How we are helping ancient peatbogs to breathe again

By Calum Brown, Co-Chief Scientist, Highlands Rewilding  

When Robert Louis Stevenson wrote that “the world is so full of a number of things, I’m sure we should all be as happy as kings,” he may well have been thinking of his native Scotland. The natural potential of Scotland is immense, but often underappreciated.   

One of Scotland’s greatest hidden secrets is peat. Covering around a quarter of the country, peat is a huge natural carbon store that also soaks up water and supports unique ecological communities. Globally, peat stores around 30% of the world’s soil carbon, 10% of freshwater and 50% of wetlands (themselves hotspots of biodiversity), despite only covering 3% of the land area. Noticed by few and appreciated by even fewer, the humble peatbog represents a super-charged reserve of a number of very important things.   

Scotland has 13% of the planet’s blanket peatbogs. If we re-scaled the world map according to these crucial habitats, Scotland would be in the global top 10. This makes us a frontrunner for ‘Nature-Based Solutions’; changes that use the power of natural ecosystems to help solve some of our greatest challenges.  

However, almost all of Scotland’s peatbogs are currently degraded. One of the main causes of this degradation is historical forestry. In the 1980s, especially, large areas of peat were drained for conifer plantations to achieve a much-needed boost in domestic timber production. But this had an unintended consequence. Ditches and thirsty young trees dried out the peat, causing it to start emitting – rather than sequestering – carbon. It has been estimated that 20% of Scotland’s annual carbon emissions now come from damaged peatlands.  

At Bunloit Estate, we’ve been mapping and measuring peatbogs and their condition for several years. Here we have peat up to 8 metres deep – so deep that it might have been forming for 8,000 years, more or less since the last ice age. But in the past few decades, it’s been drained and planted on, turning a huge carbon sink into a source of approximately 1,000 tonnes of CO2 per year. 

An early study on Bunloit used satellite images to track ‘bog breathing’, the process of peatbogs absorbing water in the wetter months (breathing in) and gradually releasing it in the drier months (breathing out). In a healthy peatbog, this cycle is accompanied by a slow increase in surface level as peat gradually accumulates. In degraded peatbogs, like some parts of Bunloit, movement looks more like a slow, halting release of breath, as water drains away and the surface subsides.  

In recent months, we’ve carried out work that’s been years in the planning, starting to restore a large area of peatbog that was previously planted with commercial conifer forests. On the deepest peat the trees never grew more than a few feet high, but in other areas they formed almost impenetrable thickets above the deep drainage ditches.  

The first step here has been to remove the plantation entirely (and thin the trees out in surrounding areas so that more light and species can get in), taking out around 3,000 tonnes of timber. Working with Peatland Action, we’ll soon move on to blocking drains and ‘zippering’ together the ridges to create a more uniform, flatter surface on which a natural water table can re-establish itself. This work will hopefully be completed later this year, after which we should see peatland species returning, and carbon emissions reversing, over the coming years. The bog will finally be able to breathe in again. 

Restoration of this kind is happening more and more in Scotland, but there’s a lot still to do. Nationally, around 50,000 hectares of peat had been restored by spring last year, but the Government hopes to reach 250,000 hectares by 2030. This requires rapid acceleration of current progress, even as changing climatic conditions exacerbate the threats of drainage and fire. 

Whatever the difficulties, restoring peatland remains one of the most obvious and powerful things we can do to reduce emissions and increase biodiversity. It might not be the most charismatic or dynamic part of nature, but peat is one of our greatest natural allies. It provides some badly needed strength in depth!