Moors, wildfires and climate change

Peatlands are the UK’s largest carbon store

Healthy peatlands are important carbon sinks and in the Peak District they store 20 million tonnes of carbon. Moors are therefore important in mitigating climate change and peatlands are important in reducing flooding.

Wildfire risk

Wildfires pose a significant risk to blanket bog habitats and, whether caused deliberately or by carelessness, they seriously threaten fragile moorland habitats. Wildfires in peat can result in severe carbon loss and damage to water supplies, and fighting wildfires is difficult and costly.

Ignition risk map produced using logistic regression model using fires during the period 2009-2018 [i]

Impact of wildfires

Fires can extend for several miles, burning deep into the peat. They decimate plant and animal life and can result in sterilisation of the peat, so that regrowth is not possible without intervention.  Fires can have a disastrous effect on wildlife when birds are nesting and sheep lambing. They are difficult and distressing to deal with and pose a huge financial burden to the fire services and land managers. They also release large amounts of carbon dioxide. (Over 3000 tC was released by a fire on the Roaches on 10 August 2018.) [ii]

Causes of wildfires

Recreation is thought to be the major source of ignition. [iii] However, although wildfires have been logged by Peak Park rangers since 1974 and by the Fire and Rescue Services and others since 2007, it is still not clear what are the initial causes of ignition of many fires other than to say they are induced by people. Of the 423 records of fires in the MoorLIFE2020 database only 48 record the cause which means that the cause of 88% of fires is unknown or unrecorded. [iv]

When do wildfires happen

Wildfires occur during the drier months, especially April-May. To date, most wildlfires have occurred in spring when the dead grass and woody heather ignite easily. In future, as temperatures increase, summer wildfires will become more catastrophic.

Where do they occur most frequently

Fire risk increases on bare peat near main footpaths. [v]  Most fires occur on bare peat, and moorland grass areas, with fewer fires on wet bog communities. If climate change, or rotational burning, encourages a transition from wet bog to dry bog and grassland, fire risk will increase. There were significantly more reported fires on Access Land than on non-Access Land; most fires occurring within 300m of roads and eroded paths, 750m of trampled paths, and within 2km of the Pennine Way. [vi]

Wildfire locations during the years 1976-2003 (A) and 2009-2018 (B). Data from MFFP’s wildfire database 2

Are wildfires increasing

Up until 2020 there is no apparent increase in the incidence of recorded wildfires. 2010 was a particularly bad year.

Number of recorded wildfires 2007-2020 2

Climate change and future occurrence of wildfires

The incidence of wildfires is likely to increase with climate change. Wildfires risk in UK increases in hot, dry weather conditions, especially drought. The main impact of climate change will be to make summers more hazardous. The Peak District is expected to experience warmer, wetter winters and hotter, drier summers, with the risk of wildfire occurrence rising disproportionately with temperature. Modelling by a team at Manchester University and Manchester Metropolitan University predicted little change in wildfire incidence before 2070. [vii] Their models assumed no change in annual visitor numbers, while visitor numbers have increased dramatically since COVID. It is, of course, uncertain that this increase will continue.

Scenarios for average maximum summer temperature 2020-2080 4

Moorland management

Measures to manage moorland to reduce fire risk include rewetting, greater diversity of vegetation, publicity campaigns and signage, controlled burning, and grazing or mowing to remove fuel. Controlled burning can be used to create 10m firebreaks and to reduce fuel load. It is, however, highly controversial, and is now prohibited by law on deep peat (ie ≥ 40cm) and some landowners are trialing mowing as a preferred method of reducing fuel. 

Wetter is better

The key thing that all agree about is that a wet, well-functioning blanket bog is far less likely to burn.  It is also unlikely to release stored carbon.  Moors for the Future, the National Trust, the RSPB and moor owners have been working hard to restore blanket bogs.

To quote the IUCN Position Statement (2021), “The most effective long-term sustainable solution for addressing wildfire risk on peatlands is to return the sites to fully functioning bog habitat by removing those factors that can cause degradation, such as drainage, unsustainable livestock management and burning regimes. Re-wetting and restoring will naturally remove the higher fuel load from degraded peatland vegetation.”

Natural England provide a recent example of the benefit of rewetting over controlled burning – the Saddleworth 2018 wildfire, which started on a driven grouse moor and was eventually stopped by the rewetted areas of RSPB Dovestone.[viii]

Damming gullies on Kinder [ix]

Controlled burning

There is widespread opposition to controlled burning on grouse shooting estates. [x] Recent research has, however, suggested that controlled burning may not be all bad and prescribed burning at regular intervals can increase Sphagnum cover by reducing heather cover and canopy vegetation biomass. [xi] [xii]

However, many conservationists believe that the negative impacts of controlled burning outweigh the benefits. A five-year study by Leeds University funded by the Natural Environment Research Council concluded that: [xiii]

  • Prescribed burning on peatlands was shown to have clear effects on peat hydrology, peat chemistry and physical properties, river water chemistry and river ecology.
  • Burning reduces the organic matter content of the upper peat layers … peat in burned sites is deprived of chemicals which are important for plant growth and for buffering acidic rainfall.
  • Burning vegetation alters the natural peat hydrology in the upper layers of the peat affecting the balance of where water flow occurs. Recovery of many hydrological properties appears to be possible if a site is left unburned over many years.

The International Union for Conservation of Nature (IUCN) updated their position statement on moorland burning this year.[xiv] They argue that

  • scientific evidence shows burning on peatland can result in damage to peatland species, habitat, peat soils and ecosystems,
  • healthy peatlands do not require burning for their maintenance, and
  • restoration management of peatlands is widely achieved without burning.

However, a critical review of the IUCN position statement states “while we strongly agree with several of the statements made within this position statement, it also contains a series of unverified assertions and misleading arguments that seemingly serve to simplify the narrative and paint prescribed burning as a wholly damaging peatland management tool”.

Clearly this is a highly controversial issue plagued by vested interested and misinformation. Whether or not controlled burning is really ecologically sustainable requires further study. [xv]

Tree planting and rewilding

Native woodlands and peatlands are two of our largest natural climate regulating ecosystems. They are both of high biodiversity importance and are a priority for conservation and restoration in the UK. Both have been subject to centuries of loss and damage and both need protection and restoration.   New forest planting on peatland is not supported, however, and growing trees on peatland is not the most sustainable or cost-effective option for tackling climate change.

While planting of commercial forestry dominated by non-native species would be opposed by many on conservation and climate change grounds, encouraging native woodland regeneration (which may include planting) is often supported. It may not be appropriate on deep peat, but it would be in other moorland areas, including clough planting and other drier areas. Broadleaved woodland is generally considered low fire risk and an ideal combination would be wooded cloughs and hillsides, with wet bog on the tops.

What can HVCA volunteers do?

We can volunteer with moorland restoration schemes and replanting. Contact David Hughes, coordinator of the Land Group if you want to get involved and help. hughesonline@btinternet.com

We can also help with education, explaining the consequences of careless behaviour, and we can lobby and persuade, for example to prohibit the sale of portable BBQ.

Questions
  1. Would the moors be treed if there was no grazing and would regeneration occur naturally if grazing was removed? Or do moorlands need managing to retain carbon, prevent wildfires and increase bio-diversity? And if so, how and by whom?
  2. Is controlled burning always bad? What would be the unintended consequences of banning shooting? If we stop landowners from burning/grouse shooting/deer stalking what is going to replace it?
  3. Can we have an informed courteous discussion about these complex questions?
Acknowledgments

I would like to acknowledge the critical help I received in improving this blog and in ensuring the views expressed were balanced and accurate.

Kim Leyland, ornithologist and ecologist.  https://mobile.twitter.com/kimleyland

Matt Dixon, Managing Director of Legacy Habitat and resident of Hathersage. https://www.legacy-habitat.co.uk/meet-the-team.html

References

[i] Dixon, S.G. and Chandler, D. (2019). Producing a risk of sustained ignition map for the Peak District National Park Moors for the Future Report, Edale.

[ii] Titterton, P., Crouch, T., Pilkington, M., (2019). A case study into the estimated amount of carbon released as a result of the wildfire that occurred on the Roaches in August 2018. Moors for the Future Partnership, Edale.

[iii] Glaves D, Crowle A, Bruemmer C, Lenaghan S (2020) The causes and prevention of wildfire on heathlands and peatlands in England. Natural England Evidence Review NEER014. http://publications.naturalengland.org.uk/publication/4741162353295360

[iv] Titterton P (2021) MoorLIFE 2020: D4 – Final Wildfire Database Report: A guide to the methodology used in creation of the wildfire database and an analysis of trends associated with key variables. https://www.moorsforthefuture.org.uk/__data/assets/pdf_file/0028/265690/MoorLIFE-2020-Wildfire-Database-Report-2021.pdf

[v] McMorrow J, Lindley S (2006) Modelling the spatial risk of Moorland wildfire. GeoInformatics Research Group, Geography, School of Environment and Development, The University of Manchester. https://www.moorsforthefuture.org.uk/__data/assets/pdf_file/0031/87646/Modelling-the-spatial-risk-of-Moorland-wildfire,-University-of-Manchester-Report.pdf

[vi] Mcmorrow, J., Aylen, J., Albertson, K., Cavan, G., Lindley, S., Handley, J., & Karooni, R. (2006). Moorland Wild Fires in the Peak District National Park, Technical Report 3. (Climate Change and the Visitor Economy (CCVE)). University of Manchester, Centre of Urban and Regional Ecology. https://www.research.manchester.ac.uk/portal/files/33081545/FULL_TEXT.PDF

[vii] Albertson K, Aylen J, Cavan G, McMorrow J (2010) Climate change and the future occurrence of moorland wildfires in the Peak District of the UK. Climate Research Vol. 45: 105–118

[viii] Glaves D, Crowle A, Bruemmer C, Lenaghan S (2020) The causes and prevention of wildfire on heathlands and peatlands in England. Natural England Evidence Review NEER014. http://publications.naturalengland.org.uk/publication/4741162353295360

[ix] High Peak Moors (Kinder and Bleaklow)  https://www.iucn-uk-peatlandprogramme.org/projects/high-peak-moors

[x]  Gatten E (2021) Ban of heather burning on peat bogs in blow to grouse moors. The Telegraph 29 January 2021.

[xi] Whitehead S, Weald  H, Baines D  (2021) Post-burning responses by vegetation on blanket bog peatland sites on a Scottish grouse moor Ecological Indicators 123 (2021) 107336  https://www.sciencedirect.com/science/article/pii/S1470160X21000017

[xii] Heather burning on blanket bog: The long-term effects for vegetation https://www.gwct.org.uk/wildlife/research/upland-biodiversity/heather-burning-on-blanket-bog-the-long-term-effects-for-vegetation/

[xiii]  Brown, L. E, Holden, J. and Palmer, S. M. (2014) Effects of moorland burning on the ecohydrology of river basins. Key findings from the EMBER project. University of Leeds. https://water.leeds.ac.uk/wp-content/uploads/sites/36/2017/06/EMBER_2-page_exec_summary.pdf

[xiv]  IUCN (2021) Burning & Peatlands https://www.iucn-uk-peatlandprogramme.org/about-peatlands/peatland-damage/burning-peatlands

[xv]  Davies G, Kettridge N, Stoof C, Gray A, Ascoli D, Fernandes P, Rb Marrs R, A. Allen K, Doerr S, Clay G, McMorrow J, Vandvik V (2016) The role of fire in UK peatland and moorland management: the need for informed, unbiased debate. Philosophical Transactions of the Royal Society B. https://royalsocietypublishing.org/doi/10.1098/rstb.2015.0342

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