Project Background
Smith Jenkins on behalf of Welcome Break sought permission to extend the lorry park at Corley Motorway Services. Ecology by Design was commissioned by Welcome Break in February 2017 to carry out necessary ecological surveys on the site.
Survey Background
Planning permission was required to construct the lorry park extension. Ecological surveys were required as part of the planning permission and therefore a preliminary ecological appraisal was recommended. The site was within Warwickshire which is one of the counties which now require biodiversity calculations to assess the impact of the proposal. Warwickshire County Council Ecological Services recommended that a Biodiversity Impact Assessment calculation was completed to accompanying the planning application. The aim of the Biodiversity Impact Assessment was to assess the biodiversity impacts and where necessary provide compensation for biodiversity loss under planning policy through onsite mitigation or biodiversity offsetting.
Survey Method
A preliminary ecological appraisal was carried out on the site. The habitats identified on site included improved grassland with boundary dense scrub. Mixed semi-natural woodland bounded the north of the site which separated the site with the service entry road. A ditch with scattered broadleaved trees bounded the south of the site. The site was previously grazed by horses and therefore the vegetation was kept at a managed level. The site proposal was designed in a sensitive manor to avoid the boundary ditch, however the lighting design for the lorry park included light spill on adjacent trees which had been highlighted as having potential to support roosting bats.
Following the mitigation hierarchy, avoidance was considered as the first option, however due to the nature of the project lighting was necessary and therefore we had to mitigate accordingly.
The tree in question was a semi-mature oak (Quercus robur). A preliminary ground level roost assessment was carried out on the tree and assessed it as having bat potential due to the large lighting strike crack down the trunk and multiple cavities. The large extent of the features meant that a preliminary roost feature inspection survey utilising tree climbers or a cherry picker was not appropriate as there was a high risk of an inconclusive result and therefore full emergence and re-entry surveys were carried out on the tree.
Outcome
No bats were recorded emerging or re-entering the oak tree and therefore no further mitigation was required for bats. However, to ensure the site was enhanced for bats, bat boxes were recommended to be put on boundary trees to provide roosting opportunities. The landscape plans included enhanced boundary features with new hedgerows and a pond to provide and strengthen green corridors on site. This was particularly important as it would allow the continued foraging and commuting by bats along the sites boundaries. Furthermore, new planting would include a wide variety of native plants of local provenance. To further add value to the site it was recommended that cut vegetation was used to create small, stacked piles of wood along the sites boundary which would provide refuge for reptiles and amphibians. Bird nest boxes were also recommended on boundary trees.
The biodiversity calculations showed a net loss of biodiversity due to the change of a grassland field to a hard-standing lorry park. Even with the additions of hedgerow planting and a pond there was still an overall loss to the biodiversity on site. The proposal was modified to include a larger area of improved grassland to be enhanced with wildflower planting. The inclusion of further onsite mitigation provided efficient compensation for the overall change of use of the site.