Biodiversity

Context

Chapter 8 of Volume 2 of the PEIR sets out the preliminary assessment of the effects of the Proposed Development on biodiversity.

In addition to previously developed land, the Main Application Site comprises approximately 120ha of arable land, 26ha of managed grassland, 38ha of Wigmore Valley Park, plus areas of woodland, scrub, hedgerows, other pockets of grassland including calcareous grassland, and ponds. Off-site Car Parks comprise access roads, temporary buildings, areas of short perennial vegetation, grassland margins and areas of landscaping comprising scrub and trees.

The Main Application Site includes three sites locally designated for nature conservation, the Wigmore Park County Wildlife Site, Winch Hill Wood County Wildlife Site and Local Wildlife Site and Dairyborn Scarp District Wildlife Site. Winch Hill wood is also designated as ancient woodland.

Ecological surveys and desk based studies undertaken to date have demonstrated that the Main Application Site and the surrounding area is used by a number of protected or notable species, including badgers, bats, brown hares, hedgehogs, slow worms, common toads, common frogs, smooth newts, Roman snails, other invertebrates and a range of birds including barn owl and red kite.

Field surveys have identified populations of orchids at the Wigmore Park County Wildlife Site and other notable plants within the Main Application Site. Botanical surveys have confirmed the presence of wildlife habitats including ancient woodland, broadleaved semi-natural woodland, ancient and veteran trees, species-rich hedgerows, semi-improved neutral grassland and calcareous grassland. Various non-native invasive species have also been identified across the application site, including Japanese knotweed, Japanese rose, and cotoneaster species.

Mitigation measures

A range of measures to reduce effects on biodiversity are proposed as part of the Proposed Development. These include but are not limited to:

Construction

• best practice construction environmental management measures to minimise disturbance to habitats and species during construction, as described in the Draft CoCP;
• detailed mitigation strategies would be developed that outline species specific mitigation measures. Where badger setts or bat roosts would be lost or disturbed by the Proposed Development, a licence from Natural England would be sought, which may require the provision of replacement artificial badger setts and artificial bat roosts;
• where possible, the Proposed Development has been designed to avoid or reduce adverse effects on valued ecological features and deliver benefits for biodiversity in accordance with policy and best practice. Overall, the Proposed Development would deliver a minimum of 10% biodiversity net gain through the extensive landscaping and habitat creation proposals incorporated within the Proposed Development and the management of retained and proposed habitat areas;
• the landscape design includes large areas of habitat creation on and off site to partially mitigate the loss of habitats from construction and contribute to the project’s target of achieving a net gain in biodiversity. Much of the habitat creation would be provided within a large area of replacement open space that would be designed to mitigate for the loss of Wigmore Park County Wildlife Site and its habitats;
• existing vegetation, including woodland and hedgerow belts on the boundaries of the Main Application Site, would be retained wherever possible and a 15m buffer zone maintained around areas of ancient woodland and veteran trees to avoid damage to roots;
• orchids would be moved from the Wigmore Park County Wildlife Site to new sites within the large area of replacement open space and habitat creation and protected from recreational pressure;
• new habitat features would be provided in the form of deadwood in open areas for insects, and artificial bat roosting and bird nesting boxes on buildings and retained trees;
• habitat creation measures for barn owl and red kite would be provided at a safe distance from the airport, to avoid increasing the risk of bird strike. Such measures would include the creation of grassland, hedgerows and woodland. Opportunities would also be sought to provide barn owl nesting boxes within the wider landscape at a safe distance from the Proposed Development, and to provide alternative barn owl nesting opportunities to those lost to construction; and
• in addition to the mitigation measures detailed above, potential enhancement measures are also being explored, such as enhancement of species-poor/defunct hedgerows and woodland creation to improve connectivity with the wider landscape.

Operation

• a Draft Landscape and Biodiversity Management Plan (see Appendix 8.2 in Volume 3 of the PEIR) has been developed to set out requirements for establishing, managing and monitoring areas of habitat created;
• the Proposed Development would use directional lighting to avoid light spill onto retained and adjacent habitats to minimise disturbance of nocturnal species, such as bats and badgers; and
• opportunities will be sought to implement sensitive management of retained veteran trees within the wider landscape, this may include measures such as thinning of young trees around veteran trees to reduce stresses upon the tree. Opportunities will also be explored to undertake ‘veteranisation’ of mature trees within the Applicant’s ownership.

Likely significant effects

Construction

The Proposed Development would result in direct physical effects on biodiversity due to construction on currently undeveloped land and indirect effects due to disturbance during construction. For instance, the construction of the Proposed Development would result in the direct loss of 15.38ha, which is almost 100% of Wigmore Park County Wildlife Site, and in the loss of approximately 2.18ha (29%) of the Dairyborn Scarp District Wildlife Site. Winch Hill Wood County Wildlife Site, Local Wildlife Site and ancient woodland would be retained, with the exception of minor tree removal on the perimeter of the site for arboriculture reasons only. These sites would also be subject to indirect effects as a result of construction disturbance.

With substantial habitat replacement provided by the Proposed Development, resulting in a minimum of 10% biodiversity net gain, and mitigation in place, as described above, these effects are not likely to be significant after habitats provided have matured.

Operation

Disturbance from the operation of the Proposed Development may displace protected species from using habitats adjacent to the airport. In addition, effects may occur due to changes to the quantity and direction of surface water run-off. However, with mitigation in place, as described above, these effects are not likely to be significant.

The air quality assessment of ecological sites found a temporary significant effect on Winch Hill Wood, as a result of nitrogen deposition and the resulting effect on species richness. However, with the management of the woodland to improve its condition, as set out within the Draft Landscape and Biodiversity Management Plan, this effect would reduce to not significant in the long term.

Furthermore, the provision of habitats as part of the landscaping proposals is considered to provide a long-term benefits due to the net increase of habitats.

Completing the assessment

To complete the assessment, the ecological baseline will continue to be reviewed and updated, with further ecological surveys to be completed to supplement the baseline information, where required.

Further assessment of air quality effects from the Proposed Development upon designated nature conservation sites that are sensitive to changes in air pollution will be undertaken.

Documents

PEIR Chapter 8 : Click Here

Figures

8.1 Ecological Statutory : Click Here
8.2 Ecological Non-Statutory : Click Here
8.3 Ecological Constraints Plan : Click Here

Appendices

8.1 Ecology Baseline Report : Click Here
8.2 Draft Landscape and Biodiversity Management Plan : Click Here
8.3 Habitats Regulations Assessment No Significant Effects Report : Click Here
8.4 Draft Bird Strike Risk Assessment : Click Here