NATIONAL Trust chiefs say they are "worried" but remain "hopeful" after deadly ash dieback disease was found in mature woodland near Luccombe.

The potentially devastating fungal infection Chalara fraxinea was confirmed by Defra this week after being spotted by trust rangers in the Blackford Plantation.

The five hectares woodland is dominated by up to 6,000 ash trees, although a third of the wood is oak.

The trust said another similar but much smaller plantation nearby, which contains a few hundred trees, also appeared to have the disease.

A spokesman for the National Trust said the Blackford trees had been planted around 12 years ago.

He said further investigations would be carried out before the trust decided what action would be taken to try and prevent the disease spreading.

Usually, infected trees and vast swathes of healthy trees around them have to be felled to try and contain the airborne fungal spores.

"Finding the disease at this site is alarming as it is over a 150 miles from the main area of the disease in the east of England.

"The trees are also much older than most other trees found to be infected and we are not sure how long they have had the disease.

"We have been looking at other trees around this site and so far have only found it in one other nearby plantation.

"So whilst we are worried, there is a glimmer of hope that this disease may not be spreading out from infected sites as fast as we feared," the spokesman said.

It is the second confirmed case of the potentially devastating disease in the West Somerset area after a newly planted young tree was found to have the fungus in the Nether Stowey area in November last year.

At the time, Defra said the infected sapling was likely to have been part of a batch of trees planted on private land and not infected by airborne disease spores.

Experts fear the disease could all but wipe out the UK's 80 million ash trees.

Defra said Somerset was now one of 15 counties in England where Chalara had been discovered in forests and woodland.

Martin Ward, Defra's chief plant health officer, said: "We expected to see new cases once the leaves came through on ash trees.

"The better informed we are, the more effective we can be in our work to reduce the impact of this disease and we will be investigating this new case closely."

The ash tree is a native British species of tree, providing around five percent of all woodland cover.

Chalara has already affected a high proportion of ash trees in northern Europe and was confirmed in the UK in early 2012.