Western Morning News (Saturday)
Long-term benefits of restoring our peatlands
Dartmoor holds the largest expanse of upland peat in southern England. It is internationally important for the wildlife of its rare blanket bogs and stores up to 10 million tonnes of carbon. But its full potential is far from being realised. The RSPB’s Tony Whitehead describes the value of restoring these special places
ACCORDING to a university research team one of the Dartmoor landscape’s most significant features is in very poor shape. The University of Exeter mires research team reported in 2017: “It is estimated that 29 square kilometres (2,900 ha) of the peatland extent is significantly and directly ecohydrologically degraded by drains, peat cuttings, erosional gullies and bare peat”.
University of Exeter researchers have mapped the peatland in great detail. They had been commissioned by the National Park Authority and South West Water and found the peat in an appalling condition. The majority was degraded, and they found only 360ha that was ‘functionally intact’ – in other words, working as a peatland should.
As anyone who knows Dartmoor’s history will tell you, the peat has been exploited for a long time. It has been cut for numerous reasons over the centuries, and even on an industrial scale for the moor’s failed naphtha industry. It has also been drained for agricultural ‘improvement’ and it has had ‘passes’ cut into it, initially provided by the local hunts so that old Reynard couldn’t escape the horses and hounds by disappearing into the mire.
It has also been bombed and driven over by military vehicles for decades. As MP Anthony Steen noted in the debate around the Dartmoor Commons Act in 1984: “It has been remorselessly pounded by the military, creating 50 craters per acre in the blanket bog.” (Hansard, 25 June 1984)
It’s little wonder that it is in such a poor condition, the rich peat washing away in deep gullies between dry desolate hags. It’s this erosion that revealed the famous Whitehorse Hill kist, and it is this continued erosion that threatens it.
The peat on the high moor, at least half a metre thick, is the basis of the blanket bogs. The UK is hugely important for this rare habitat, with 10-15% of the global resource.
Where it survives in good condition, walkers will be familiar with its jelly-like surface of sphagnum moss, dotted with sundews, cotton grasses and asphodels. If lucky, those who venture onto the high moor in summer may encounter one of Dartmoor’s special birds, the dunlin, here at the very southern edge of its global range and a species intimately linked to blanket bog.
Aside from its wildlife value, a properly functioning blanket bog serves us well in other ways. If it’s not eroding, then it is storing carbon and plays its part in our common struggle with runaway climate change. Indeed, in Devon, the peatlands are probably of more significance than the currently popular movement for tree planting in this respect. If we don’t look after it, any tree planting we do elsewhere will not offset the loss in terms of carbon.
The blanket bog is also the source of nine rivers. When it is working properly, it acts as a colossal sponge, absorbing water in times of flood and delivering clean, naturally filtered supplies in times of drought. Approximately 45% of the 157 billion litres of water annually supplied by South West Water is extracted from Dartmoor’s rivers and reservoirs. These things it will do for us for free, and yet have huge value. Money invested in peatland restoration is a handsome investment.
In response to the need to restore the peat, the Dartmoor Peatland Partnership was established, involving a wide range of organisations with the right skills and expertise to deliver real change. The restoration work was also agreed by the Forest of Dartmoor commoners as one of the key outcomes of the Farming Futures project that received financial support through a Higher Level Stewardship agreement. The project has had two phases, a pilot between 2010 and 2015, and the current work, funded by Defra, in 2018. Its work is focused on five sites on the high moor.
The overall aim is to ‘re-wet’ the peat. Without water, there will be no natural regeneration of the blanket bog.
To do this, dams are placed along ditches and erosional gullies, diverting water out of the ditch and across the land surface or through the peat soil.
This sounds simple, but the practicalities are challenging. The high moor is remote and in places difficult to access. And the work needs to be done in winter to avoid nesting birds. And of course, any groundwork on the moor has to carefully avoid any archaeological remains. To this end, the project employs the services of professional and knowledgeable archaeologists to closely monitor what’s being done. It’s worth bearing in mind as well that the peat in good condition helps to preserve the moor’s prehistory. Perhaps more urgently for the people working up there, careful tests are also carried out to identify any unexploded ordnance. All of this increases difficulty and cost. But the early results are wonderful. Already 1.8 square kilometres (180ha) of degraded blanket bog has been restored and rewetted. In response, there has been a significant increase in the extent of sphagnum and bog cotton grass. Equally, snipe have increased in numbers in the re-wetted areas and, best of all, the dunlin numbers are going up significantly. Back in 2010, before any restoration works had been carried out there were an estimated 16 dunlin breeding territories. This increased to up to 24 territories at the last full survey in 2018, with the increases associated with the restored areas.
While it will take a decade for the blanket bogs to fully recover, it is amazing how quickly they respond. Given their value, and given how they help us, we must now look with urgency to restore much larger areas of blanket bog on Dartmoor.
The National Park Authority declared a climate and ecological emergency in 2019, and this year the UK hosts COP26 in Glasgow, the conference of world governments on climate change. Wouldn’t it be great to showcase what we are doing here on Dartmoor – and for us to publicly commit to complete restoration of our blanket bogs and make these special places something of which we can be proud.