Written by Joe Dimbleby, Specialist Writer
Too often the full story of heather moorland management goes untold because it is obscured by misleading reports in the media. For example, Revive, an alliance of animal rights groups, recently released what it described as a "extremely disturbing" video of "vast swathes of heather upland on fire with flames and smoke billowing for miles." In fact the footage was of controlled burning of small areas to manage heather and other upland plants.
Such burns are regulated and only permitted from 1 October to 15 April when the ground is cold and wet, so minimising the impact of fire on the peat surface. The burned patches then act as a series of firebreaks and greatly lessen the likelihood of devasting wildfire in the summer months. It is often claimed that heather burning is bad for wildlife but it can create conditions that support precious moorland plants and provide vital breeding habitat for endangered species such as golden plover. Therefore, calling for heather burning to be banned potentially puts some of our unique moorland and its wildlife at risk.
In order to counter some of the myths around heather burning and its impact on the uplands, we have identified five common confusions around controlled fire. It is essential that, as the burning season draws to a close, the smoke of propaganda clears and science rather than sensationalism informs the future debate.
1. Heather burning does not burn the peat
The aim of managed burning, often incorrectly reported as “moorland burning” or “peat burning”, is to burn the canopy vegetation not the ground, or surface vegetation, beneath. This leaves the peat unharmed and any damage to the moss and litter layer, which sits on top, is minimised. This method is referred to as ‘cool burning’. If done correctly, the flames can pass over a Mars bar placed on the ground and leave it intact!
2. Heather burning is not the same as wildfire
Wildfire is, by definition, out of control. It burns hotter and over larger areas than managed burns, and it can destroy the peat under the surface. Peat is formed from vegetation that has built up over hundreds or thousands of years. It does not decompose in the normal way because of the waterlogged environment, and therefore locks in huge amounts of carbon, which are released if it catches fire. Peat increases in depth at a rate of approximately 0.5mm-1mm each year, so if a wildfire burns just 10cm, it will take 100-200 years to reform. Due to their rapid unchecked spread, wildfires can also be devastating for wildlife and threaten homes, livelihoods and lives. In contrast, managed burning is controlled by experts and carried out in winter to avoid damage to the peat or wildlife. It is restricted to small patches of taller, more woody heather and removes this high “fuel load” of vegetation, which can otherwise contribute to the devasting impact of wildfire.
3. Heather burning can help moorland plants and animals
Regrowth of heather and other moorland plants can begin within weeks after a patch has been cool burned. Certain species such as sphagnum moss and cotton grass are better at forming peat than other plant species, and these may benefit from managed burning by removing the heather canopy that can otherwise dominate. In addition, moorland birds can benefit from the different heights of vegetation and range of plant species that can result from managed burning.
4. Heather burning can be good for blanket bog
Plants that are particularly good at peat-forming are key to a healthy blanket bog and can be lost if the area is overgrazed or a single plant species like heather is allowed to dominate through lack of management. More work is still needed to understand how best to restore damaged blanket bog. In some circumstances it is considered that simply rewetting (e.g. through blocking drainage ditches) is enough because in those wet conditions, sphagnum can out-compete heather. However, rewetting is sometimes not sufficient, and management is needed to reduce the heather canopy, in order to give sphagnum the space and light that it needs to flourish. In these circumstances, cutting or burning may be needed to reduce that heather canopy, activities for which moor managers require consent from Natural England.
5. Not all moors are the same and on some areas heather burning is restricted
Under the umbrella of “moorland” or “upland”, there is a huge amount of variation. There are heathlands, blanket bogs and grasslands with a wide variety of geography and climatic conditions. A one-size-fits-all approach to management is therefore inappropriate. For example, in some circumstances, there is a case for burning on blanket bog for restoration purposes (as above). Equally, when heather becomes tall and woody it poses a wildfire risk and burning may be one of the tools needed to manage this and prevent the destruction of deep peat, especially on steep slopes where cutting is impossible. So, although there is general agreement to avoid managed burning over areas of blanket bog, it needs to be considered on a case-by-case basis.