Peatlands and Uplands

Peatlands and Uplands Project

For 2021-2022, the Bannau Brycheiniog National Park Authority has received £450 000 of funding via the Welsh Government’s, ‘Sustainable Landscapes, Sustainable Places’, fund to restore peatland habitat and repair upland path erosion across the Park. By carrying out these works we will create more resilient uplands and help fight climate change.

Works will commence in Summer 2021 and be completed by Spring 2022.
Project contact: Richard Ball, Countryside and Access Projects Officer (

Resilient Peatlands
There are over 16,000 hectares of peat bog that stretch across the mountains of the Bannau Brycheiniog. Peat is an important carbon and water store but is easily damaged.
Using the Sustainable Landscapes, Sustainable Places funding the Authority will carry out peatland restoration works across targeted upland areas to reduce peat erosion and rewet peat so that it captures carbon rather than emitting it into the atmosphere.

Locations of restoration work include:
Craig y Fan Ddu
Blaen Wen
Pen Trumau
Llyn y Fan Fawr
Southern Erosion Scar, Hatterrall ridge, in the Black Mountains

Resilient Upland Paths
Most upland paths in the Bannau Brycheiniog National Park have developed as a result of recreational use. A large number of these paths have become badly eroded especially where they are on steep slopes or cross peatlands or other poorly drained soils. Erosion of the footpaths that cross our uplands can damage habitats and the peatland that they cross and can damage habitats. During this project upland path repairs will be carried out alongside peat restoration to reduce erosion. This will allow our peatlands to heal, avoiding further carbon emissions from eroded and draining peat, protect in situ historic environmental artefacts and increase the ecological resilience of our land in the face of climate change.

Location of path repairs include:
Pen Cerrig Calch,
Craig y Fan Ddu
Rhos Dirion

Paths have already been repaired at a large number of locations in the National Park. The positive results of providing a sustainable path across peaty areas or on steep slopes can be seen reasonably quickly, at Waun Fach in the Black Mountains for example.

Path works are undertaken by experienced, skilled contractors and our work specifications are designed to ensure that path improvements are as unintrusive as possible. We achieve this by using locally sourced stone whenever possible, taking care to ensure path alignment sits well within the landscape, minimising disturbance to existing flora and fauna by undertaking works outside the bird breeding season and minimising ground damage by airlifting materials to site where necessary.

Why do we want to protect our peatlands?

Peatlands are the UK’s largest carbon store
Healthy peatlands are able to store more carbon than they release, making them important carbon sinks. Due to the acidic and water-logged conditions present in blanket bogs, plants decay very slowly. This results in the slow but steady build-up of peat, which locks in the carbon. On undisturbed, healthy peatlands, peat depth increases at a rate of about 1 mm per year.
Peatlands are vital sources for drinking water.

Blanket bogs and upland raised bogs are sources of streams and rivers and the same is true in the Bannau Brycheiniog National Park, from where Dŵr Cymru Welsh Water obtains at least half of its drinking water supplies on a daily basis. Where the bogs are in poor condition, they release dissolved carbon, other compounds and peat silt, which affects water quality in the Park’s drinking water reservoirs. Gradually restoring the bogs contributes to improving water quality and reducing the costs of water treatment engineering. Upland water storage in bogs is also vital to the viability of future small scale hydro-electricity generation.

Blanket bogs in poor condition release more carbon than they take in
Without plant cover bogs have reduced ability to take in and store carbon. Peat is exposed to air and the elements so it is susceptible to erosion and decomposition and is lost from the moors. This can happen at a rate of up to a metre of peat depth per year in some parts of the UK. Huge amounts of carbon that were previously stored in the peat are released into the atmosphere and rivers. This is why damaged peatlands contribute greatly to greenhouse gas emissions and one of the reasons why it is so important to protect and restore them. They are also home to rare and vulnerable wildlife species.

By protecting and revegetating the areas of damaged blanket bogs, we aim to:
• halt the erosion of peat from the moors
• reduce the loss of carbon
• increase the amount of carbon absorption
• turn the damaged carbon sources back into carbon sinks
• improve water quality
• conserve and enhance the special wildlife of peat bogs
• Heal the landscape and improve experiences for visitors.

Our work can effectively increase the carbon uptake, helping to fight climate change and restore nature
The revegetation and conservation of peatlands allows us to reduce erosion, enhance the quality of the landscape and transform a source of carbon into a sink.
By calculating how much carbon is being taken in and how much is being lost, we are able to assess the impact of land management practices in terms of carbon regulation.
In addition, moorland in the best ecological condition provides better areas for wildlife, and is better able to withstand the shocks and stresses of a changing climate to deliver positive benefits for the communities and settlements downhill, downstream and downwind.

How we are halting erosion

Blanket bogs in this area have been badly damaged by 200 years of atmospheric pollution, as well as a host of other factors including uncontrolled burning and arson, historic heavy grazing pressure and trampling pressure from visitors. This has led to a severe loss of certain important types of vegetation on the hills, resulting in bare and eroding peat exposed to the elements.

We restore bare peat in three broad stages:

Our first step is to stabilise the bare peat to stop any more being lost
In cold weather the higher moors are subjected to repeated daily cycles of freezing and thawing. In hot, dry weather the peat dries out. So both cold and hot weather loosen the surface layers of peat which may then be blown away by the wind and washed away by rain.

Our second step is to stabilise the bare peat so that plants can grow
Once they have established, their roots hold the peat together, stopping any more being lost.

On flat areas and shallow slopes we cover bare peat with cut heather ‘brash’
This protects the peat from erosion and creates stable conditions for seed germination and a micro-climate which helps to protect new plants from harsh weather. The brash contains heather seeds as well as moss fragments and spores. As new plants grow, they form networks of roots that help to keep the peat in place.

Sometimes we re-profile the land on heavily eroded and gullied terrain
Some landforms, such as gullies formed by erosion, have sides that are too steep for heather brash to stay in place. One way of tackling this is to re-profile them. Where we can get access to the gully with machinery, steeply sloping sides can be reduced to gentler angles of 30 to 45°.

Vegetation removed during re-profiling, and which was in danger of being lost to erosion, is planted back onto the newly shaped slopes to help to stabilise them. Elsewhere, we use a water-permeable landscaping fabric (geo-textile) which seeds and plants can grow through and which is completely biodegradable. It stays in place for around three years; that is long enough for seeds to establish and take over the role of stabilising the peat.

Working with water
Rewetting – getting peat bog habitat back into wetter, boggier condition

The problem
A blanket bog in good condition is really wet with the water table (permanently saturated ground) within 10 cm of the surface. Peat erosion has resulted in the drainage of many areas of peat bog in the Bannau Brycheiniog National Park making them much drier. Our conservation work aims to reverse the drying out of the moors in order to rewet the bogs, benefiting water supply and biodiversity.

Across the National Park many blanket bogs are in poor condition and are actively eroding. This leaves the peat bare and susceptible to erosion. Over time, erosion gullies have formed some of which are now so deep that they reach the bedrock. They can be as much as 4 metres deep, draining the peat and drying it out. Elsewhere, blanket bogs have been drained and dried out by the historic policy of cutting ‘grips’ into them, i.e., gridworks of deep, linear drains.

What we are doing to help
Blocking gullies and grips by installing dams reverses these effects by trapping water and sediment, slowing the flow of the water and storing more of it in the peat. This raises the water table providing the conditions necessary for bogs to develop again.

There are two main categories of dam:
• Permeable – using materials such as heather bale, timber or stone. These are designed to slow the water flow and trap sediment which will build up and become vegetated.
• Impermeable – using peat or plastic. These are designed to trap water, creating pools and raising the water table.
The type of dam we use depends on the location, what is available, what is practical and what we want to achieve.

Sphagnum mosses
An active blanket bog contains a special community of plants
The most essential of these plants are Sphagnum mosses – the fundamental peat-building plants. Without these mosses, blanket bog cannot sustain itself, so it is essential that Sphagnum mosses are encouraged where they persist or are reintroduced where they have disappeared.

In some parts of the National Park Sphagnum species have been lost due to industrial pollution, historic burning, heavy grazing pressure, trampling by footfall or a combination of all of these. In many places, Sphagnum of any kind is absent or scarce, and newly stabilised restoration sites are often a long distance from healthy blanket bogs from where Sphagnum could naturally re-colonise them.

To restore the balance, we need to find sources of suitable Sphagnum species to re-introduce onto restored sites. To do this, we use Sphagnum moss in the form of plug plants which have either been cultivated or harvested from local commercial forest sites, which we plant by hand.
A healthy blanket bog has a wide range of plants. If there are no local seed sources near a restoration site, in addition to Sphagnum and heathers, we may plant native moorland plants that have extensive roots to help stabilise the peat, increase the biodiversity of the moors, and provide important habitat and food for a wide range of wildlife.

Prior to commencing any of our peatland restoration and upland path works, we consult with Natural Resources Wales when the sites are within a Site of Special Scientific Interest, with the relevant landowner and the relevant commoners associations because all of the Park’s blanket bogs and raised bogs are on registered common land. We advise the Local Access Forum because all of these sites are also on access land.
Science and understanding
We are building a growing body of scientific understanding as more universities and researchers undertake important research about the impacts of peatlands in poor condition and the benefits of habitat restoration.
Through surveys, we are also building a better understanding of the extent and ecological condition of the Park’s peatlands.

Much of this information has been drawn from Moors for the Future ( ).