Wildlife and Brownfields

Yesterday, Saturday 7th March, I went along to the Staffordshire Invertebrate Fair at the Staffordshire University Science Centre in Stoke.

We arrived at about 11.30 and attended the first talk which was given by Dr Sarah Henshall from BugLife all about the importance of Brownfield Sites for Invertebrates which was very interesting and a real eye opener. The second talk was straight after and all about gardens and bees. Then after looking around the stalls we went along to an identification session on solitary bees which was also very interesting.

One subject I became most aware of today was how important some Brownfield sites are for wildlife. I’d never really thought about it before, I thought that because there had been a lot of human activity in the past and the soil wouldn’t be pure it would be no good but that certainly isn’t the case. I remembered that wildlife can make home pretty much anywhere! Of course not all Brownfields are thriving with wildlife however some are, and some are very important as they are home to rare and endangered species.

What are Brownfield sites?

Brownfields are land that has been altered by human activity (not including farmland or commercial forestry). That doesn’t just include derelict urban areas, but quarries, gravel pits, old railway lines and disused airfields.

They are also known as open mosaic habitats, with pioneer plants, more established flower-rich grasslands, scrub such as heathland, swamp, temporary pools and wet grasslands.

Why are Brownfields so important?

The diversity of species Brownfield sites can support is surprising. For example you may be surprised to hear that Brownfield sites can have as many rare invertebrates species as Ancient Woodlands. Not only that but these areas, often seen a useless or derelict, can form important corridors for wildlife, linking up other habitats.

Brownfield sites provide ‘surrogate’ habitats for species that would be found in other habitats if it were not for human interference. With disturbed soils and bare ground they are excellent for invertebrates and lizards. The burrowing and ground-nesting invertebrates will make their home here along with common lizards that can be spotted basking in the sun and slow worms sheltering under old tins.

They have become the last resort for some species after the intensification of farming which has led to the loss of flower-rich grasslands from the countryside, as well as car parks, warehouses, shopping centres, housing and flood defenses which have left bare ground species with nowhere else to go but Brownfields.

Why are they so rich in biodiversity?

Brownfield sites have gone through cycles of disturbance and abandonment, combined with low nutrient soil which has resulted in a rise to a wide variety of habitats, supplies of water, flowering and a variety of plant species. Many invertebrates have complex life cycles, needing different things at different stages, so they require two or more habitats close to each other, which is what Brownfields provide for them.

Then if there’s one species it’s going to attract other species which builds up a whole ecosystem, meaning not only are Brownfield sites important for invertebrates but they are also important for other animals too. Birds which are attracted include linnet, goldfinch, skylark, song thrush and kestrel. These dynamic landscapes have also attracted rare birds like black redstarts. The flower-rich grasslands provide hoverflies, bees and butterflies with nectar and pollen. Flowers include thistles, ragwort, fairy flax, blue fleabane and rarer orchids, such as fragrant and pyramidal. Along with this, 30 different species of butterfly are associated with brownfield sites, including many common and familiar ones, such as the red admiral, peacock and small tortoiseshell.  Brownfield sites are also key habitats for scarce and declining butterflies such as the Dingy Skipper, Grizzled Skipper, Green Hairstreak, Small Blue, Silver-studded Blue and Grayling. Many species of moths are also found on brownfield sites, including Burnet Companion, Mother Shipton, Latticed Heath, Six-spot Burnet, as well as scarcer species such as the Wormwood Shark. Temporary pools support plants such as horsetails, rushes and the sulphur-coloured yellow flag iris, and are used by common frogs, great crested newts and natterjack toads to live and breed in.

As you can see they are fantastic for a variety of different species, common and rare. Another example which proves that they are very important is the small ranunculus moth which disappeared from the UK before World War II, but it has now recolonised in brownfield habitats throughout England and Wales.

Another feature of Brownfield sites is the open, bare ground. This warms up rapidly in sunshine so it is good for basking on. It is also used by burrowing and ground nesting invertebrates, and provides a foraging area for visual predators.

Plant-eating invertebrates often live in places such as inside leaves, strems, flower heads or seeds and overwinter in places like under logs or stones, or in ground litter. As Brownfield sites aren’t very often disturbed they are perfect places for these species.

How you can help

Various people are interested in Brownfield sites and from an animals point of view, for the wrong reasons. To reduce urban sprawl, government policy adopts a ‘brownfield first’ approach, targeting new developments on available sites within urban areas. This is a good idea in principle, but it doesn’t take wildlife into account.

There are lots of different charities which are supporting the biodiversity of Brownfield sites. You can visiting the BugLife, The Wildlife Trust or Butterfly Conservation websites for more information on how you can help.