Brownfields -Building plots or Biodiversity hotspots?

 Photo (c) Greg Hitchcock

Land covered in pulverised fuel ash from a coal power station at West Thurrock, Essex. Polluted wasteland or wildlife haven? Photo (c) Greg Hitchcock

This week I made my TV debut on none other than BBC’s the One Show. I was one of a team of keen ecologists tasked with finding a suite of rare invertebrates in ‘Britain’s rainforest’, Canvey Wick SSSI. It was on the day of filming in early summer that I caught my first Shrill carder bee Bombus sylvarum, one of the UK’s rarest bumblebees, and handed her to entomologist and presenter Dr George McGavin.

This rich nature reserve in Essex is deserving of the prime time TV spot. It supports over 1,400 species of invertebrate including 30 Red Data Book species and 3 previously thought extinct in the UK! Perhaps surprising then that this site was previously developed for an oil refinery and has been a dumping ground for dredged silt from the Thames. In other words, it is a Brownfield site.

The rare and distinctive Shrill carder bumblebee (Bombus sylvarum)  is restricted to just a few areas in the UK. Thames gateway brownfields are one of its strongholds, providing the richness of wildflowers it needs from spring to autumn, especially legumes such as vetches with thrive in disturbed areas. Photo (c) Ivar Leidus.

The rare and distinctive Shrill carder bumblebee (Bombus sylvarum) is restricted to just a few areas in the UK. Thames Gateway brownfields are one of its strongholds, providing the richness of wildflowers it needs from spring to autumn, especially legumes such as vetches which thrive in disturbed areas. Photo (c) Ivar Leidus.

Brownfield is a term given to land with a past use for industrial or commercial purposes, sites that have been developed or otherwise heavily modified by people but are now abandoned. It is, by definition an artificial habitat and opinions of it are greatly divided, but for some wildlife it is a lifeline in our modern landscape.

To conservationists, they are grossly undervalued. Invertebrates residing in Thames Gateway brownfields alone include over 100 Red Data Book species, over 400 Nationally Scarce species, at least one in seven UK fly species and a remarkable 74% of the national fauna of bees and wasps. Good brownfield sites can also offer important refuges for most of Britain’s native amphibians and reptiles, Bats, Dormice, Hares and Water voles as well as birds including the specialist Black Redstart and otherwise declining farmland birds such as Skylark, Barn owl and Turtle dove, not to mention rare flora and lichens.


A few weeks after the filming, I was on another mission on a different Thames-side brownfield. Rifling through the rubble and rubbish, my colleagues and I looked like the cast of CSI in our respirator masks and full body overalls to protect us from asbestos contamination, but we were searching for precious gems. As I lifted another brick, there one was, a flash of electric blue and bright orange-the rare and beautiful Streaked bombardier beetle (Brachinus sclopeta), a London brownfield speciality.

Streaked bombadier beetle. In the UK, this living gem is unique to London brownfields.  Photo (c) Oldbilluk.

                                                                                                        Streaked bombadier beetle (Brachinus sclopeta). In the UK, this living gem is unique to London brownfields. It relies on the area’s earth mounds, rubble and profusion of arable plants which provide food for the larvae’s seed-eating Ground beetle hosts. Its adult lifestyle is still largely unknown.               Photo (c) Oldbilluk.

This beetle was one of the lucky ones.  It was part of a rescue mission aiming to save its species from the building of a new financial centre, a mission funded by the developers themselves. Others have not received the same courtesy-every other known intact UK population of this species has been lost to development.  The story of the Streaked bombardier exemplifies the looming threat facing brownfield wildlife, since their habitat is being directly targeted by developers.

Building on brownfields does make logical sense. Not all of them are rare species strongholds. They are generally seen as untidy, abandoned wasteland-gaps in urban landscapes waiting to be filled.

They are even viewed as a public nuisance, since they are often settings for fly tipping, arson and substance abuse, sometimes harbouring dangerous, decaying buildings and reservoirs of invasive species such as Buddleia and Japanese knotweed. Therefore, whilst popular opinion condemns building on undeveloped Greenfield land as damaging to the environment and local communities, new developments on brownfields are often celebrated as ‘regeneration’ projects. Why not make these forgotten plots prosperous again, offering more houses or jobs for people at no cost to the countryside?

The government is doing just that. A week ago, Sajid Javid MP, the Secretary of State for Communities and Local Government announced that plans to meet 2020 housing targets would include development on brownfields. This follows on from government objectives set last year to see “local development orders being used to get permissions in place on over 90% of suitable brownfield land by 2020.”

The sticking point for conservationists is the nature of this ‘suitable brownfield land’.  The National Planning Policy Framework states that previously developed land should be prioritised for development as long as it is not of ‘high environmental value’, yet fails to define what this is. It is known however that over half of the brownfields identified as wildlife-rich in the Thames Gateway were lost to development between 2005 and 2013.

Conservationists aren’t after an all-out ban on brownfield developments. That would be impractical and unlikely to be taken seriously.  They are simply asking for a definition of brownfields of ‘high environmental value’ that would safeguard the important ecosystems and rare species present on some sites.

A suggested definition by conservation experts comprises two conditions:
1- It contains priority habitat(s) listed under section 41 Natural Environment and Rural Communities Act 2006
2-The site holds a nature conservation designation such as Site of Special Scientific Interest, or is defined as a Local Wildlife Site (or equivalent) in local planning policy.

The first condition is largely fulfilled by the latest priority habitat designation, ‘Open Mosaic Habitat on Previously Developed Land’ (OMHPDL). Not the snappiest title, but it is what it says on the tin; neighbouring patches of different habitats, often including scrub, wildflower-rich grassland, earth mounds preferred by ground beetles and ground-nesting bees and wasps, marshy areas, shallow and/or temporary ponds supporting a suite of rare aquatic species and perhaps most crucially bare or sparsely-vegetated ground favoured by warmth-loving insects, pioneer plants and ground lichens (a rare microhabitat elsewhere in Britain – promoted by the high disturbance and/or dumped substrate and pollutants on brownfield land). The presence of these various features as well as the interfaces between them are what make brownfields so rich in species- a broad habitat type greater than the sum of its parts.

A prime example of OMHPDL habitat at Canvey Wick SSSI. Photo c) Steven Falk. Used with permission.

A prime example of OMHPDL habitat at Canvey Wick SSSI. Photo c) Steven Falk. Used with permission.

As it turns out, abstaining from building on areas under this definition of ‘high environmental value’ is not a big ask. Only a tiny proportion (6-8%) of brownfield land fits these conditions. Whilst I would certainly hope that more is spared from development, this is hardly a major obstacle to government housing targets.

Keeping selected areas free from housing is a solution that could suit both parties, but we can only turn the tide on brownfield developments if the government, planning authorities and local communities realise the value of these sites.

There are other solutions for both camps. On the one hand, the work of the RSPB and the Land Trust on Canvey Wick and other sites shows that brownfields can be enjoyed by local communities as public open space with illegal activities prevented by modifying access. On the other hand, development mitigation measures by creating new OMHPD habitat nearby brownfield developments are coming on leaps and bounds, but don’t necessarily cater for the entire brownfield ecology. As far as wildlife is concerned, it would be better not to build on high nature value brownfields in the first place and in the words of the eponymous Aldo Leopold:

“quit thinking about decent land-use as solely an economic problem. Examine each question in terms of what is ethically and esthetically right, as well as what is economically expedient. A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.”

More information on Brownfields and their wildlife :

Buglife Brownfields Habitat Page

Is brownfield development the answer to housing needs? Euan Hall, the Land Trust.

Canvey Wick – Britain’s Rainforest

Colliery Spoil Biodiversity Initiative

Birds thriving on brownfield land despite huge UK bird population declines


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Conservation Ecology graduate, with a particular love for the small things. working in conservation and nature outreach, injecting enthusiasm for entomology wherever I can.

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