Grasslands fall victim to developers

They are home to rare birds like the skylark, meadow pippet, short-eared owl and grey partridge.

They keep London cool in the summer, absorb air pollution, soak up flood water and offer many inner-city children their only chance of seeing birds and small mammals in the wild.

But London's ancient wild grasslands are losing the struggle to survive against an onslaught from property developers, a survey by the London Wildlife Trust reveals today.

Their destruction will have an " irreversible environmental impact", it warns. The report reveals that in the past 20 years, an area the size of 160 stadium-sized football grounds has been lost in three outer London boroughs. Many more acres have been lost elsewhere or are facing destruction by land-hungry developers.

"Grassland is easier to build on than woodland, which makes these rare sites a desirable target for development," the Trust concluded.

The worst-hit area has been Barking and Dagenham. It has the lowest house prices in London and is a magnet to starter-home developers.

It has lost 96 hectares since 1984. In Bexley, 58 hectares of grassland have been built on. Both boroughs are in the Thames Gateway, where the pressure for property development is at its most intense. It is also the area that Deputy Prime Minister John Prescott has earmarked for major housebuilding in the next decade.

However, the rush to build on grassland could boomerang on the developments which replace them. Wild grasslands lessen the risk of flooding as they act like sponges.

Without them, experts warn, the risks of flooding in the Thames Gateway will only get worse. London's wild grasslands also improve air quality - because the grass and plants absorb harmful airborne emissions. They are an essential habitat for many rare species of birds and bats.

But most of all, says the report, they are "an important element of the London landscape, providing much needed open space and offering recreational and psychological benefits to Londoners".

London Wildlife Trust chief executive-Carlo Laurenzi said: "London's special wild spaces support wildlife of national and regional importance and are vital to the capital.

"If wild grasslands continue to diminish at this rate, the quality of life in London will decrease significantly. We value London as a changing, growing city but regeneration needs to work for both people and wildlife. We urge Londoners and policy makers to get involved in our campaign."