Brownfield Robert Brook (Alamy)
URBAN Derelict, disused and unloved, many brownfield sites are viewed as ripe for development, but these abandoned areas <strong>of</strong>ten provide a much-needed refuge for important wildlife. Great crested newts, slow worms, common lizards and black redstarts all make their home in the mosaic <strong>of</strong> different habitats found there. Around 15% <strong>of</strong> nationally rare and scarce invertebrates have been found on brownfield sites, including 50% <strong>of</strong> rare solitary bees and wasps, and 35% <strong>of</strong> rare carabid beetles 15 , and some are found nowhere else in the UK 16 . Brownfield sites can also support a range <strong>of</strong> important flowering plants, mosses and lichens – <strong>of</strong>ten including species that are declining in the wider countryside, such as the exquisite bee orchid. Studies in the Midlands suggest that the best brownfield sites even match ancient woodlands in terms <strong>of</strong> the number <strong>of</strong> species, especially rare ones, found there 17,18,19 . The value <strong>of</strong> brownfield sites Brownfield sites tend to have nutrient-poor soil, which prevents dominating plant species from taking hold. As a result, nectar-rich flowers flourish, providing hoverflies, bees and butterflies with nectar and pollen. Patches <strong>of</strong> open ground heat up in the sun, providing perfect basking conditions for reptiles, while burrowing and ground-nesting invertebrates make the most <strong>of</strong> the bare soil. The diverse mosaic <strong>of</strong> different habitats, all found within a relatively small area <strong>of</strong> brownfield land, are essential for many invertebrates as they have different habitat requirements at different life stages. Case study: A powerhouse for nature Case study: Back from the brink Small ranunculus moth Brownfield habitat has been extremely important for the spread <strong>of</strong> some formerly rare species, such as the small ranunculus moth. This species had disappeared from Britain by the early 20th century, but has now recolonised an area <strong>of</strong> North Kent and spread as far north as Yorkshire. As the countryside becomes steadily more degraded for wildlife, due to agricultural improvement and development, brownfield sites are becoming increasingly important. They provide refuges for wildlife, and link areas <strong>of</strong> more traditional habitat. However, although individual brownfield sites can support an incredible diversity <strong>of</strong> plants and animals, key populations at small, isolated sites can be vulnerable to extinction – that’s why the overall network <strong>of</strong> brownfield areas, which allow wildlife to move around the landscape, is so important. Saving brownfield nature Although greenfield land can be less valuable for wildlife, it is <strong>of</strong>ten passed over for development in favour <strong>of</strong> brownfield sites. Since 2008, around 50% <strong>of</strong> high wildlife value brownfield land in the Thames Gateway has been lost 20 . Neil Bowman (FLPA) Will George (<strong>RSPB</strong>) Brown-banded carder bee Brownfields lack statutory protection; there are only two SSSIs designated for their brownfield invertebrates in the UK. Although organisations such as Buglife and the Wildlife Trusts have carried out research and campaigned to protect biodiversity-rich brownfield sites, we still have a long way to go. An old power station might not be the first thing that springs to mind when you think <strong>of</strong> places to see rare wildlife, but it has been suggested that West Thurrock Marsh in Essex is one <strong>of</strong> the most important sites for biodiversity in the UK, with over 1,400 species recorded so far, including many rare species 17,18,19 . Unfortunately, its many invertebrates, such as the brown-banded carder bee and distinguished jumping spider, are threatened by the partial development <strong>of</strong> the site. The best brownfield sites match ancient woodlands in terms <strong>of</strong> the number <strong>of</strong> species, especially rare ones, that are found there. STATE OF NATURE 2013 59