Nature enthusiasts, walkers and gardeners are being asked to keep watch on their local ash trees for signs of a new disease.

Ash dieback disease, caused by the fungus Chalara fraxinea, was found in the UK for the first time earlier this year and residents should report any suspected cases as quickly as possible.

Although the disease has not yet been found in the wild, with known infected trees being young ash plants in tree nurseries and recently planted sites, the fungus spores are carried in the wind and so the chance of the disease spreading is high.

Symptoms include the premature loss of leaves from the outer parts of the crown (top and sides) and long diamond-shaped lesions or areas of sunken and discoloured bark on twigs.

These lesions girdle twigs and small branches, starving the leaves above of water and nutrients and causing whole branches to die. In mature trees, it is the new growth that is affected.

Dorset County Council arboricultural manager Steve Maros said: “We’re asking residents to be vigilant for signs of the disease and report any ash tree they suspect has been infected. Obviously it will be difficult to spot at this time of year and is more likely to be identified in the spring when the trees should come into leaf.

“It’s important that people are aware of ash dieback, which is now one of many pests and diseases that pose a threat to our native woods and trees, but there is currently no need for the preventative destruction of ash trees.

“There is also no reason that some ash trees can’t continue to be planted as some varieties are more tolerant of the infection – but residents should buy from a local, reputable retailer and ensure that the tree hasn’t come from a site where the disease has already been found.”

Further information about ash dieback disease and details of who to contact in the event of a suspected case can be found at www.dorsetforyou.com/ash-dieback-disease