Decking and paving threaten London’s wildlife

June 2011: London's gardens - which make up nearly a quarter of Greater London - are changing from green to grey, according to a new study. Garden greenspace in the capital's gardens has been lost at a rate of two-and-a-half Hyde Parks per year driven by recent trends in garden design. While hard surfacing - including decking and paving - increased by more than 25 per cent in the 100 month study period.

VITAL: Gardens are a crucial habitat for wildlife

The report, London: Garden City?, says that the impacts of garden design and management on the environmental role of gardens have to be addressed. Londoners who are not garden-minded may be turning to hard surfacing for practicality, unaware of low maintenance planting alternatives and their many added benefits. While trend-setting garden designs often focus on the architecture of a garden, the function and environmental benefits of vegetation and soils can be ignored.

The report also considered the effect of housing development on garden land. It shows that on average, 500 gardens or parts of gardens were lost to development per annum in London. This equated to about six hectares of vegetated garden land lost to development during each of the years studied – a negligible amount from a city-wide perspective.

The scale and speed of the loss is alarming
But, at a local level, each development accounted for an average loss of 200 square metres of vegetated land, enough to have noticeable local impacts in terms of wildlife resources, flood drainage and climate change adaptation. The Mayor has proposed to strengthen the capital's spatial development plan, the London Plan, to make it harder for developers to encroach on gardens.

‘London's gardens cover a vast area. But the speed and scale of their loss is alarming,' says Mathew Frith, deputy chief executive of London Wildlife Trust. ‘Collectively these losses detrimentally affect London's wildlife and impact on our ability to cope with climate change. It's never been more important that Londoners understand the value of our capital's gardens.

Supports essential wildlife habitats
‘A well managed network of the city's 3.8million gardens support essential wildlife habitat and offer important environmental benefits in response to climate change including sustainable urban drainage,' adds Mathew.

‘We can empirically demonstrate the importance of London's gardens,' says Chloë Smith, the author of the report. ‘Our research emphasises that gardens are a major and valuable part of London's greenspace. In particular, we document the area of London's gardens that is primarily vegetation - 57 per cent of the 37,900 ha of garden (22,000ha) is estimated to be vegetated, that's 14 per cent of London.'

For advice on wildlife and climate-friendly gardening visit www.wildlondon.org.uk/gardening.