The 2021 Dartmoor Society Conference –Perspectives on Dartmoor Peat Conservation

Laura White
Laura White
Peatland monitoring station on Flat TorPan, Dartmoor, March, 2021

By Mike Rego

On Friday, 12th November, the Dartmoor Society held their annual conference at the Charter Hall in Okehampton. With over 90 members plus speakers and guests in attendance, the theme of this year’s conference was ‘Hallowed Turf: Perspectives on the Conservation of Dartmoor’s Blanket Peat’ – a highly topical and to many a controversial subject, given all the current discussions on climate and farming on Dartmoor.

Through funding from DEFRA, the South West Peatland Partnership plans to restore some 300Ha of Dartmoor’s peatlands, because healthy peat-forming bog can absorb significant quantities of carbon dioxide from the atmosphere, as well as provide other benefits such as increased wildlife and storage and release of clean water into rivers and reduce the risk of flooding. According to research from the University of Exeter, much of Dartmoor’s peatland has been damaged by drainage, cutting, drying and erosion, and as a result is emitting greenhouse gases into the atmosphere that contribute to global warming. Opinions are divided as to how and where peat restoration should be carried out, and the effect that restoration may have for grazing, access for walkers and horse riders, and potential damage to as yet unrecorded archaeological sites.

Alan Endacott, Vice Chair of the Dartmoor Society, opened the meeting by acknowledging that peatland restoration is seen as a controversial topic to many who live and work on and around Dartmoor. Keith Bungay, former Chief Executive of Exmoor National Park, introduced the topic and the speakers, stressing the value of informed debate by saying that ‘it is too easy to open one’s mouth with strong opinions but not well informed’.

Six speakers were introduced, covering various aspects of peat conservation, explaining how and why it can be beneficial to nature, how it is currently being carried out on Dartmoor, what results may be expected, and more importantly to many, how the historic environment may be protected.

Geoff and Janet Eyre © Chris Chapman 2021

The first speaker was Dr Adrian Colston from the University of Exeter’s Centre for Rural Policy Research, a former National Trust manager for Dartmoor and Manager for Wicken Fen in Cambridgeshire. Adrian’s PhD thesis was based on research on interviews with stakeholders on Dartmoor’s Commons, examining the conflicts between traditional hill-farming methods and preserving historic landscapes within the National Park against a backdrop of climate change and increasing environmental awareness.

Adrian is well-placed to speak on many of the challenges currently being faced. His PhD thesis is available on online (see links at the end of this article) and addresses the history of the Commons through to the present along with the economics of hill-farming, the impacts of atmospheric pollution and the conflicts arising from climate change in what has now been termed the Anthropocene Epoch. This is a proposed new unit of geological time, used to describe the most recent period in Earth’s history when human activity started to have an impact on the planet’s climate and ecosystems, although it is not strictly limited to anthropogenic climate change. (Officially we are in the Holocene Epoch, which commenced some 11,700 years ago with the retreat of the last ice sheets and the rise of humanity, whereas the Anthropocene is proposed as the epoch when humanity started to dominate the planet’s ecological systems and biogeochemical cycles.)

Digging up unexposed peat to make dams on the SE flank of White Horse Hill V2 © Chris Chapman 2021

The meeting commenced with Dr Adrian Colston outlining many of the associated controversies, explaining why many stakeholders with diverse opinions on re-wetting the peat make the project so complex and controversial, despite virtually all recognising the value of peatlands as a ‘Carbon sink’. The major conflict is the debate over re-wetting (the peat) versus re-grazing with increasing stock numbers, with the additional counter-narrative of re-wilding, which can be encapsulated as ‘meat, health and carbon’.

Adrian’s research is based partially on interviews with stakeholders dating back to the 1990s, with updates – as he said, ‘narratives are stories’ with a beginning, middle and end, often of journeys with characters, with villains, victims and heroes, and are peoples’ world views which can contain partial or incorrect information, but tend to be held very deeply. It is only by listening to the stakeholders and their narratives that we can begin to make sense of where we are today and where we go in the future. Adrian admits that it is quite an holistic view of how things have evolved.

Records and personal anecdotes confirm that the Moor is drier now than it was, at least compared to records from Victorian times, but that conservation has only recently come to focus on re-wetting – previously it was all about heather, over-grazing and unsustainable swaling practices, but hydrology is now a major focus. Adrian quoted one (anonymous) hydrologist as stating that whilst Natural England and the National Park Authority reflect back to past landscapes, and say ‘which period of time are you managing back to?’ the hydrologists say that they don’t know and that actually is irrelevant, that if hydrology is restored you then have to wait and see what communities emerge – they cannot guarantee a specific result as the natural outcome will be a functioning landscape rather than a specific historical perspective. And that still leaves the problem of restoration or management of the 80%-90% of the moorland that is not suitable for peatland restoration. Should those areas be grazed, swaled, fenced, or have livestock removed?

Adrian went on to say that essentially one cannot just look at re-wetting the peat without considering the other factors, such as the ‘Molinia jungle’, the effects of atmospheric nitrogen and ozone pollution, and climate change in general. No-one is happy with the current situation, as was highlighted with the fire last year, re-wetting has to work hand-in-hand with other projects. He described Dartmoor as being at a crossroads, at a dangerous time for the future of the Moor as decisions made now will have far reaching consequences for the future. For example there is not enough livestock to graze the Molinia, so sheep migrate to lower areas of sweet grass which can lead to over-grazing. But re-wetting of bogs on areas such as Hangingstone Hill will take a long time to recover – re-wetted bogs provide a water supply for livestock so they will be more tempted to stay in the same areas and graze the Molinia, but there are simply not enough cattle or ponies to provide sufficient grazing.

Prototype equipment built by Geoff Eyre for harvesting heather seeds © Geoff Eyre

Adrian summed up the situation by saying that if what you see with your own eyes does not fit the narrative that you have been following – then question it and find a better narrative, because if you get the narrative wrong you will pursue the wrong solution.

Professor Richard Brazier is a Professor of Earth Surface Processes at the University of Exeter and Director of the Centre for Resilience in Environment, Water and Waste. As a hydrologist, he stated that from a hydrogeological perspective it is not to say do this or do that, but to advise that if a certain course of action is taken, what the likely outcomes may be.

On the left, untreated Molinia grass, and on the right, the results of Geoff Eyre’s work in eradicating Molinia by controlled burning of Molinia and replacement with heather seeds treated with smoking and anti-midge larvae ‘solution X’, and sewn by helicopter Photo Geoff Eyre

Richard began by explaining why peatlands are so important, in terms of a real extent and depth, and radiometric mapping of the Moor indicated that Dartmoor’s peat bogs cover approximately 160km2 of more than 40cm depth, capable of storing some 13 million tonnes of carbon – equivalent to 1/10 of the UK’s greenhouse gas emissions for 2018.Richard demonstrated from maps based upon satellite imaging that Dartmoor is a highly worked landscape, with peat cutting, drainage ditches etc, and so the overall structure and hydrological function is not natural in many areas, with some 29km2 of peatland ecohydrologically degraded.

Monitoring of the peatland restoration at Flat Tor Pan has indicated a generally increasing water table as more water is stored in the peat, with 66% less run-off after storms. Importantly, there was no effect in dissolved organic carbon concentrations, meaning that the effect of restoration was that 2/3 more carbon was being stored than pre-restoration. Additionally, the nature of the carbon being stored was from younger, fresher organic matter, implying peat generation.

Five years post-restoration there has been no significant increase in CO2 being released, but noticeable increases in cotton grass, and a decrease in Molinia. However, whilst a higher water table reduces soil respiration by limiting more rapid aerobic respiration of the peat store, it does promote methane production by microbes in the soil leading to a significant increase in methane emissions post-restoration, however, the methane emissions will typically level off and stabilise five to ten years after restoration as the vegetation changes.

Arising from questions at the end of the first session, Richard pointed out that if nothing is done towards peatland restoration, by 2080 the peatlands will be static or degrading, with the climate being too dry and too warm for sphagnum peat generation, which is why it is so important to bring more biomass back into the system sooner in order to create more resilience to climate change.

The next speaker was Morag Angus, the South West Water manager for the South West Peatland Partnership. Morag started by describing which organisations make up the Peatland Partnership, where they are working in the South West and how they have been funded from 1998 to 2025, with a budget of £9 million for Capital Works and £3.5 million for research and monitoring.

Morag then outlined why peatland restoration is necessary by outlining the stresses that peatlands have been subject to, and in some cases still are; such as drainage, peat cutting, burning, over-grazing, military activity etc., and the fact that this has caused degraded peatlands and mires to no longer function ecologically. In turn, this affects carbon emissions, water quality and quantity, decreases biodiversity, causes a loss of soil and increase in Molinia, degrades the historic and archaeological environment and generally decreases resilience of the peat to climate change.

Morag explained that the ultimate aim for the peatland was hydrological restoration, that it was not just a Capital Works project, and that monitoring and research was a vital component to quantify and understand the gains provided by the restoration work. After outlining what has been achieved to date, some 451ha restored from 2009 to 2021 (equivalent to 2.85% of Dartmoor’s peatland), with a further 900ha due to be restored to March 2025, she went on to describe the planning process, in terms of how the areas for restoration are selected, and how the work is actually carried out.

Explaining the methodology with the aid of various photographs, Morag illustrated the machinery used in restoration, along with the materials and methods and how they were applied to the different topographical features, with a selection of before and after photographs as examples.

Amongst the results of the restoration cited by Morag, based also on similar work on Exmoor, there have been recorded increases of wading birds such as snipe and dunlin, and a significant increase in percentage cover of blanket bog species with four out of six sites showing significant increases of aquatic Sphagnum in standing water created by the restoration, and five out of six sites showing an increase in terrestrial lawn species. As for the future, Morag presented a slide showing that restoration of 931ha on Dartmoor, at a cost of £7 million, would create a carbon saving over
50 years equivalent to 356,186 tonnes.

The first speaker of the afternoon was Kevin Cox, Chairman of the RSPB Council in the UK, a former Chairman of Devon Birds and a former trustee of the World Land Trust. Kevin started by stating that we all have an interest in how the planet survives, that the state of the peat on Dartmoor ultimately affects all of us, there are so many different views and competing interests, and ‘so many people who think that they will be able to free-ride on the actions of others’ but that in this case we cannot argue with the underlying science.

Stating the extent of peatland in the UK – three million ha, making up 10% of UK land area, and 9-15% of Europe’s peatland – it is actually equivalent to 13% of global blanket bog, meaning that we have a significant responsibility for looking after it and restoring it. In the UK we have around 3,000 metric tonnes (Mt) of carbon in store in peat, compared to only 213Mt stored in forest and woodland, however the condition is generally poor with only 23% in a near natural state. Some 40% is eroded, or heather or grass dominated, with 18% afforested, 14% covered in crops and grass, with 5% eroded.

Kevin went on to give examples of how the condition of the peat on Dartmoor has influenced the fauna, birds in particular. Erosion can be accelerated by cattle using peat hags for shelter, and Cranmere Pool, apparently named after the presence of cranes, has not actually seen any cranes for some 500 years. Golden plover have declined with smaller bird sizes and smaller flocks with no breeding pairs currently recorded on Dartmoor, but where the peat has been rewetted, Dunlin breeding pairs at Flat Tor Pan have increased from 16 to 24 from 2010 to 2016. However, Kevin stated that nature-based solutions are only part of the battle against climate change.

Kevin described two ongoing restoration case studies that may be considered analogous to Dartmoor, from Dove Stone in the Peak District National Park and from the Flow Country (Sutherland) in northern Scotland, and pointed out that Sphagnum moss can hold up to 16%-25% of its own weight as water, but that it can take about ten years for a restored bog to store carbon effectively.

Kevin then finished by outlining what he called some of the major myths associated with current popular discussions on the restoration of Dartmoor, starting by saying that although trees can be a good carbon store, and that tree coverage on Dartmoor could increase from 13% to 17%, it all depends on planting the right species. He then went on to point out that heather moorland is only an anthropogenic landscape, not the final mature state, and that burning or swaling on peat is only beneficial if a peat monoculture is wanted as the final outcome, as burning drops the water table, meaning that bogs only recover when the burning stops. He then added that the idea that regular burning prevents wildfires is not strictly true either, as it is estimated that between a quarter and two thirds of all wildfires are a result of escapes from controlled burns. Finally, he explained that the belief that re-wetting kills vegetation is not strictly true either, as over time vegetation returns as Sphagnum moss.

Keith’s presentation clearly aroused interest in the audience, as did that of Martin Gillard that followed. Martin is the Historic Environment Officer for the South West Peatland Partnership, an archaeologist, and stated that the most important bit of all the current work taking place is that of the guys operating the diggers being used in the peat restoration.

Martin has responsibility for preserving the historic environment against the peat restoration, and he went on to explain the process of assessing areas proposed, which consists of examining old records and surveys, and finally walking over the area conducting on-the-ground site surveys, to ensure that potentially historical features such as, for example, an ancient trackway, or perhaps the remains of a granite building are blocked or protected from the restoration process.

Martin explained that it is not always a straightforward process, defining what is historical and should be protected. For example, tramways (often associated with mining and quarrying for instance) are industrial features, and even Phillpotts’ Peat Pass on Whitehorse Hill is not historically old, along with other peat passes only being cut in the 1900s, and then modified by the military in 1963 when it was widened to allow military vehicle access. Additionally, to prevent collapse of the sides, they regularly required re-profiling of the slope angles, and as such, because they don’t hold the original historic form as when first cut, a decision was made to re-profile the sides in order to stabilise them and preserve the overall shape.

Martin countered this restoration work by also stating that in archaeological terms, one aspect of peat erosion is that it has enabled previously unknown archaeological remains to be uncovered, such as the Cut Hill Stone Row and the Whitehorse Hill Cist. However, Martin also pointed out that the volume of peat lost through the historic peat cutting and erosion that enabled the Cut Hill Stone Row to be uncovered – an area of some 20m-80m wide by 200m-300m in length, and over 1m in depth – ‘represents tens of thousands of tons of peat lost, and it’s not a process that is about to stop’. It is also a significant volume of lost carbon storage.
For many, the peat re-wetting process and preservation of historical and archaeological features are not happy bed-fellows, but as for the future, Martin’s role will continue alongside these projects and with the additional funding that has come from English Nature, for each of Exmoor, Dartmoor and Bodmin Moor, there will be a specific Historic Environment Officer working alongside the Peatland Partnership to try and mitigate and reduce the impact of the restoration works on the historic environment.

The afternoon session concluded with a presentation by Geoff Eyre, an Upland Peak District farmer, engineer and agricultural merchant who, in order to restore his own areas of peatland and that of various employers/landowners that he has conducted similar work for, has successfully experimented with his own innovative methods for collecting wild plant seeds, propagating and re-seeding. His presentation was illustrated with over 40 years’ worth of photographs of his work and prototype agricultural equipment that he built himself and successively modified, thereby proving the value of fully understanding the land, and looking for a long-term solution rather than a ‘flavour of the month’ approach.

His initial work was trying to eradicate Molinia grass, and replacing it with heather. Despite being paid to drain the moor this was not enough, so he tried cutting Molinia at least twice in a season, but this resulted in burnt out gearboxes as it is so tough and resistant. He tried desiccating it and then burning it between August to October, which whilst successful in the desiccated areas, was patchy and needed replacement with other vegetation, typically heather, to avoid erosion.

The next step was to harvest heather seeds with a few other species such as cotton grass, and in order to do so, he built his own seed harvesting kit, but germination was problematic, so borrowing a trick used in South Africa (and also by the native Protea flowering plants there), he built a smoke box out of two old household radiators to stimulate germination with resulted in a much higher germination success rate. The next problem was to deal with midge larvae which ate the new seedlings, so he tackled that by developing his ‘solution X’, before finally spreading the smoked and treated heather seeds by helicopter, by adapting an airborne piece of kit normally used for spraying bracken.

Geoff’s method was very successful when applied at Derwent and on Howden Moor, and suggests an ideal procedure especially when targeted on slopes where re-wetting, simply won’t work.

He was very scathing about people who he refers to as ‘desktops’, who claim to have all the theoretical answers but little practical knowledge or direct experience of actually doing the work themselves, and he gave an example of the National Trust who had spent a fortune in re-wetting moorland in Marsden, only to lose it all when the whole lot burnt in a wildfire. In his opinion and experience, a dry peat bog in summer is not a major issue, as come the wetter winter weather it will quickly absorb and store the excess water.

He has tried growing Sphagnum moss from spores on prepared ground – it would only grow on prepared ground after spraying the Molinia and burning it off – but after a number of years there would be an increase in rushes growing which choked the Sphagnum out, so periodic retreatment was required to help the Sphagnum.

He is an advocate of ‘cool burning’ which he has practiced over the years, just taking some 50% of the leaves off of the heather plants which become carbonated but leaving the stalks. To prove his point some years ago that this did not burn the peat, he actually placed six £50 notes under some moss, and demonstrated that after burning, the £50 notes were all intact.

Bracken has been Geoff’s more recent focus. A neighbour retired and sold him an adjacent parcel of land which had some 425 acres of bracken that Geoff was not happy with. It was a mono culture that the sheep would not graze, instead preferring the heather, so Geoff designed a 20-litre sprayer on the back of a soft track vehicle that allowed him to spray 100 acres per day, with the aid of an onboard satnav to keep track of his movements as the bracken was so high and dense.

Geoff quickly realised that when you spray bracken with Asulox, you have to wait a year to see the results for the bracken to die, and it is an expensive chemical to use. So instead, he sprayed with Glyphosate and then burnt some strips through the bracken to see what it did – and he found that after burning he could grow the heather in the treated and burnt strips. Geoff learnt that bracken is allelopathic, which means that it stops other plants and seeds from germinating and growing, but burning removed the toxicity in the soil. The other problem with Azulox is that it heats the bracken that is visible, but it doesn’t stop the secondary regrowth that comes in September, whereas with glyphosate it goes down fully, so glyphosate can be successfully used for spot treatment on the secondary regrowth.

However, the areas where bracken had been removed need to be stabilised to prevent erosion, and Geoff explained how he found the answer in sheep sorrel, so he literally took an ordinary garden lawnmower with a collecting bag up onto the moorland and collected it along with a few other herbs such as bedstraw and put it into the heather growing mix for spreading on the treated bracken strips. The initial result was almost a sorrel hillside, but after a few years the heather came through, and as the sheep sorrel declined in abundance all the other plant species including berry plants returned to give a good mix of biodiversity, without the bracken.The final question session saw two major points of discussion concerning the protection of the archaeology and the treatment of Molinia.

Tom Greaves, past Chairman of the Dartmoor Society and a professional archaeologist raised the point that Dartmoor was, and is, a sacred environment and asked why there appears to have been little co-ordinated effort to focus on the features of the human environment. In response, it was stated by one of the speakers that whilst there is much archaeology to be found in the peat, there have previously been numerous watching briefs for archaeologists to observe the diggers on the moorland 24/7, but at £200 per day and apparently zero artifacts found, it can be hard to justify the expense, so is regarded as a mitigated risk.

Layland Brandfield, who farms at Princetown with a field system, parts of which can be dated back to the Bronze Age, observed that in his experience, Molinia can also be eradicated by glyphosate treatment followed by grazing – subject of course to sufficient livestock.

The conference ended with Vice Chair of the Dartmoor Society, Alan Endacott, commenting that the presentations had successfully brought together the interests of archaeologists, farmers and environmentalists, and that we can learn much if everyone works together, but underlying it all, ‘we desperately need to do the work on peatland restoration’.

Further information about the Dartmoor Society can be found on their website at
www.dartmoorsociety.com/home

The following weblinks can provide more information about some of the organisations and projects mentioned in this article:

A Dartmoor Blog by Adrian Colston
https://adriancolston.wordpress.com/
Dartmoor – by the late Professor Ian Mercer,
Published by Harper Collins, The New Naturalist Library, 2009
Dartmoor National Park – conservation work
https://www.dartmoor.gov.uk/wildlife-and-heritage/our-conservation-work
Dartmoor National Park Management Plan 2020-2025 – draft for consultation
https://www.dartmoor.gov.uk/__data/assets/pdf_file/0025/98611/Dartmoor-National-Park-Management-Plan-2020-2025-consultation-draft-WEB.pdf
Exeter University: Centre for Rural Policy Research
http://socialsciences.exeter.ac.uk/research/centres/crpr/
Exmoor National Park Authority
https://www.exmoor-nationalpark.gov.uk/
Rewilding Dartmoor – Facebook Group (1.8K members)
https://en-gb.facebook.com/groups/213229695546255/
RSPB (Royal Society for the Protection of Birds)
https://www.rspb.org.uk/
South West Peatland Partnership
https://www.southwestwater.co.uk/environment/working-in-the-environment/south-west-peatland-partnership/
South West Water –
https://www.southwestwater.co.uk/
Stakeholder attitudes to the narratives of the Dartmoor Commons: tradition and the search for consensus in a time of change – PhD thesis, submitted by Adrian Colston to University of Exeter, April 2021
https://adriancolston.files.wordpress.com/ 2021/07/thesis-full-v5-viva-corrections.pdf
West Country Bylines – Dartmoor’s wounded land – Parts 1 and 2, by Tony Whitehead, 2020
https://westcountrybylines.co.uk/dartmoors-wounded-land-part-1-how-meaningful-is-protection/
https://westcountrybylines.co.uk/dartmoors-wounded-land-part-two-cause-and-effect/

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