ILM’s work at Midloe Grange Farm in Huntingdonshire, for farmer, David Felce, is the perfect example of how it is possible to create a Biodiversity Net gain Site on part of a farm whilst retaining arable productivity on the rest of the farm.

Initially, David identified the areas he would like to assess for Biodiversity Net Gain (BNG) potential early on in the process. He chose smaller fields as well as taking the opportunity to square-ff some larger fields and finding out the potential his existing margins had if they were widened.

The first step for any prospective Biodiversity Gain Site is for ecologists to carry out a Baseline Habitat Survey in line with the UK Habitat Classification System (otherwise known as UKHab). As part of this site, the condition of the existing woodland areas were also assessed to determine whether they had any potential for further enhancement.

Using the Defra Metric, the ecologists measured how many biodiversity credits the areas surveyed generate to derive the Baseline Habitat Value of the site. Following this, using the same Metric, both the new habitats to be created and the existing habitats that could be enhanced were used to generate the Post-Enhancement Habitat Value for the project. The difference between these two values tells us the number of credits that will be available to sell to developers who have a biodiversity offsetting planning obligation.

The arable fields form a ‘blank slate’ from a BNG perspective, on which new habitats could be created. In this instance, neutral meadow has been proposed for the two fields, one of which will incorporate a pond with reedbeds. Each of these elements and habitats have their own ‘value’ in biodiversity unit terms.

A further pond, as well as reedbeds, has been incorporated into the plans for the ends of two existing arable fields, squaring the fields off. New wider margins have also been added to the design of the scheme, allowing for further new habitat creation (in this case, nectar and pollen margins) on what was predominantly arable land whilst retaining arable use across the remainder of the field.

Working alongside David, we have finalised the design of the Biodiversity Gain Site. The next step will be to prepare a corresponding Biodiversity Offset Management Plan, which will dictate how each habitat is to be managed, and the condition criteria each habitat needs to fulfil to meet its target condition.