Recent work through our RSK Wilding/RSK Biocensus Responsible Body has highlighted an issue for the team within the Biodiversity Net Gain (BNG) ecological due diligence process – the presence of peat on site. Peat is well known for supporting high biodiversity, delivering natural flood management, and being an important store for carbon.
The 2023 IUCN report Use of Peat Depth Criteria: Accounting for the Lost Peatlands intended to tackle the issues that arise from proposing development, habitat restoration and other land-use decision-making on the depth of peat in an area.
This report states that:
“The Ramsar Convention defines peatlands as “ecosystems with a peat deposit that may currently support a vegetation that is peat-forming, may not, or may lack vegetation entirely” (Ramsar, 2002). The key feature of this definition is that any area of land with a surface layer of peat can be considered a peatland, regardless of its condition or depth. This is also reflected in the definition offered in the 2022 UNEP Global Peatlands Assessment which states “land with any thickness of in situ peat is a peatland”. Together, these mean that any area currently accumulating peat, or which has done so in the past, can be considered a peatland.”
The historical use of peat depth (based on post-war drivers of exploitability and land capability), is still being used in decision-making, resulting in continued loss of peatlands and the services they provide. The IUCN report notes that peat soils of only 30cm are still sufficiently carbon-rich to exceed the emissions of many other habitats if destroyed, and peatland margins (which include shallow peat) are often biodiversity hotspots because they represent transition zones between differing habitats.
One of the important roles of the Responsible Body within BNG, and of agreeing to hold a Conservation Covenant with a landowner delivering a habitat bank or biodiversity offset, is to ensure the viability and appropriateness of the scheme being proposed. We are not only looking to see that the goals and outcomes are appropriate to BNG regulations/guidance, but also to check that are they relevant to the land and ecosystems within which they are located.
We are used to following guidance that states that if peat is not a certain depth we cannot restore it, and thinking that its value reduces as the depth gets more shallow. The IUCN report challenges that. We are thus moving away from valuing areas of peat based on depth to a ‘peat is peat’ approach, and we need to look more carefully at what is being proposed in those areas.
The presence of peat in an area should encourage a deep dive into the past, present and potential future conditions of the area to ensure that any BNG scheme is aiming for appropriate outcomes and is designed to avoid long-term damage or degradation of this key habitat and to promote restoration wherever possible.
To meet ethical, ecological and climate standards when considering habitat banks in areas of peat, we should be making the most of peat presence, rather than dismissing it based on depth alone. We should be looking for opportunities to restore it where we can.
As a Responsible Body, we are reviewing any habitat bank with peat present and looking to see that:
· peat is not being dismissed based on depth alone;
· hydrology, restorability and wider context are being considered;
· peat presence is embedded within scheme design and details; and
· any departure from peatland habitat restoration is evidence-driven.
Habitat banks have the potential to offer significant ecological and economic returns, and through a robust due diligence process we aim to support these outcomes whilst at the same time giving due consideration to the landscape and to the habitats that were historically present.