If you are a property developer or commercial contractor, the term Biodiversity Net Gain (BNG) is a phrase that will strike fear into the heart. After weeks of designing and constructing, you think you’re almost ready for the next stage of the project. And then suddenly, a new requirement lands on your desk: a complete report of all the biodiversity gains from your development. You may be imagining rows of tractors idling as they wait for the ‘all clear’ from the environmental health team.
The simplest way to explain this process is that developers must prove their construction project contributes to a net increase in biodiversity on site. It’s anecdotally often referred to as ‘10% more wildlife’ but of course it’s much more complex than that.
Ensuring biodiversity compliance for a development is an extra layer of complexity for a project but there is good news for developers. There are trade plants that are designed to score very high on BNG audits. ‘Trade plants’ refers to plants that are not native to the area but are well adapted for the climate and soil conditions of your site. While they may not score as highly in terms of ‘biodiversity potential’, trade plants are much easier to specify and create than native species. These plants are used to demonstrate that the development meets the required standards and while native plants would score better, it is still better to specify a few very productive trade plants over just using lawn. For Plants for Trade, visit www.palmstead.co.uk/plants
When conducting a BNG audit, the environmental health team will be looking for biodiversity opportunities in three main areas: structural features, soil structure and micro-habitats. First up, structural features. While the aesthetic appeal of native species is undeniable, structural species are also worth specifying. Native plants such as Hawthorn (Crataegus monogyna) or Hornbeam (Carpinus betulus) have many characteristics that score very well in a biodiversity audit.
Hawthorn for example can provide nest sites for birds and seeds for small mammals, while Hornbeam has beautiful catkins to attract pollinators. They also have dense growth to provide shelter from wind and elements and in autumn, they drop yellow leaves and produce red berries. Structural species such as Hawthorn or Hornbeam should be specified at the site boundary to take advantage of this high scoring feature.
There is also no need to specify any more features, as these plants have multiple uses and will therefore score well. If you want to specify extra features to score very high on your BNG audit, try to choose plants that are native to the area and provide a variety of different features such as nesting, pollination, seeds and shelter. You can also choose plants with edible berries or leaves to improve biodiversity potential.