What is OMH? Understanding Open Mosaic Habitats.

Introduction

As Biodiversity Net Gain (BNG) becomes a cornerstone of sustainable development in England, understanding the intricacies of different habitat types is crucial. One such habitat, often overlooked, is the Open Mosaic Habitat (OMH). This article delves into what OMH is, why it’s important, and how developers and stakeholders can navigate the challenges associated with this high-distinctiveness habitat.

What Are Open Mosaic Habitats?

Open Mosaic Habitats (OMH) are a unique type of habitat found predominantly on brownfield sites. They consist of a complex mix of unvegetated or sparsely vegetated surfaces, interspersed with more densely vegetated areas. This creates a dynamic ‘mosaic’ of habitats that can support a diverse range of species. OMH is recognised for its high ecological value, particularly within the context of BNG requirements.

Why OMH Matters

OMH might not always be aesthetically pleasing or immediately recognisable as a valuable habitat, but it plays a crucial role in supporting biodiversity. The combination of bare and vegetated patches provides essential conditions for various species, including rare insects and plants, that might struggle in more uniform environments. These habitats offer critical resources such as nesting sites, foraging grounds, and basking spots for specialised wildlife.

Challenges in Preserving OMH

The recent introduction of BNG regulations has highlighted some significant challenges regarding OMH:

1. Regulatory Conflicts: BNG requires that losses of high-distinctiveness habitats, such as OMH, must be replaced with habitats of equivalent value. However, replicating OMH can be complex and often unfeasible on-site due to the specific conditions required for its formation.
2. Scarcity of Off-Site Solutions: Finding suitable off-site locations to replace lost OMH can be challenging due to the unique conditions that support these habitats. This scarcity can lead to developers resorting to purchasing statutory biodiversity credits, which can be costly and may not always lead to immediate ecological benefits.
3. Urban Regeneration vs. Habitat Preservation: There is a growing conflict between the need to regenerate brownfield sites and the preservation of OMH. Developers can face challenging dilemmas when trying to balance urban development with the need to protect or replace these valuable habitats.

Possible Solutions and Future Directions

To address these challenges, several potential solutions and strategies are being explored:

1. Designated OMH Sites: Identifying and designating specific brownfield sites for OMH conservation could provide a structured approach to managing and maintaining these habitats. Such sites could be integrated into urban planning processes and managed as urban nature reserves.
2. Strategic Partnerships: Collaborations between organisations, such as Natural England and national infrastructure bodies, could facilitate the provision of OMH on a strategic level. For example, using railway land or other large estates for OMH creation may be a viable option.
3. Viability Considerations: Introducing flexibility in the BNG framework to consider viability and regeneration needs could help balance the preservation of OMH with broader urban development goals.

Conclusion

OMH is a crucial habitat that contributes significantly to biodiversity, despite its often overlooked appearance. As BNG regulations evolve, it’s essential for developers and stakeholders to understand the complexities of OMH and work towards practical solutions that support both ecological preservation and sustainable development.

At Integrated Land Management (ILM), we are committed to providing expertise and solutions for navigating the challenges of BNG, including the complexities surrounding OMH. For tailored advice and support on BNG and habitat management, contact us today.