Chloë Smith, Garden Research Officer, gives a bird’s-eye view of London’s gardens

There are more than three million private gardens in Greater London – a significant resource for wildlife and people. Despite the extent of London’s gardens, information about their current use is scarce and concern is growing that changes in use – paving, car parking, development, etc., may reduce their value for wildlife. London Wildlife Trust and GiGL have joined forces to deliver the Garden Research Project to fill this gap in our knowledge.The project is funded by The Wildlife Trusts and the Greater London Authority, both of which have an interest in the value of gardens for wildlife and climate change.

Gardens are central to the Trust’s vision to develop an ecologically functional network of green habitats within London, and to The Wildlife Trusts’ national vision for ‘Living Landscapes’. The results from the project will inform the London Trust’s ongoing campaign to promote and encourage the role of London’s gardens in supporting wildlife.The methodology will be transferable to other organisations for potential future projects.

The Greater London Authority is particularly interested in the apparent loss of London’s gardens. By providing information about where planning permission has been granted for developments, the GLA’s input has been invaluable in tracking trends in changing garden composition and the impacts of development.The research will provide evidence of the value of, and threats to, gardens within the city, so informing policy decisions.

Volunteers have provided access to their gardens, helping to identify broad habitat categories – garden lawn, hard surfaces, tree canopy cover, etc. Using these categories and aerial photographs from two time periods, I am now examining changes in garden land use over the last ten years. Given the impact of housing development, particular attention is being paid to gardens that have been developed within the last three years.

The sampling strategy, designed with expert advice from Dr Dave Dawson, ensures a representative balance of different sized gardens from every borough. Habitat coverage estimates from the sample will enable London-wide coverage to be extrapolated. A Geographical Information System (GIS) model will be developed – mapping garden networks across London and providing information about their biodiversity value and function. This will draw on existing resources managed by GiGL, including data on other green space, climate change modelling and socio-economic indices.

The enormous size of the gardens dataset presents significant challenges for processing, sampling, analysing and presenting extracted data. GiGL’s existing data management and analysis expertise made GiGL the ideal partner for this project.

The data collection phase of the project is now underway and we anticipate preliminary results in the summer. The final findings will be launched in the autumn.