Ash dieback to cost economy £15bn as impact of tree disease becomes clear

It's the first time a financial cost has been attached to the fungus and the huge sum has left scientists 'shocked'

Ash dieback could cost the UK economy around £15bn, researchers warn, as the disastrous environmental effects of the disease take their toll.

It’s the first time a financial cost has been attached to tree disease and the research team involved in the study said it highlighted the importance of tree health to both the environment and the economy.

Around half of the estimate (£7bn) will need to be spent over the next 10 years, they said, but regardless of this, 95-99 per cent of the country’s ash trees are expected to die of the disease. Curing or halting it is impossible.

We were quite shocked at the magnitude of the cost to society.

Researcher Dr Louise Hill, from Oxford University, said: “The numbers of invasive tree pests and diseases are increasing rapidly, and this is mostly driven by human activities, such as trade in live plants and climate change.

“Nobody has estimated the total cost of a tree disease before, and we were quite shocked at the magnitude of the cost to society.”

The report, published in Current Biology, added that there are 47 other known tree diseases that could arrive in Britain and add a further £1bn to the estimate.

The costs arise from lost benefits provided by trees, such as water and air purification and carbon sequestration, and clearing up dead and dangerous trees also adds a financial burden.

The £15bn figure the researchers arrived at is 50 times larger than the annual value of the live plant trade to and from Britain, which is the main route for plant disease to enter the country.

The report authors said there were some ways to help the environment fight back, suggesting a widespread replanting scheme could reduce the cost by £2.5bn by replacing the benefits of lost ecosystems.

And they called for an urgent focus on biosecurity to keep new diseases out, with far tighter controls on live plant imports.

“When ash dieback first entered the country, no one could have fully predicted the devastating impact it would have on our native habitats,” said the report’s co-author Dr Nick Atkinson, of the Woodland Trust.

“To see how this has also affected our economy speaks volumes for how important tree health is, and that it needs to be taken very seriously.”

The report came just a day after the UN warned that human activity is pushing around a million species towards extinction in the next few years. This study also listed invasive alien species as one of the key factors contributing to the crisis.

Ash dieback is a fungal disease, originally from Asia, which is lethal to Europe’s native ash trees. It was first found in Britain in 2012 and is thought to have been brought to the UK years earlier on infected imported ash trees.

The team behind the ash dieback findings came from Oxford University, Fera Science, Sylva Foundation and the Woodland Trust.

Image: Phil Lockwood