pScientists are warning that an outbreak of a deadly tree disease could devastate Britain's entire population of ash trees which make up 30 percent of the UK's woodlands.pbr pAsh dieback has now been identified in 115 sites and that number is rapidly rising as more and more infected areas are being discovered.pbr pPound Farm, a woodland in Suffolk, south-east England, where the disease in the wild was first confirmed, now displays signs warning walkers to be careful not to spread the fungus on their boots.pbr p"All the ash trees are beginning to dieback, so that generally means that the ash is becoming sickly and slowly but surely beginning to die in the wood," said Mike Ryder, who manages the site for the charity the Woodland Trust.pbr pDieback is caused by the Chalara fraxinea fungus.pbr pIt mutated into a deadly strain in Poland in 1992 and has now infected up to 90 percent of ash trees across the continent.pbr pAt first it was thought dieback arrived in the UK via young trees imported by nurseries from Europe.pbr pBut the presence of it in mature trees in ancient woodlands leads experts to think the airborne disease could have been blown across the sea.pbr pRyder said the fungus will likely devastate Briton's landscape.pbr p"In [continental] Europe potentially 90 percent of the ash trees have died off. Within this country it will significantly change not just our ancient woodlands but other woodlands in there, so our whole landscape could be changed."pbr pAt the end of October the government introduced a ban on imports and the movement of trees from areas with confirmed cases of dieback.pbr pHorticultural trades groups have criticised th handling of the crisis, saying ministers were first alerted to the threat in 2009.pbr pOne nursery forced to destroy 50,000 ash trees is considering suing the government for not blocking imports from Europe years ago.pbr pRyder said the authorities need to take bio-security more seriously.pbr p"What would be good for the government to actually begin to tighten up our imports of planted stock. Some sort of plant passport so we know exactly where everything has come from, so if it is infected it can be traced back very, very quickly back to the infected nursery instead of spending time actually trying to find exactly where it has come from," he said.pbr pIn the last fortnight the Forestry Commission, a government body, sent a team of 500 specialists across the UK to inspect oak trees for a rapid reaction survey. Lab tests won't be available for around a week.pbr pIn London's ancient Highgate Woods, Forestry Commission's Jim Smith did not find any cases of ash dieback, but that could change.pbr pHe said the government was taking the issue very seriously, worrying it could be as bad as the Dutch elm disease epidemic in Britain in the 1970's which blighted the country.pbr p"You only have to see the speed with which government has reacted that it is being taken very, very seriously. Everyone is talking about this in terms of a second Dutch Elm disease because if you look at the experience on the continent, it is a serious problem for ash trees and that is why we are taking it very seriously indeed," he said.pbr pThe loss of some 80 million ash trees will have an impact on nature, the landscape and businesses which use ash wood.pbr p"There are two issues: One is the loss of a very important economic tree for the UK, ash in terms of timber product, but also in terms of bio-diversity, and also we shouldn't forget the landscape in terms of thepbr pamenities that the mature trees provide, as did the Dutch elm trees in the past. So we are looking at the loss of a whole spectrum of benefits that that particular species of tree give us."pbr pAn emergency summit on Wednesday (November 7) discussed what can be done to prevent the spread.pbr pThere is no cure for dieback and until the full extent of the infection is known it hasn't been decided whether the best course of action is to cull trees, contain woodlands or what products and plants to ban from import.pbr pThe disease will naturally have a huge impact on ash timber merchants and trades which rely on the species, but it also threatens Britain's medieval heritage.pbr pIn a rural Surrey, near London, Carol Pearce makes traditional arrows for use in primitive archery, a popular sport for fans of the legend of Robin Hood.pbr pHer business could be ruined if she can't get hold of ash and use woodland to teach in.pbr p"The ash bows that we use for doing primitive style of shooting and traditional style of shooting, if we can no longer get them it will put several people out of work and will affect me especially if you can't go into woodland, because most of my arrows are used for field archery which is of course woodland archery, if that stops that will be the end of the business," she said.pbr pShe's angry with the government for not protecting Britain's ash trees years ago.pbr pAn indigenous tree, the ash has always been used for traditional bows and arrows.pbr pShe can make modern arrows out of other types of wood, but says it would be a shame to see tradition killed off with the ash tree.pbr p"It is really nice to keep something of the traditions going, a bit like thatching I think, if we lose that I think we lose part of our heritage.