A MAJOR survey has begun across the New Forest to discover if ash trees have been infected with a deadly disease sweeping the country’s tree population.

The Forestry Commission has said it will start the research to determine how many of the at-risk trees there are and whether the killer fungus has already taken hold.

In the last week the number of sites nationally found to be infected with ash dieback disease – which threatens to wipe out the ash population – has doubled, with more than 100 locations recording outbreaks.

In Denmark the disease, officially known as Chalara Fraxinea, wiped out 90 per cent of the ash population.

The fungus has become so widespread that environment secretary Owen Patterson urged the public to wash boots, dogs and even children to halt the spread.

Andy Paige, head keeper for wildlife in the New Forest, said: “We need to find out the extent of the damage, if any, in the New Forest. We’re going to begin a survey to find out how many ash trees there are and how many could be affected. At the moment the situation is quite new but it’s evolving day by day.”

There are estimated to be 80 million ash trees in the UK, with each one growing up to 40 metres tall and living for up to 150 years Ash dieback can be spread on the wind. The disease causes leaf loss and kills the crown of affected trees, and it can lead to tree death The fungus was first reported as an unknown new disease in Poland in 1992 and since then has caused widespread damage in Europe The Forestry Commission says the risk of visitors spreading the disease is small so they are not closing forests. But they are asking visitors to take simple precautions by not removing any plant material from the woodland and cleaning soil, mud and leaves from footwear, bicycle wheels and tyres.