12 December 2012 Last updated at 08:18 ET

Ash dieback at ancient woodland in Cambridgeshire

The first case of ash dieback disease in an ancient woodland nature reserve in Cambridgeshire has been reported.

The case of Chalara fraxinea fungus has been reported at the Wildlife Trust's reserve at Gamlingay Wood.

The trust said the reserve would remain open but it asked the public to check their footwear on leaving and remove any organic matter.

Wildlife Trust's director of living landscapes, Chris Gerrard, said: "This is sad but not unexpected news."

He added: "Ash dieback has been recorded in over 300 sites across the country so I feel it was only a matter of time before it was found in one of our reserves.

"Gamlingay Wood is a wonderful place for wildlife and people and we are determined that it will continue to be so despite the impacts of the disease."

Symptoms of Chalara dieback

• Diseased saplings typically display dead tops and side shoots
• Lesions often found at base of dead side shoots
• Lesions on branch or stem can cause wilting of foliage above
• Disease affects mature trees by killing off new growth

• How to spot the signs

A trust spokeswoman said it was thought the only other cases in Cambridgeshire of diseased trees had been newly planted saplings on the side of a road.

The disease, which affects ash trees, was first confirmed in the UK in March. Since then 65 established woodlands have been affected.

The government has imposed an import ban on ash trees and a nationwide survey is being carried out to find out how far the disease has spread.

It is also hoped scientists will find a natural resistance within the UK's population of ash trees which will make the next generation resilient.

Britain has 80 million ash trees which cover about 5% of all woodland and provide food and shelter for birds and more than 100 types of insect.