Chalara dieback of ash is a serious disease of ash trees caused by a fungus called Chalara fraxinea (C. fraxinea).
The disease causes leaf loss and crown dieback in affected trees, and it can lead to tree death.
Ash trees suffering from symptoms likely to be caused by C. fraxinea have been found widely across Europe. These have included forest trees, trees in urban areas such as parks and gardens, and also young trees in nurseries.
C. fraxinea is being treated as a quarantine pest under national emergency measures, and it is important that suspected cases of the disease are reported.
Update 5 November 2012
In response to the Forestry Commission announcement that Chalara ash dieback has been found in the woods and hedgerows of East Anglia, we can confirm that the disease has been found in both the mature ancient woodland and woodland creation areas on our estate at Pound Farm in Suffolk. We are currently carrying out further investigations at other sites.
The Department for Forestry and Rural Affairs (Defra) has released a statement confirming the ban on import and movement of ash trees to combat the threat of the tree disease Chalara.
The government is now holding a summit this Wednesday 7 November and the Trust is calling for priority to be given to the protection and safeguarding of our natural woodland resources.
We need to make woodland and the environment a priority, and create a political and economic environment that will enable the sustainability of vibrant woodland habitats across the UK. Find out how you can help us.
Furthermore we need Government scientists to give urgent and clear advice to all woodland owners on how to manage the disease. We will do all it can to mitigate spread in line with Government instructions and advice.
What should I do if I think I have seen a tree with ash dieback?
Please report any sightings at once. The disease is most likely to be found in newly planted young trees. Contact details are shown on the right hand side.
In February 2012 it was found in a consignment of infected trees sent from a nursery in the Netherlands to a nursery in Buckinghamshire, England. In June 2012 it was found in ash trees planted at a car park in Leicestershire which had been supplied by a nursery in Lincolnshire, and the origins of the disease in this case are being investigated. In July 2012 the Food & Environment Research Agency (Fera) confirmed cases in the nursery trade in West and South Yorkshire and Surrey, and by September 2012 it had been reported in a nursery in Cambridgeshire.
It has also been found at four recently planted sites - a Forestry Commission Scotland woodland at Knockmountain, near Kilmacolm, west of Glasgow; the car park in Leicester, a college campus in South Yorkshire, and a property in County Durham.