Forestry, carbon and peaty soils

Expanding woodlands and restoring peatlands are critical to address the twin crisis of climate change and biodiversity loss.

A careful balance between woodland creation, restocking and peatland restoration is needed.

Forestry and peatland can interact in different situations. These will need legal and/or guidance considerations.

Here are the three ways that forestry and peatland can interact:

1. Creation of new woodlands

Planting should be avoided on deep peat (50cm or more)

It should also consider priority habitats, species and hydrological effects if planting next to peatlands.

2. Forest-to-bog restoration

This may happen on legacy sites where forests were planted on deep peats. 

Forest to bog restoration

Note that:

• these sites are now reaching first rotation
• forest-to-bog restoration could be an option at these sites
• woodland removal will need felling permission

How to apply to fell trees

3. General good forestry practice 

Good practice is required to protect soils in all situations. 

Forestry activities like cultivation and harvesting can have adverse impacts on soil. Following sustainable forest management principles can safeguard soils.

UK Forestry Standard, 5th edition

Managing woodlands to combat climate change

Peat soils and peaty soils are different to one another.

Peat has its own soil types such as blanket peat or basin peat. They are generally deep peat (50cm depth or more). 

Peaty soils however, are a collection of different types of soils, which contain some peat in its layers. Peat is made up of partially decomposed plant (organic) material. Peat soil is defined in Scotland as:

• having at least 35% organic carbon in the organic surface layer
• the organic surface layer is at least 50cm in thickness

Peaty soils are often referred to as organo-mineral soils. These contain moderate amounts of organic matter. They are soils that are in transition between a mineral and an organic soil. In Scotland, types of peaty (organo-mineral) soils include:

• peaty gley
• peaty podzol
• peaty gleyed podzol
• peaty alluvial soil 

These peaty (organo-mineral) soils can be planted with trees in the right conditions. 

Peat soils with a depth of 50cm or more cannot be planted with trees. 

Careful consideration is needed before planting any trees. 

Using soils data or doing a soils assessment at a site may be needed. This is to ensure planting does not occur on deep peat; nor impact the hydrology of nearby peatlands. 

Read our page about soils data and assessment for further information.

Soils data and information

More information on soil types can be found on Scotland’s Soils website.

Guide to soil types (Scotland's soils website)

The origins of the 50cm deep peat threshold in Scotland can be traced back to 1970 in the Soil Survey of Scotland.

Origins of the Soil Survey of Scotland 50cm threshold to define a Peat soil (archived Scottish Government website)

The UK Forestry Standard outlines that no new forests are to be established:

• on peat depths of 50cm or more
• or, where it compromise the hydrology of adjacent bog habitats

Planting new woodlands on deep peat in Scotland not permitted.

As part of the review process for the UK Forestry Standard's 5th edition:

• it was agreed the 50cm deep peat threshold be retained
• there was no settled scientific evidence on carbon balance or tree growth rate to support lowering the threshold from 50cm
• each UK nation can define their own thresholds if required

UK Forestry Standard, 5th edition

The UK nations will continue to support evidence gathering and any changes in evidence will be reflected.