Slow The Flow’s Patron, Jack Wallington, writes about the importance of peat for battling both causes and effects of climate change.
Peat has become a hot topic around the world because peatlands are rare and important habitats that support unique wildlife while the peat itself absorbs huge quantities of atmospheric carbon. But peatlands are at risk due to human activity. So, what exactly is peat and how does it work? And why is it important for slowing the flow of water?
What is peat?
Peat is dead, partially decayed organic matter that sits in waterlogged conditions, preventing it from fully decomposing. The main material comes from mosses, including over twenty species of sphagnum moss and various herbaceous plants, such as cotton grass. It occurs in rare locations that allow for water levels to rise and be retained, such as on bogs and moors.
Dead plant material in the water no longer has access to enough oxygen for decomposition, and can sit as peat for millennia. The UK’s peat bogs date to 6,000-10,000 years ago and it takes a year to form just 1mm of peat. This means it is not a sustainable resource because it cannot be replaced in a human lifetime.
Blanket bog is a term used to describe peat that forms in wet upland areas, such as the hilltop moors around Calderdale in West Yorkshire. Here, the large flat areas on the tops of the largely solid stone hills, allow for the build up of water and peat.
Raised bog occurs in lowland areas, where the peat mounds upward over time. It is this peat that was primarily used in the past for garden compost, though its use has been banned by the Government for environmental reasons, which is coming into force over the next year. Alternative peat free composts using sustainable plant waste, wood chips and sheeps wool are considered a better alternative by leading horticulture professionals.
Fen is another peatland, where peat builds up around naturally slow flowing, mineral rich water.
Why peat matters
Although peat bogs can look like barren inhospitable places, the exact opposite is true. Look more closely and peatlands are home to a huge amount of important wildlife. Rare birds such as the hen harrier, curlew, merlin, short-eared owl, they all call peatland home. Plus adders, frogs, toads, lizards, mustelids, dragonflies, carnivorous sundew plants, many moss species and flowering plants – these all need peatland to survive, yet it is all under threat.
Peat is also an incredible carbon store. Around the world 2.84% of land is peat (Xu et al), and 13% of that is in the UK, making us a peatland hotspot. However, according to the Government’s own Natural England department, of the UK’s 3 million hectares of peatland, 80% are damaged due to draining, grazing, burning and other mismanagement.
This is important because healthy peatlands, according to Plymouth University, can store an estimated 3.2 billion tonnes of carbon in the UK alone. They do this through the plants absorbing CO2 as part of photosynthesis, which is then locked in the undecomposed plant material that forms peat. Around the world that amounts to 30% of all carbon stored in soil, according to the Wildlife Trusts, that’s even more carbon than forests – a natural and free form of carbon storage.
Why is peat moorland important for flood prevention?
Peatland is like a giant sponge, it is an incredible water store.
It may surprise people to know that 70% of drinking water in the UK comes from peatlands and when they’re degraded they need costly filtering – paid for by us, the bill payer – and cleaning from the eroded peat (Yorkshire Peat Partnership). Healthy peatlands require far less filtering.
Another concern is that healthy peatlands prevent flooding. They are essentially a form of wetland, peatlands exist because they are incredibly successful at storing huge volumes of water. Degraded peat stores far less water, often because drains and ditches lower the water levels, preventing them from reaching their past natural level, or because the dried peat has eroded away entirely. This has led to increased flooding in valleys over the years beneath degraded blanket bogs because all of the water that led to their creation in the first place simply flows downhill instead.
What can be done?
The good news is that a lot of the damage can be reversed, although in particularly degraded peatland, this may take some time. The Yorkshire Peat Partnership, part of the Yorkshire Wildlife Trust, has had success working with landowners and using pioneering techniques to raise water levels again. This takes time, money and lots of people, but once the water level is raised again, it eventually becomes self managing for the future.
Artwork and photos from Anne Fox, Anne has previously been our artist in residence, as part of a project to promote and interpret the environmental benefits of Natural Flood Management.
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