Tree-lined vistas under threat from ‘new ash dieback’
FAMOUS tree-lined avenues such as the Mall in London could be rendered unrecognisable for decades by a calamitous disease spreading across Europe.
The head of the UK’s largest tree management body warned last night that it was only a matter of time before “plane tree wilt”, also known as canker stain of plane, reaches British shores.
The disease has been spreading north through France and is reported to have reached Paris.
Plane trees fill many cities and account for more than half of London’s tree population swelling areas such as Hyde Park, and the Embankment.
The disease, which has already ruined miles of the historic tree-lined Canal du Midi in southern France, is not native to Europe and is thought to have arrived in Italy in wooden US ammunition crates during the Second World War. It is spread by airborne spores or through contaminated tools such as saws and chainsaws, as well as through watercourses and where tree roots intertwine. The disease prevents water circulating in the tree, killing it.
Jago Keen, chairman of the Arboricultural Association, said the lack of plant diversity in British cities, and in particular London, left them acutely vulnerable.
“If the disease gets to London the impact would be catastrophic,” he said.
“It would kill a large number of plane trees very quickly. The Mall would disappear practically overnight, as well as Broadway and Berkeley Square. A lot of the trees in the Mall are 60 to 70 years old, and in Berkeley Square they are 100 plus. We would have to wait that long to restore the current look.”
Experts believe the most likely way for the disease to spread to Britain would be via the tools of a gardener or tree surgeon working on properties in both the UK and France.
Plane wilt could also arrive via in- fected saplings, although it is hoped Britain’s designation as an EU protected zone will reduce that risk.
John Parker, chairman of the London Tree Officers’ Association, said it would be essential to act quickly if the disease reaches the UK.
“If it comes over and it’s not noticed it could be very serious,” he said. “The main symptoms are large numbers of desiccated trees, leaves going grey and orange but staying on the canopy. People should keep their eyes open.”
In March scientists warned that the ash tree was likely to be wiped out in Europe by the fungal disease ash-dieback and the invasive beetle called the emerald ash borer. Hundreds of thousands of young ash trees have already been destroyed in the UK in an attempt to prevent the disease spreading.