Experts predict a “catastrophic ecosystem collapse” of UK forests within the next 50 years if action is not taken.

Threats to UK forests include competition with society for water, and viral diseases and extreme weather affecting forest management.

A team of researchers from across Europe has produced a list of 15 issues they say are likely to have a significant impact on UK forests over the next five decades.

The study is the first horizon scanning exercise – a technique to identify relatively unknown threats, opportunities and new trends – of UK forests.

Its aim is to help researchers, practitioners, policymakers and society in general, to address threats before they become critical.

Dr Eleanor Tew, first author, visiting researcher at the University of Cambridge’s department of zoology, and head of forest planning at Forestry England, said: “The next 50 years will bring huge changes to UK forests: the threats they face, the way that we manage them and the benefits they deliver to society.”

A panel of 42 experts spoke to colleagues to ask about over-looked and emerging issues that were likely to affect UK forests over the next half a century.

A longlist of 180 items was then whittled down through a series of review exercises to a shortlist of 30 issues.

The panel identified the top 15 issues they believed were likely to have the greatest impact on UK forests in the next 50 years.

The 15 issues were not ranked in order of importance or likelihood of occurrence.

However, when scored individually “catastrophic forest ecosystem collapse” was the most highly ranked issue, with 64% of experts placing it as their top issue and 88% ranking it within their top three.

The term “catastrophic forest ecosystem collapse” refers to multiple interrelated hazards that have a cascading effect on forests, leading to their total or partial collapse.

However, the precise definition of what constitutes forest collapse will vary according to the local context.

The experts also suggest that not all emerging issues are threats – some are new opportunities.

They predict that ‘forest lungs’ will be created thanks to an increased understanding of the benefits of trees for society.

Dr Tew concluded: “These results are both concerning and exciting.

“However, we should be optimistic, remembering that these are possibilities and not certainties.

“Crucially, we have time to act ‒ by responding to the threats and embracing the opportunities future generations can have resilient forests with all the benefits they offer.”

The research, published in the journal Forestry, was funded by Forestry England.