Last month Greenpeace launched a petition calling for a total ban on controlled burning in the UK uplands. In response, GWCT chief executive Teresa Dent CBE wrote the letter below to Greenpeace’s interim UK Executive Director, Pat Venditti Esq. offering to meet to present the scientific evidence.
We write in response to points made in your recent article on the extent of controlled heather burning during the last burning season in the uplands of England (Unearthed 30th May 2022) and your response to a GWCT member who questioned the validity of your petition to “Comprehensively ban peatland burning in law and properly fund its enforcement.”
The Game & Wildlife Conservation Trust (www.gwct.org.uk) undertakes research into upland ecosystems including the interactions between heather burning and peatland management (see for example a recent peer reviewed study on vegetation responses to prescribed burning). As a consequence we have written two recent reports on peatland management (GWCT Peatland Report 2020) and the contribution of grouse moor management to public goods and services (GWCT Sustaining ecosystems - English Grouse Moors). It is the evidence from these we would like to draw your attention to as some of the assertions made in your article are factually incorrect or misleading.
“Ban peatland burning”
This is a misleading statement. Prescribed burns (those undertaken in accordance with the Heather and Grass Burning Code endorsed by Defra between October and mid-April when the plant material has dried out, allowing it to burn, while cold, damp conditions underfoot mean the fire is most easily controlled) do not burn into the peat. They remove the surface vegetation through the use of controlled low severity fires that move swiftly across the surface – often termed ‘cool’ burns. Ironically this is supported by the comment in your article that “Blackened spikes of dead foliage protrude upwards, embers from a recent fire”. This is the biochar, produced by the incomplete combustion of organic matter, that remains post burn and which is increasingly being considered a key component of the carbon cycle (see below).
“no scientific sense” and “there is a scientific consensus that all fires on peatland should be banned”
This is factually incorrect; there is no scientific consensus. The links to the documentation supplied to our member did not support either statement. The science upon which the no burn policy on peatlands was based has been challenged – A critical review of the IUCN statement on peatlands - given that, for example, the data was short-term and from single site studies of experimental design which did not take account the carbon budget over a complete management cycle or burn rotation. In addition a seminal piece by Matt Davies in 2016 called The role of fire in UK peatland and moorland management: the need for informed, unbiased debate highlighted the importance of fire as an ecological management tool, particularly in the light of climate change impacts and the increased threat of wildfire, and that this should be separated from political opinions.
“Burning dries out the peat”
This is likely a common misconception as science has yet to distinguish between the effects of prescribed burning and drainage as the two are historically associated. Given that peat is formed from dead vegetation only partially decaying due to the waterlogged conditions, it would suggest that the move to drier vegetation communities is the result of the lowering of the water table due to drainage.
Environmental costs – harm to wildlife, air pollution, erosion of carbon stores, flooding
In the course of your article you refer to a number of environmental costs related to the burning of heather on peatlands. Our recent audit of the contribution of grouse moor management to the delivery of the 25 Year Environment Plan goals, demonstrates that these assertions are misleading and, in some cases, such as ground-nesting bird conservation and Sphagnum moss impacts (Sustaining ecosystems - English Grouse Moors Appendix 3) factually incorrect. Whilst it is not disputed that prescribed burning results in emissions of both carbon and other air pollutants at the time of burn, over the full management cycle these are compensated for by the re-growth of the heather and other vegetation and the formation of biochar, an as yet unaccounted for source of carbon sequestration in peatland carbon budgets. In fact recent research suggests that low-severity fires can help to protect the carbon from decomposition (Flanagan et al Global Change Biology 2020).
However these emissions and the impacts on wildlife are dwarfed by those from wildfires such as seen in the Peak District.
Wildfires are very different to prescribed/ managed/ controlled/’cool’ burns set by upland vegetation managers. Wildfires do risk burning the peat; are not managed or prescribed; burn hot not ‘cool’; do not adhere to the burning code; do destroy vital wildlife habitats; do create risk for nearby dwellings and infrastructure; do contribute to air pollution; can release vast amounts of carbon dioxide, other greenhouse gases and heavy metals embedded in the peat from historic air pollution; tend to happen in summer during hot weather; have no firebreaks built in so can spread rapidly and over marge areas; can be almost impossible to put out without huge fire-fighting resource at huge cost; and even after a fire is put out will leave bare peat and allow erosion.
In our audit we calculated that prescribed burning to create fire breaks to mitigate wildfire risk releases 3% of the CO2e emitted from a wildfire. It is recognised that wildfires result from a build up of fuel (vegetation) in fire-prone ecosystems which heather moorland is, and so the introduction of a no burn policy will be detrimental. In America, a move to no-burn policies by the 1930s is now seen as near disastrous on similar fire-prone ecosystems. A reduction in surface biomass, not just re-wetting, is needed particularly during transition between vegetation communities. This is not just because re-wetting takes time, but also because water tables on peatland drop by 20-30cm in the summer compared to the winter; therefore in many re-wetted situations there will still be a dry layer of peat in the summer which is vulnerable to wildfire. Climate change is the over-riding threat to the continued existence of blanket bog, but wildfire is the second major threat (Defra project No. CTE0513 April 2007).
In conclusion we would suggest that an update is required to the upland evidence base used to develop upland management policy and that the new and evolving knowledge base should be used to inform best practice and develop ecologically-based burning strategies. In other peatland ecosystems fire is a valued conservation tool used to protect and restore globally rare heathland and moorland.
We would welcome the opportunity to present the scientific evidence underpinning the points above to Greenpeace and the author of the Unearthed article, and do hope you will invite us to do so to allow you to make your own evaluation of it.
Mrs. Teresa Dent CBE