Around 12% of the world's blanket bog is found in the UK. These special wetlands are valuable carbon sinks, holding as much carbon as half of the Earth's atmospheric levels. Blanket bogs are a vital resource in the fight against climate change, and yet they're becoming increasingly rare.

So what is blanket bog exactly, why is it so crucial in the fight against climate change and what can we do to save it?

Peatland bog at RSPB Forsinard Flows

At RSPB Forsinard Flows, areas of plantation forest are being returned to their original state as peatland. Photo: Andy Hay (rspb-images.com)

What is a blanket bog?

A blanket bog is a type of wetland made up of layers of partially decomposed vegetation. When sphagnum mosses found in these areas die, they are submerged by acidic water. The dead material is essentially preserved and breaks down just enough to form a soil-like material called peat. A new layer of sphagnum grows on top and the cycle repeats, forming layers of peat that can be several metres deep. These bogs are not only excellent carbon sinks but also provide drinking water for much of the UK.

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What is sphagnum moss?

Sphagnum moss, or peat moss, is an umbrella term for around 380 species of moss that can be found in wetlands such as blanket bogs. These mosses can hold up to 20 times their weight in water, and raise the acidity of both the water and soil by releasing hydrogen from the minerals the plants absorb.

What lives on a blanket bog?

Blanket bogs are often protected sites for birds such as merlins and hen harriers. They also support a wealth of invertebrates such as dragonflies and butterflies as well as wading birds, grass snakes and many rare native plants.

Male hen harrier

Bogs and moorlands are vital habitat for ground-nesting hen harriers. Photo: Andy Hay (rspb-images.com)

How do they capture carbon?

Blanket bogs are carbon sinks. This means they take in more carbon than they produce. Oxygen can’t dissolve quickly in water and, paired with the acidity caused by sphagnum moss, microbes usually responsible for decomposition can’t break down the dead plants. The carbon stored within the plants when they died is therefore locked away in the layers of peat as they form, preventing it from entering the atmosphere.

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What happened to blanket bogs in the UK?

In the 1930s, many blanket bog areas were drained for agriculture and forestry use, killing off the sphagnum and reducing carbon storage. When these areas were drained, ditches were dug to make way for forestry plantations and grazing.

As the peat dried out, new moss couldn't grow to form new layers, thus preventing future carbon capture and leading to degradation of the ecosystem.

What does this have to do with climate change?

No longer submerged, the partially decomposed moss is exposed to microbes that begin breaking it down further, exposing deeper layers. As the microbes decompose the organic matter, the carbon once stored in the bog is released. That carbon adds to the elevated levels in the atmosphere, contributing to the increased global temperatures associated with climate change.

Peatland bog Flow Country

The Flow Country is a vital area of peatland bog. Photo: Eleanor Bentall (rspb-images.com)

What is being done to restore blanket bogs?

The EU LIFE-funded project Active Blanket Bog Wales (ABBW) blocked nearly 485km of drains and removed several hectares of forestry plantations, allowing the rewetting of many Welsh blanket bogs. Similar projects across the UK have and are being carried out, often enlisting the help of locals to ensure the importance of restoration is understood and that the voices of those who use the land for farming can be heard.

At RSPB Lake Vyrnwy, EU LIFE funding has allowed for the restoration of blanket bogs. Around 110km of drainage channels were blocked, allowing sphagnum to recolonise vast areas of moorland. Sphagnum has also been transplanted to a similar bog restoration scheme at RSPB Dove Stone.

The RSPB is also undertaking a "Forest to Bog" peatland restoration programme in the Flow Country in Scotland. 

How can we help?

The best way to help fight climate change is to campaign with us. Tell your friends, write to your MP or become an RSPB Campaign Champion – every little helps.

You can also visit one of our reserves to discover this amazing landscape for yourself. Try RSPB Mawddach Valley – Arthog Bog, RSPB Lake Vyrnwy, RSPB Dove Stone or RSPB Forsinard Flows, or visit the reserves page to find a reserve near you.