Deadly fungus ravages Britain′s forests | Environment| All topics from climate change to conservation | DW | 12.12.2012
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Deadly fungus ravages Britain's forests

Chalara fraxinea fungus has infected woodlands across Britain, devastating the country's ash trees. Officials have imposed an import ban but experts say Britain's 80 million ash trees remain at risk.

Hundreds of reports of ash dieback are pouring in from across Britain. Officials have now confirmed new infections in a woodland nature reserve in Cambridgeshire.

"Experts fear it is the greatest threat to British trees since 25 million trees were killed by Dutch Elm disease 30 years ago," said Mary Creagh, the Labour Party's shadow environment secretary, in an interview with DW.

Ash dieback is caused by the fungus Chalara fraxinea. It attacks the crown of ash trees, causing lesions and wilting - eventually killing the tree off. It was first discovered in Eastern Europe twenty years ago. Now, experts fear it will wipe out Britain's 80 million ash trees.

In response to the crisis, the government has imposed a ban on ash imports and the movement of trees from areas with confirmed cases.

Too little, too late

The Chalara fraxinea fungus is known to spread quickly and kill almost every ash tree it comes into contact with. Robert Crowder, owner of Crowders Nurseries in England's northwest, says the government had plenty of warning.

Ash tree disease. A general view of a young Common Ash Tree with wilting leaves in woodland near Canterbury, Kent, which shows the symptoms of the deadly plant pathogen fungus Chalara Fraxinea Dieback. Picture date: Wednesday November 14, 2012. Photo credit should read: Gareth Fuller/PA Wire URN:15124755

In the early stages of ash dieback the infected tree's stems and leaves turn brown

"In 2009, representatives of the nursery industry, the tree growers in the UK, warned the government that this fungal disease was rife throughout Europe," Crowder told DW. "We said to the government that if you don't do something to stop these trees coming into our country, we're going to have a major problem."

Three years later, Crowder's Nursery was forced to destroy 50,000 ash trees. Crowder says his nursery became infected when they ordered what they thought were domestic trees. The trees had in fact been grown in Germany, where the disease has existed for several years. Crowder believes this wouldn't have happened if the government had banned imports earlier.

"Now, it's too late, the disease has spread right across the country. Every week we're hearing of more cases and the problem is now too big to deal with or contain," he said.

Britain's Environment Secretary Owen Paterson has been facing tough questions about the government's failure to stop ash tree imports in time to prevent the current situation. The politician confirmed that officials still don't have a solution to offer.

"This may have very serious consequences. At the moment we don't have a cure." said Paterson.

Building resistance

One solution may be found just across the North Sea in Denmark, where a battle against ash dieback has been carried out for more than a decade. Professor Erik Kjaer, from the University of Copenhagen, says Britain should focus on finding surviving trees with natural immunity.

"Some of the trees seem not to suffer from the disease," said Kjaer. "Not many, maybe a few percent, seem to have some kind of natural resistance, and that means that even though they're infected, they maintain their health and continue growing.”

Professor Kjaer says time is of the essence. If Britain starts working on building up a new and resistant generation of ash trees, it will still take more than a decade for a healthy population to establish itself.

According to Britain's Forestry Commission, the trees are facing an 'unprecedented level of threat' from all sorts of pests and diseases. Peter Heldane is the Wildlife and Conservation Officer for Wimbledon and Putney Commons and says he has to plan ahead to outwit the next tree disease.

***Achtung: SCHLECHTE Qualität - nicht als Teaser- oder Karusselbild verwenden!*** Ash tree in Great Britian with Peter Heldane Wer hat das Bild gemacht/Fotograf?: Anja Kueppers-McKinnon Wann wurde das Bild gemacht?: November 2012 Wo wurde das Bild aufgenommen?: Wimbledon Common in southwest London Bildbeschreibung: Bei welcher Gelegenheit / in welcher Situation wurde das Bild aufgenommen? Wer oder was ist auf dem Bild zu sehen? Ash tree in Great Britian

Peter Heldane grew up near Wimbledon Common and has seen the woods change over the years

"If one variety is being hit by disease, and you want to replace it, you want to be sure that the species you're replacing it with isn't going to be attacked just down the road as well," Heldane told DW in an interview. "You want to know that it's going to have the best chance to survive."

For 12 years, Heldane has been working on Wimbledon Common in southwest London - about 460 hectares of woods and green space. He knows first-hand the devastating effect tree diseases can have.

"When you come to the Common for a nice walk and to enjoy the scenery, you just take it for granted," said Heldane. "This shows how quick not just the environment, the lovely place you come to play in, can disappear."

Environment Secretary Owen Paterson had announced the government's action plan to tackle the disease. Inspectors will focus on slowing the disease's spread through the countryside, by destroying young, diseased trees. They hope the public will take an interest too and will be offering education classes in rural areas.

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