
From 2024, the UK’s Environment Act requires planning applications to demonstrate an overall biodiversity net gain of at least 10% as calculated using a new statutory biodiversity metric. But this new legal requirement for developers to demonstrate a biodiversity boost in planning applications could make a more meaningful impact on nature recovery if improvements are made to the way nature’s value is calculated, say researchers at the University of Cambridge.
The researchers trialled the metric by using it to calculate the biodiversity value of 24 sites across England. These sites have all been monitored over the long-term, allowing the team to compare biodiversity species data with results from the metric.
Plant biodiversity at the sites matched values produced using the metric, but bird and butterfly biodiversity did not, which means there’s no evidence that a 10% net biodiversity gain calculated using the statutory biodiversity metric will translate into real-life gains for birds and butterflies, without additional conservation management.
This is the first comprehensive study of the performance of Defra’s statutory biodiversity metric across England. The research was funded by the Ecological Continuity Trust and results have now been published in the Journal of Applied Ecology.
Dr Cicely Marshall, Research Fellow at King’s and first author of the paper, says
"The statutory biodiversity metric is a really important opportunity, and has potential to direct a lot of money into biodiversity conservation from developers. It’s the responsibility of conservationists and policy makers to ensure that it provides a reliable indication of nature’s diversity. At the moment the metric does capture plant diversity quite well, but it doesn’t reflect the intricacies of ecosystems – species like birds and butterflies use habitats in very different ways.
Many property developments have been very detrimental to nature in the past, and it’s exciting that England now has a requirement for developers to leave nature in a better state than they found it.”
The UK is committed to building 300,000 homes a year by mid-2020, so the net biodiversity gain requirement is expected to generate a market for biodiversity credits worth an estimated £135m-£274m annually – substantially increasing funding for nature conservation in England.
Read more about this new study here.