MORE than 2,500 trees will have to be cut down alongside roads in Carmarthenshire because they are diseased –  and the number will rise.

The council has been surveying ash trees along its busier roads in response to the UK-wide spread of ash dieback – a fungus which causes the trees to lose their leaves and become brittle, making them a safety hazard.

Trees showing a certain level of the disease have been marked with orange paint or a tag.

The total number identified to date in Carmarthenshire is 2,512, which are on private as well as public roadside land.

But only 17% of the county’s road network has been surveyed so far, and checks will also take place of ash trees on council-owned land near schools, car parks, cycle paths and council housing developments.

Some felling of affected trees has got under way on the county’s largest roads, which are managed by the South Wales Trunk Road Agent.

Cllr Hazel Evans, executive board member for the environment, said the fate of the UK’s ash trees was “extremely sad”.

She said: “A lot of work is under way by the council to tackle this disease and the risks to public safety.

“It is a serious problem for landowners and councils across the UK who have ash trees on their land, and where people or property are at risk the only option is to fell the affected trees.

“We are also working to raise awareness of the disease, particularly with landowners to offer guidance and advice, as well as the public.”

Surveys of ash trees along smaller roads in Carmarthenshire will follow.

The council said it will use private contractors as well as in-house tree surgeons to begin felling diseased trees.

Ash dieback spread into Europe from Asia, and there are fears it could affect up to 90% of the UK’s 100 million-odd ash trees.

UK expert group Forest Research said there was good evidence that some existing ash trees tolerated the disease, or could even become diseased and then recover.

And the BBC reported last November that a study had identified a gene which gives trees resistance, which may help future populations of ash.

Carmarthenshire Council has an ash dieback disease web page, offering advice to the public and to private landowners.

The web page said: “There will be a need for new tree planting to compensate for the loss of ash trees and we will be seeking funding to support re-planting projects.”