Controlled Burning and Wildfire Risk - An Evidence-Based Response to Inaccurate Claims from Scotland: The Big Picture

Catastrophic wildfires across our uplands demand a clear-eyed assessment of risk, not a recycling of tired, evidence-free claims against moorland managers. These devastating events have been seized upon by groups such as Scotland: The Big Picture to renew arguments that controlled burning is a primary cause of environmental damage.

We want to correct the record by systematically holding these claims up to the scientific evidence and the on-the-ground reality faced by those who steward our uplands.

1. What Critics Claim About Controlled Burning

The public debate around controlled burning is often shaped by a series of recurring arguments. While frequently presented as fact, it is vital to scrutinise the evidence, or lack thereof, behind them.

• Claim 1: Wildfire Risk: That controlled burning regularly gets out of control and is a major cause of destructive wildfires.

• Claim 2: Carbon and Peat Damage: That burning heather on peatlands damages the underlying peat, releasing vast stores of carbon and contributing to climate change.

• Claim 3: Biodiversity Loss: That burning harms moorland biodiversity, particularly sensitive species like Sphagnum moss, creating a sterile monoculture.

2. What the Evidence Shows: A Systematic Review

A systematic review of the scientific literature and real-world case studies provides a clear, evidence-based response to each of these claims.

2.1. Controlled Burning is a Vital Tool for Preventing Wildfires

While any use of fire carries inherent risk, the evidence shows that professionally conducted controlled burning is one of the most effective tools for reducing the risk of catastrophic, uncontrollable wildfires. The core principle is managing the "fuel load” - the amount of flammable vegetation. Unmanaged, ageing heather dries out the surface peat and creates a tinderbox, a danger amplified by recent heatwaves that have created "spring-like dryness in summer."

Concrete examples from recent wildfires underscore this point:

• During the Carrbridge and Dava wildfires, land managers with experience in controlled burning were "integral in bringing the fires under control."

• An account from the North York Moors wildfire highlighted how well-managed areas with a low fuel load from recent burning or cutting experienced a much less severe fire. The blaze passed over quickly, leaving the vital peat, root systems, and seed layer intact, whereas unmanaged areas burned severely.

This demonstrates the crucial difference between a careful, 'cool' prescribed burn, which only removes the top-most vegetation, and an intense wildfire that burns hot and deep into the peat. The effectiveness of a proper cool burn was famously demonstrated by its pioneer, the "heather doctor" Geoff Eyre, who showed that £50 notes placed in the moss layer could be left undamaged after the fire had passed over.

2.2. Protecting Peat and Vast Carbon Stores

The argument that controlled burning causes significant net carbon loss from peatlands is directly contradicted by scientific reviews. A comprehensive assessment by Heinemeyer et al. found the claim of "net peat carbon loss" from prescribed burning to be "unsubstantiated" and based on limited evidence.

The goal of controlled burning is to protect the immense carbon stock locked in the peat by sacrificing a small, renewable amount in the vegetation. The comparison is stark:

• The above-ground heather canopy stores approximately 6–13 tonnes of carbon per hectare (t C/ha).

• A severe wildfire burning into peat can release around 96 t C/ha, as was seen in the Scottish Highlands.

UK peat soils hold more carbon than "all the trees in Britain and France combined." Controlled burning converts some biomass into charcoal, a stable form of carbon that resists decomposition.

The choice is therefore unambiguous: sacrifice a few tonnes of renewable carbon in the heather canopy through a controlled cool burn, or risk a catastrophic wildfire that vaporises hundreds of tonnes of irreplaceable, millennia-old peat carbon per hectare. For any serious conservationist, there is no debate.

2.3. Creating a Mosaic for Wildlife

The claim that burning creates a sterile landscape is not supported by the scientific evidence. Reviews, including a major evidence review by Natural England (NEER155), conclude that evidence on biodiversity is mixed and context-dependent, with no generic support for claims of overall negative impacts. Crucially, the review notes that "it can be difficult to separate the influence of burning from that of predator control carried out as part of grouse moor management."

In practice, rotational burning creates a habitat mosaic, a patchwork of heather of different ages and structures. This variety (beta diversity) increases overall biodiversity at a landscape level (gamma diversity). This management, when paired with the legal predator control undertaken on grouse moors, provides ideal conditions for species of conservation concern, most notably ground-nesting waders like the curlew, lapwing, and golden plover, whose populations thrive in these managed environments.

3. A Reality Check on the Alternatives

The main alternatives proposed to controlled burning are not simple, standalone solutions and come with significant limitations.

The Limitations of Cutting

While useful in some situations, cutting can be "worse than doing nothing" for wildfire risk. It creates a layer of dead, dry thatch that is highly combustible and can accelerate the spread of fire. It can also damage the ground's microtopography, flattening the vital hummocks and hollows and creating a "bowling green" effect.

Rewetting: A Vital Tool, Not a Silver Bullet

Rewetting is a vital part of peatland restoration, but it is not a standalone fire prevention tool. Evidence shows it can take decades for vegetation to change, leaving flammable fuel loads in place. Even successfully rewetted moors can dry out on the surface during extreme droughts and remain vulnerable to fire.

4. Why This Matters for Our Uplands: Community and Expertise

The debate over controlled burning is not just about ecology; it is about the safety and resilience of our rural communities. Moorland managers, including gamekeepers, farmers, and estate staff, are the unsung heroes and first responders when wildfires break out.

The response to the Carrbridge and Dava wildfires proved this unequivocally. Private rural businesses mobilised over 100 people and an arsenal of specialist equipment, including dozens of all-terrain vehicles, fogging units, and water bowsers, worth nearly £3.1 million.

The decisive factor was skill: of the 101 private responders who mobilised to assist, 80 had direct experience of using fire through muirburn. Policies that restrict controlled burning through ill-conceived licensing schemes not only ignore the science of wildfire prevention but actively risk dismantling the very private-sector firefighting force that rural communities depend on in a crisis.

Conclusion and Takeaway

When conducted according to best practice, controlled burning is not a threat to our moorlands; it is a safe, science-based, and indispensable tool for protecting them from catastrophic wildfire, safeguarding their vast carbon stores, and supporting their unique biodiversity.

Managing and living on our precious moorlands means using proven, practical tools to protect them for future generations, not banning them based on misinformation.

📧 Keep Updated on All Moorland Issues - Sign Up for Our FREE Weekly Newsletter