‘Works of fiction’: Scientists disparage developers’ biodiversity gain plans

Scientists have warned that developers will be able to manipulate the government’s biodiversity net gain plans for new developments, having examined the schemes of early adopters.

The Environment Bill is set to make it compulsory for most new developments to generate a 10% biodiversity net gain (BNG), based on a metric recently published by DEFRA. 

Several councils and developers are already incorporating BNG into their plans in anticipation of the bill passing. 

Scientists have examined some of these plans and told the Times that they found “multiple flaws” in them, in particular on schemes relying on offsetting BNG. 

One particular development plan to build 210 houses in Betteshanger, Kent, was met with concern by the experts. The site is a former coal mine which has since been reclaimed by wildlife including turtle doves and rare flowers. The developer, Quinn Estates, intends to create a compensatory habitat for the birds at another location nearby. 

Commenting on this plan, Dave Goulson, professor of biology at the University of Sussex, said that the compensatory habitat is likely to fail, adding that “turtle doves are in rapid decline and likely to become extinct in the UK in the next ten years. If it were easy to create habitat for them they would not be endangered.”

Sophus zu Ermgassen, from the Durrell Institute of Conservation and Ecology at the University of Kent, and who also recently criticised DEFRA’s latest biodiversity metric, added that the plan to relocate the birds’ breeding territory violated the scientific principle underlying biodiversity offsetting, that consent should only be given to build on a habitat if there is strong evidence it could be successfully created elsewhere.

When asked if it could guarantee that the turtle doves would move location, Quinn Estates said: “If suitable habitat is made available there is every expectation that it will be found and made use of by the species.”

Tim Shreeve, professor of conservation ecology at Oxford Brookes University looked at a development plan by David Wilson Homes, part of Barratt, for 170 homes to be built on a greenfield site in Buckinghamshire. He said that some of the “species-rich grassland” the developer proposed to plant to achieve BNG was destined to be children’s play areas, rendering it less valuable to wildlife. Shreeve also noted that hedgerows that were in good condition had been downgraded to “moderate”, which he said made it easier to claim they would be improved.

He added: “The biodiversity metrics have been applied with erroneous initial values and the so-called biodiversity plan is really a work of fiction.”

Commenting on the scientists’ criticisms to ENDS, Craig Bennett, CEO of The Wildlife Trusts said that “the so-called metrics” of biodiversity being proposed at the moment “seem crazy”. He continued to say that the concept of BNG “has got the potential, if done right and consistently, and enforced properly, to help in creating nature’s recovery”, but he has concerns with it in its current iteration. 

“Nature is in freefall at the moment, 41% of our wildlife species have declined in abundance since the 1970s. It’s an ecological emergency, we must stop the harm”, he said. 

In a statement Barratt said: “On this development the information used and provided to the local authority follows the relevant and applicable guidance, has been accepted by the local authority and our biodiversity plans will develop as the development progresses through the planning process.”

Responding to the claims made by the scientists, a government spokesperson said: “We have committed to implement an approach to development that will leave the natural environment in a measurably better state than beforehand. To do this, we will be legislating for mandatory biodiversity net gain through the Environment Bill.

“The updated biodiversity metric will underpin this and help facilitate investment in nature’s recovery through clean and green growth that brings nature to people’s doorstep.”