Hallowed Turf: Perspectives on the Conservation of Dartmoor’s Blanket Peat

12 November 2021.

Hallowed Turf: Perspectives on the Conservation of Dartmoor’s Blanket Peat2021 Conference: ‘Hallowed Turf: Perspectives on the Conservation of Dartmoor’s Blanket Peat’

Friday 12th November 2021, Charter Hall, Okehampton

The 2021 Dartmoor Society Conference was held on Friday 12th November at the Charter Hall, Okehampton. An audience of more than 90 members and guests packed the hall to hear six expert speakers give their separate and wide-ranging perspectives on the conservation of peat on the high moor.

With funding from DEFRA, the South West Peatland Partnership is part-way through a project to restore about 300 ha of peatland on Dartmoor, with the aim of improving the absorption of carbon dioxide from the atmosphere, encouraging an increase in wildlife diversity and improving storage and release of clean water into the river systems that originate on the high moor. According to research by the University of Exeter, much of that peatland is emitting greenhouse gases as a result of historic drainage, cutting and erosion.

Our acting vice-chair, Alan Endacott, warmly welcomed everyone to the conference, commenting on the full house and the good proportion of younger faces in the audience. He showed an aerial photograph of the blanket bog on Hangingstone Hill he had taken in May 2012, little knowing then that it and others like it were going to become such an emotive subject. He highlighted the diversity of interest in our upland blanket bogs: to some they are still a place of work, in the tradition of countless generations; to others they are rare places of peace and tranquillity or the sacred realms of the ancestors. Some, like Alan himself, find fascination in studying the little understood hidden archaeology, while there are those who find the continuance of a pastoral economy and the scars left by previous industry abhorrent and who would rather see the uplands left to nature and natural processes.

Alan observed that, regardless of perspective, there is no doubting the role of peat as an efficient carbon store and the enormous value of blanket peat and valley mires as a rare habitat and the source of most of Devon’s rivers, not to mention our drinking water. In the year of COP26 in Glasgow, such matters have been brought into sharp focus. Millions of pounds are currently being spent by the South West Peatland Partnership on efforts to restore large areas of peat on the high moor.

However, the situation is complex. For example, there are environmental costs resulting from this project such as the release of methane – which has been shown to account for 50% of greenhouse gases – as well as the carbon footprint of the project itself, to be weighed against the benefits. It is no secret that the Society, as members of the Partnership and signed up to the principle of restoration, if not the detail, raised concerns earlier in the year about this and other specific aspects of the invasive work involved, especially the level of resources then allocated for researching, recording and safeguarding the cultural heritage. The Dartmoor Society was pleased to see that at least some of these concerns were addressed in the latest funding bid.

Alan explained that the Society felt that communication should be improved and that more could be done to engage with Dartmoor communities and to encourage public debate; hence the decision to hold this conference. He concluded: ‘It’s so important that we get this right for future generations and only right that we should take all perspectives into account to arrive at the best possible balance; and this means talking and listening. I hope that we will hear a lot of positive and enlightening things during the course of the day, including what has been done in other upland areas and any lessons learned in the process. So let’s all keep open minds as we listen to the individual speakers who have so kindly given up their time to prepare presentations and speak to us today and look forward to some good-humoured debate during the question and answer sessions.’

The event was chaired by Keith Bungay, formerly head planner for Dartmoor National Park, then deputy to the late Ian Mercer and eventually chief officer for Exmoor National Park Authority for 11 years. As chair of Europarc UK he developed links and exchanged experiences with European Protected Areas. He has been trustee and chair of the South West Lakes Trust for over ten years and, now living in Exmouth, maintains an active interest in planning, conservation and recreational issues in East Devon.

The first speaker was Dr Adrian Colston from the University of Exeter’s Centre for Rural Policy Research. Adrian is a former National Trust manager for Dartmoor and previously for Wicken Fen in Cambridgeshire. His PhD thesis was entitled ‘Stakeholder Attitudes to the Narratives of the Dartmoor Commons’ and he began by outlining some of the conflicts that arise from the many different claims made on the moor by different ‘stakeholders’ and the varied ‘stories’ that are told according to the focus of the teller: hill farming, wildlife, peatlands, historic landscapes and rewilding. Stories of over-grazing and under-grazing have been joined by others about re-wetting, re-grazing and now rewilding, and what Adrian described as the latest emerging narrative of ‘meat, health and carbon’ – and with it a possible threat to traditional pastoralism.

The re-wetting of peat attracts controversy, despite almost everyone recognising the value of peatland as a ‘carbon sink’. Adrian’s research includes interviews dating back to the 1990s and anecdotal evidence confirms records showing that the moor is drier now than it was in the past. He quoted a hydrologist who noted that while many seek to restore Dartmoor to a specific historical period, a hydrologist will aim to restore a degraded area to a functioning landscape and wait to see what communities of plants and fauna emerge.

Regardless of developments in the relatively small areas of peatland restoration, questions remain as to how the rest of the moor should be managed. Issues include the dominance of Molinia caerulea or purple moor grass, stocking levels and declining biodiversity. Adrian said his perception was that ‘none of the stakeholders are really happy, hill-farm economics are not profitable without tax-payer input, wildlife is in decline, archaeology is becoming enveloped and access to parts of the moor is now difficult and hazardous. One ray of hope, at least to some of the stakeholders, is the blanket bog restoration projects which are returning rare wildlife to the moors and creating an exciting new landscape’.

The second speaker was Richard Brazier, Professor of Earth Surface Processes at the University of Exeter and director of the Centre for Resilience in Environment, Water and Waste. He explained the importance of peat and described the science that has informed the peatland restoration project and the findings from mapping of the high moor. This has demonstrated the extent to which the peat has been affected by the digging of gullies, ditches and cuttings in the past, as well as the location of bare or sparsely vegetated areas. The work predicts that 2,900ha of peatland is ‘significantly and directly ecohydrologically degraded’ and only 360ha is ‘functionally intact’ though fragmented.

Since restoration, monitoring at Flat Tor Pan reveals that average water table depths have increased, as has permanent deep-water storage in the peat soil, and that total runoff from the monitored gully reduced by about 66%. While dissolved organic carbon concentrations remained the same post-restoration, the fact that runoff has decreased means that the total carbon load finding its way into water treatment works, where it has to be removed, has also decreased. Moreover, the carbon in the runoff water seemed to have come from fresh plant litter rather than from deeper and older peat.

Five years on from restoration, findings show there has been no significant increase in CO2 being released, a noticeable increase in cotton grass and a decrease in Molinia. However, the higher water table promotes methane production by microbes in the soil; Richard said these emissions would typically level off and stabilise as the vegetation changes.

He concluded his presentation with slides showing the remarkable mapping tools that are now available, allowing researchers to map not only existing habitat but also changes to that habitat, down to details such as the automatic detection of commercial woodland and hedgerow management.

The third speaker was Morag Angus, South West Water’s manager for the South West Peatland Partnership which operates across four sites: West Penwith, Bodmin Moor, Dartmoor and Exmoor. She began by describing the organisations – private, non-governmental and government, plus those representing farmers and landowners – that make up the partnership and the funding available for the period 1998-2025: £9 million for capital works and £3.5 million for research and monitoring.

Morag outlined the threats to the healthy functioning of peat, ranging from past drainage and peat-cutting works to burning, over-grazing, military activities, nitrogen deposition and climate change. She enumerated the resulting effects: increasing carbon emissions, poor water quality, decreasing biodiversity, a proliferation of Molinia and obscuring of historic features. Stressing that this is not just a capital works project but a holistic approach based on hydrological restoration, Morag said that so far on Dartmoor, the project has restored 451ha, or 2.85% of the moor’s peatland and that the aim of the next phase, ending in March 2025, is to restore a further 900ha.

Describing the planning of each phase of the work, she illustrated her talk with photographs of the wide-tracked vehicles used to get materials to sites. These include diggers whose tracks distribute their weight so efficiently that the pressure they exert is less than that of a human. There were also photographs of the use of blocks, bunds and dams made of either peat or timber sourced from Woodland Trust sites around Dartmoor; of eroded peat sides that had been reprofiled and before-and-after photographs showing water being held in previously dry ditches and gullies.

Results of monitoring on the project so far suggest there is an increase of breeding snipe and dunlin and a significant increase in the mean percentage cover of blanket bog species. At the same time, no signs of the snail that causes liver fluke have been detected.

Morag looked forward to more community engagement and communication, more use of local contractors and more wide-ranging research. She said the partnership was honest and open about how well the project was working, and interested to change, improve and adapt as the situation required.

At the end of the morning session, speakers took questions from the audience.

Q: Methane emissions are 80 times more dangerous in global warming than carbon. How might the Peatland Project be contributing to global warming through methane release and through carbon emission each time a digger moves peat to create bunds or reprofile eroded areas. Can you quantify your total carbon emissions?

A (Richard Brazier): This is not an easy question to answer. Wetland restoration is a matter of short-term loss for long-term gain. We’re looking ahead hundreds or thousands of years.

(Morag Angus): We don’t know our overall carbon footprint. A project in the north has done a carbon account and found that the main factor was staff and contractors travelling to the site. We will certainly do our own account.

Q: Are you doing any other hydrological projects on Dartmoor? For example, the level of the West Dart has dropped dramatically in recent years.

A (Richard Brazier): We are not assuming nothing else has changed. The work on Flat Tor Pan has very local effects and we don’t say they affect river flow downstream. The Environment Agency is looking into this and seeing much more variability in rivers, rain and when it falls. We are monitoring in the Dart Valley with the EA where there are other natural interventions to slow and steady flows, to take the peaks off. Work is needed all the way down the course of rivers so that, in the future, adding many case studies together will give more information.

Q: What happens to the important edges of bogs?

A (Morag Angus): We are aiming at whole landscape recovery and increasingly looking at edges and nature recovery in larger areas, valley mires and wet woodland up to peatland edges. Peat woodland may be useful at edges where peat is shallow and degraded.

(Richard Brazier): Small blanket bogs need protection and gentle transition zones rather than hard edges are important for increased biodiversity.

Q: Is there any bespoke modelling for Dartmoor?

A (Richard Brazier): In 2010 some modelling showed that by 2080 there will be no peat forming on Dartmoor without intervention and with continued climate warming. I don’t know of any modelling that applies that to woodland and valleys but bringing back biomass increases resilience.

Q: Is there any monitoring of areas where Dartmoor is healing itself? In 1983 I photographed the last peat cutting and it’s now difficult to find. I photographed a pristine site recently on Cut Hill.

A (Richard Brazier): Remote sensing work can show this over the three to four years it’s been in use. But vegetation change doesn’t show hydrological change. What may seem pristine may have had a metre of peat removed by cutters, so it may not be functioning in the same way as an untouched bog. It will be losing less carbon if it’s covered, but that covering may be Molinia, which takes longer to form peat than Sphagnum.

Q: The slant seems to be on the environment. Is there enough consultation so that the right long-term decisions are made?

A (Adrian Colston): There is still not enough clarity regarding the future and it’s least clear in respect of farming on the commons. We need to see a joined-up approach from the project that includes farming; hill farmers can deliver public goods.

In the afternoon session, the fourth speaker of the day was Kevin Cox, chair of the RSPB council in the UK. Kevin showed some dramatic images of the effects of climate change and drew our attention to the fact that the UK’s three million hectares of peatland constitutes not only 10% of UK land but also 9-15% of the entire extant peatland in Europe. Peat stores far more carbon than do trees; but much of our peatland is degraded: while 23% is in a near-natural state, 40% is eroded, heather or grass dominated, 18% is afforested, 14% is used for crops and grass and 5% is extracted.

Kevin showed a photograph of Black Tor pan alive with irises, bog cotton, bog asphodel, cross-leaved heath and sundew. He described how the poor condition of much peat has led to the loss of fauna, particularly birds, wondered whether Cranmere Pool, ‘the pool of the cranes’, might one day see cranes again and expressed concern over lapwing, curlew and golden plover numbers. Conversely, where peat was rewetted at Flat Tor pan between 2010 and 2018, dunlin breeding pairs increased from 16 to 24. All uses of peat, he said, should keep it wet and in the ground.

Kevin then described two projects where the RSPB is involved in other parts of the UK. At Dove Stone in Derbyshire, the charity has been restoring peatland in partnership with United Utilities since 2010, helping to create 15,000 dams of peat, stone and heather bales to hold and slow water, and to spread 750,000 handfuls/plugs of sphagnum moss across 750ha of peatland.

In the Flow Country of northern Scotland, the RSPB has been involved in massive efforts to reclaim peat bogs from commercial forestry since 1998. Kevin showed charts of restored water tables and improved carbon sequestration, interspersed, as was his entire presentation, by beautiful images of birds.

He concluded by aiming to debunk what he called major myths associated with restoration projects on Dartmoor. He argued that the moor needed only a limited number of suitable species of tree; that heather moorland is not as important as some people believe; that burning on peat is ‘part of the problem, not the solution’; and that rewetting, far from killing vegetation as some believe, only kills Molinia, bracken and gorse while encouraging the establishment of peat-forming plants. ‘Wetter is better’ was his message.

The fifth speaker was Martin Gillard, historic environment officer for the South West Peatland Partnership. He described his work as the assessment of areas scheduled for re-wetting, using old records and on-site surveys, in order to protect historic features. He pointed out that ‘historic’ is a complicated term, encompassing some relatively recent remains of industries such as mining and quarrying. Even Phillpott’s peat passes on Whitehorse Hill were cut only in the early 1900s and were then modified in the 1960s by the military.

Conversely, peat erosion has resulted in the uncovering of previously hidden archaeological remains such as the Cut Hill stone row and the Whitehorse Hill cist. But Martin said that the ‘tens of thousands of tons of peat lost’ that resulted in the exposure of the stone row is a process that is still going on. Interest in the discovery of archaeological remains has to be balanced with the need to re-wet the peat.

Martin showed photographs from the Amicombe restoration area on the west side of the moor, where various archaeological features have been identified and therefore excluded from the work area. Drivers have GPS on their mobile devices and flags are also put out so that vehicles can be kept away. Elsewhere, sacrifices are made, such as the edge of a tramway that was reprofiled in order to protect the rest of the area from erosion.

Additional funding for the Peatland Project means that a specific historic environment post will be created for Dartmoor. There will also be funds for monitoring and research.

The sixth and final speaker of the day was Geoff Eyre, a farmer, engineer and agri-businessman from the Peak District who illustrated his talk with photographs from 40 years of his own work on the uplands. Addressing the problem of rampant Molinia, he recalled the various methods he has used over the years to control it, including cutting, dessicating and burning. Evidently a natural inventor, he described a machine he designed to harvest heather seed, a bracken sprayer he modified to distribute the seed and the use of helicopters and soft-track vehicles in his quest to restore large areas of moorland.

Geoff expressed some reservations about efforts to re-wet areas. He said that, in his experience, water courses blocked with stone washed out in heavy rain that eroded gullies; and that wooden dams, where they held firm, had created water depths of up to five feet that then iced over in freezing weather. In hot dry summers, the gulleys dried out and cracked, so they didn’t hold water the following winter.

In support of carefully controlled ‘cool burning’ of moorland, Geoff said only the flowers of heather are consumed while the stems survive, and that fire stimulates germination of the seed. Burning into gullies encourages the growth of heather that then stablises the sides. Moreover, the peat is not damaged. In order to prove this, he had once hidden six £50 notes under moss during such a fire and retrieved them later, intact.

Geoff described how he had bought some land with over 400 acres of bracken and devised a 20-litre spray to treat the area with the systemic herbicide glyphosate. With this he could spray 100 acres a day from a soft-track vehicle, after which he burnt the bracken and found that its toxicity had left the soil which he could then stabilise by seeding it with sheep sorrel, tormentil and bedstraw and then grow heather.

The presentation ended with a film that Geoff had made of the many different birds and other wildlife that thrive on his moorland.

At the end of the afternoon there was a short discussion with contributions from the audience on the question of whether enough effort and resources had been focussed on the features of Dartmoor’s human environment, given that it is a sacred site. The Peatland Partnership say there have been numerous watching briefs for archaeologists to observe the diggers at work but that the cost of £200 per day, and the fact that no artefacts have so far been found, make it sometimes hard to justify and that it is therefore regarded as a mitigated risk.

The Dartmoor Society’s acting chair, Alan Endacott, concluded the day, expressing satisfaction that the conference had successfully brought together the interests and views of many different interested parties – archaeologists, farmers and environmentalists – and said that it was vital that the conversations continued urgently, in order to ensure the best outcomes for Dartmoor and climate change, in a spirit of cooperation and communication.

Annabel Crowley with thanks to Mike Rego

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