Is Strategic Significance Doing Enough?
Strategic significance is one of the more subtle components of the Biodiversity Metric. It is designed to reward habitat creation or enhancement that aligns with wider conservation priorities. In principle, it helps direct investment toward areas that matter most for nature recovery. But in practice, it is worth asking whether it is doing enough to influence decisions.
In Biodiversity Metric 4.0, each habitat parcel is scored for strategic significance using one of three categories. High means the habitat is located in an area formally identified in a local strategy or plan for nature recovery. Medium applies where the habitat is in an area where that type of habitat is desirable, but not formally identified. Low means the habitat is not in a priority area and does not contribute to strategic goals. This score is applied as a multiplier in the biodiversity unit calculation. The idea is that if your habitat creation supports a recognised strategy, you receive more credit.
Determining whether a site qualifies for strategic significance depends on the availability and quality of local evidence. This includes Local Nature Recovery Strategies, green infrastructure plans, biodiversity opportunity areas, Local Wildlife Site networks, priority habitat maps, and other spatially explicit strategies. However, many of these datasets are either incomplete, inconsistently applied, or not publicly accessible. LNRSs in particular are still being developed across much of England.
Local Nature Recovery Strategies are a key part of the Environment Act. They are intended to map out where nature recovery should happen, based on local priorities and ecological opportunity. LNRSs are designed to guide BNG delivery, agri-environment schemes, and investment in green infrastructure. In theory, they are the perfect tool for identifying strategic significance. They can highlight ecological networks, habitat corridors, and areas where restoration would have the greatest impact. But until they are fully rolled out and embedded in planning systems, their influence on BNG remains limited.
This brings us to a more fundamental question. Does the strategic significance multiplier actually make a difference? The multiplier is relatively modest. In many cases, it does not meaningfully change the outcome of a BNG calculation. If developers do not see a clear benefit, they are unlikely to prioritise strategic locations over more convenient ones. If the multiplier does not shift behaviour, it is worth asking whether it is fulfilling its intended purpose.
This issue also connects to the removal of the connectivity multiplier from Biodiversity Metric 4.0. The rationale for its removal was understandable. It was inconsistently applied and difficult to audit. But that does not mean it was unimportant. Connectivity is fundamental to ecological function. Fragmented habitats may appear suitable on paper but fail to support viable populations. During my EngD, I used GIS to model fragmentation using metrics such as core area, nearest neighbour distance, and patch density. These are measurable, repeatable, and ecologically meaningful.
Strategic significance could be one way to bring some of that thinking back in. If LNRSs include ecological networks and corridors, and if those areas are given high strategic significance, we can start to reward connectivity again, even if indirectly. But that only works if the multiplier is strong enough to matter.
The FRIDAS checklist encourages users to reference local strategies and identify whether habitats fall within areas of strategic significance. It does not prescribe how to do this, but it prompts the right questions. In future, a FRIDAS+ approach could go further, helping users assess not just what is in the polygon, but what is around it.
BNG is a powerful tool, but it needs to reflect how biodiversity actually works. Strategic significance is one of the few levers available to align site-level action with landscape-scale goals. If we want developers to care, we need to make sure that lever has real weight.
