Summer wildfires caused 'catastrophic' hidden damage, scientists warn

Scientists investigating the damage caused by severe wildfires across Wales this summer say the impact has been "catastrophic".

Extreme heat and exceptionally dry conditions throughout July and August left landscapes such as heathland, moorland and upland grasslands vulnerable to fast spreading fires, resulting in one of the UK's worst wildfire seasons in recent years.

Professor Davey Jones, who is leading a Bangor University survey of several sites across Wales, said the scale of damage was far greater than what was immediately visible.

"People see the blackened vegetation and assume that's the main impact, but the real story is below our feet," said Jones.

During the July peak, fires affected approximately 2,760 acres of countryside across north Wales alone, the equivalent of more than 1,500 football pitches.

At Sychnant Pass in Conwy county, one of the most significant blazes saw 36 homes having to be evacuated and around 200 acres of land affected.

At Sychnant Pass today, there are slight green shoots of recovery visible among the charred hillside.

But Jones described a rare ecosystem housing specialist plants, butterflies and insects, "where the UK is the epicentre globally".

"We've probably lost about 10 centimetres of soil here [at Sychnant Pass] so we've lost all of that organic matter layer.... 4,000 years of carbon gone in a single event," he said.

"Once the topsoil is gone, we can never recover that.

"People see the blackened vegetation and assume that's the main impact, but the real story is below our feet.

"This soil acts as a water sponge, a carbon store, a nutrient bank.

"Losing it is a double whammy, it worsens climate change and makes the habitat far more fragile."

He added, "This site has taken thousands of years to develop and it's all gone in maybe five days? It's incredible.

"If we are going to try and put that soil back, generate artificial soils through the reuse of organic wastes for example, then it's important we understand what the soil quality is now.

"So that we can prepare for the future and design those soils, because they don't exist yet."

Over recent weeks the Bangor team has been racing to collect soil samples at several sites across Wales before heavy winter rainfall washes away the remains.

Their work has included comparing the burnt land with adjacent untouched areas, allowing researchers to measure changes in soil carbon, nutrients, microbial activity, water repellency and erosion risk.

Even NASA satellite data has been used to quickly identify new sites after fires have occurred.

Dr Kara Marsden, a lecturer in soil science who is also working on the project, said working at speed was vital.

"It was really important that we got on site very quickly to measure the soil and vegetation properties while the fire's impacts were still fresh," she said.

"These things can change rapidly, so capturing that baseline data now means we'll have something accurate to compare against in future sampling dates."

She warned that early green shoots now visible at the site did not necessarily reflect true or full recovery.

"Bracken sprouts almost immediately because its rhizomes sit deep in the soil, so the burn layer wouldn't maybe have impacted those" she said.

"But the heather and gorse have much shallower roots, so you know they're completely gone.

"They've been completely lost... that depth of soil they depend on could take thousands of years to form again."

Jones said that the impact of such wildfires extended far beyond biodiversity loss.

"Fires release carbon, nitrogen and sulphur back into the atmosphere, in itself contributing to climate change," he said.

"Every time we have a wildfire, we're just making the problem worse and worse.

"It becomes a self‑sustaining cycle... drier soils, more fires, more carbon released."

He also warned that without rapid restoration and better wildfire preparedness, "we might lose pretty much all of this habitat within our lifetime".

Researchers will return to the sites over the next two years to track recovery and assess whether some habitats are more resilient than others.

Early evidence suggests vegetation can return, but more slowly and more fragile, leaving landscapes increasingly susceptible to future burns.