PROJECT DESCRIPTION
BACKGROUND
One of the post-Cold War ‘peace dividends’ in Europe is the release of former military-industrial installations for other uses. The former ICI Nobel Explosives works at Penrhyndeudraeth, Gwynedd, North Wales, which started production in 1865, was a significant producer of explosives, partly for military uses. At its peak in the 1970's the plant employed 500 staff and produced 9000 tonnes of explosives annually. This sector of the industry is now concentrated in fewer sites, and the ICI site has been unoccupied for several years. The North Wales Wildlife Trust now owns the site, which is adjacent to areas of high amenity and environmental value, and aims to restore its environmental quality and open it to the general public. However, while the post-industrial land surfaces are no longer contaminated to toxic levels by industrial chemicals, the biological and physical condition of the substrate makes it difficult for the NWWT to develop semi-natural vegetation on the site.
OBJECTIVES
The project aimed to carry out the first stage of an environmental and ecological restoration of part of the former ICI site, covering 28ha in total. It aimed to demonstrate the application of restoration techniques to post-industrial land, using advanced planting methods and plant material of local genetic provenance, in order to increase the biodiversity and natural capacity by creating semi-natural habitats. Ultimately, it was intended that the site would be restored to a ‘heathland’ community NVC type H8 status.
RESULTS
Overall, the project has been a success, meeting almost all of its objectives and disseminating well within its rather specialised community. Firstly, the LIFE project aimed to use transferable and experimental methods for restoring heathland on waste areas. A technique was developed which involved collecting seed from under existing heathland on-site, propagating and growing the seed mixture in a greenhouse, and planting the heathland "plugs", using a crow bar, in holes in the rubble. Secondly, the project aimed to recover, manage and monitor semi-natural habitat and associated species in order to increase the biodiversity value of the site. Heathland Plug Experiments Experiments were carried out on the sieve size used to separate seed from the litter collected on site, and on the use of water retaining granules (Swelgel) at germination stage. The larger sieve size encouraged more birch (Betula pendula) germination, while the use of Swelgel had no noticeable effect. An experiment was then carried out on the effectiveness of different treatments of Swelgel and fertiliser on the planting of the heathland plugs on-site. During the UK outbreak of Foot & Mouth disease, staff had limited access to the site for 5 months, and trespassing sheep pulled heather plugs out. Fencing of the experimental areas was carried out immediately and access was permitted, leading to the abandonment of the first experiment, and a year-long extension to the project. A second similar experiment was set up, and monitoring showed little difference in the effectiveness of the treatments. More detailed analysis of heather vigour and the substrate was then carried out. After 35 months, the overall survival of the plugs was approximately 38%. The results showed that any variation in height of the heather plants was probably due to different physical conditions in the quadrat areas, apparently overriding the contribution made by fertiliser and Swelgel. There was a significant positive correlation between low height of growth and higher pH (0.01), and some evidence that this tied in with the locations of old buildings on the site. After 3 years it was concluded that this was an effective but labour-intensive method for establishing the basis of a heathland community on bare rubble. Longer term monitoring is required to assess how successful this technique is in creating a sustainable community. The costs may limit this technique to relatively small areas only. During the restoration, the site must be free from grazing, and the newly planted plugs require daily attention for the first few weeks, particularly watering. Management by strimming and pulling to reduce competition from natural colonisers such as Buddleia, bramble and birch was carried out throughout the experiment. Five years from the start of the experiment, the aim is to re-introduce grazing in order to maintain the heath community. There is evidence that a heather and gorse community is developing in the area of the second experiment (H8 - Calluna vulgaris/Ulex Europaeus National Vegetation Classification (NVC) & CORINE habitat code 31.2). Control plots within this area monitoring natural colonisation show that acid grassland would be developing here without the project (U4b NVC Festuca-Agrostis-Galium grassland, Holcus-Trifolium sub-community). Heathland is a threatened habitat throughout Europe, and this project is thus replacing a habitat which has been lost to many areas. Habitat restoration, management and monitoring Heathland plugs in excess to the experiment were used to create three areas of heathland on the rubble outside the experimental areas, which after 3 years showed a survival rate of 41% to 74%. The original project aim was to restore 5 areas on the site to woodland. In the end 3 areas were planted with willow whips of site provenance, showing a success rate of 40-55%. One site was re-designated for future buildings, and the other left to develop naturally. An area of grassland was maintained as a woodland glade by clearing bracken (Pteridium aquilinum) and scrub, and is of benefit to butterflies, dragonflies and feeding bats. The LIFE project contributed to the maintenance of some industrial buildings for wildlife and interpretation of the site to the public. They demonstrate the history of the site, while serving as roosts for bats and birds. They house equipment and an exhibition. Exterior interpretive panels were erected, and many guided walks and talks about the site have been given throughout the project. Leaflets, a video, and a mobile display have been produced showing the site's transformation, and good local and UK press coverage was achieved. Information about the project may be viewed on the web-sites www.wildlifetrust.org.uk/northwales and www.wildlifetrusts.org. Several conferences were contributed to, and dissemination will continue long after the end of the LIFE-funded project. European LIFE Environment, Heritage Lottery Fund, Countryside Council for Wales, and North Wales Wildlife Trust jointly funded the project. Technical assistance and greenhouse facilities were from the University of Wales, Bangor. Volunteers from the NWWT were crucial to the success of the project.
