; retaining sandy exposed cliff face and other sandy habitat zones / features; incorporating localised variations within the approved contour profiles, and replacing of the existing non-native conifer (leylandii) screening along the boundaries of the site with new native hedgerow planting of the site.