UK tree species facing growing threat from pests and diseases

National green services provider, Glendale, is urging UK nurseries to step up biosecurity to prevent the potentially devastating spread of tree pests and diseases.

The company reports that over the past decade, at least a dozen tree pests and diseases have been found for the first time in the UK.

Increasing numbers of threats have also been discovered in areas which make their introduction to the UK a real possibility. Trade, transport, travel and tourism are the key entry routes for invasive species.

In addition, some existing species of pest or infectious disease have become more damaging to UK tree stock in recent years.

Chris Mills, general manager at Glendale Civic Trees, said: “The UK is always at threat from new pest and disease species and with more and more importing happening every year, it’s vital that we step up the biosecurity.

“Ash dieback has been well documented in the media, but there is more on the horizon posing a major threat to trees. Southern Europe is suffering from ceratocystis platani, also known as canker stain of plane, an invasive fungal pathogen which will have a devastating effect on the urban tree population. There’s also agrilus planipennis, a green beetle more commonly referred to as emerald ash borer, which is spreading from Moscow at a rate of 25 miles per year. It’s believed that this insect, which is native to Eastern Asia, has spread through wooden packaging such as crates and pallets.”

While research into treating trees is ongoing, Chris warns that responsibility also lies with people doing the planting to ensure they source quality stock. He said: “There is always research taking place in the background. However, in most cases when a pest or disease has entered the UK it is already too late. An exception to this was the Asian longhorn beetle which was found in Kent. These insects are very slow spreading so they could be contained and eradicated in a small area.

“When planting new trees it’s vital that the trees are selected from a well-established nursery that has tight biosecurity measures in place. Where a tree is already infected, we need to act fast to minimise destruction as far as possible. Anyone worried about an existing tree should contact a local tree consultant who can offer advice on what measures should be taken. There is also useful information available from the Forestry Commission website.

“The spread of disease in trees has a devastating effect on the environment, the diversity of wildlife and our landscape. It will also have significant financial ramifications for the forestry industry and the UK economy as a whole.”

A report by MP Zac Goldsmith in partnership with the Countryside Restoration Trust cites that the total annual cost of invasive species to the British economy has been estimated at approximately £1.7 billion.