Ash dieback (Chalara fraxinea) has been a hot topic in the news recently. And for very good reason. The disease has already spread through much of central Europe and now threatens Britain's 80 million ash trees. We asked Charles Notcutt for his thoughts on the disease:
Ash die back disease is caused by a fungus, Chalara fraxinea, which has now been shown to be the asexual stage of the fungus Hymenoscyphus pseudoalbidus. The disease was first seen in Poland in 1992 and has spread through the majority of Ash trees in Denmark and Sweden, and as far south as Belgium on mainland Europe. The spores of the fungus have been blown over the North Sea. As a result, the infection has been identified along the east side of England and suspected on the east coast of Scotland.
The disease has been found on young trees and coppiced Ash, but it is probably in mature woodlands on foliage high up on the trees, where it is difficult to identify it.
The disease has been in this country for several years, but Government recognition and action on this has only recently occurred. Sadly, it will not now be possible to eradicate this disease. The fungus grows in the summer on fallen Ash leaf litter, so the best recommendation is to remove this from under any Ash tree and ensure the leaf litter is destroyed. This may help to reduce local spread.
The longterm solution lies in locating strains of mature Ash trees which show some genetic resistance to the disease, so could therefore be used for propagation and replanting of woodlands. The recommendation is, therefore, not to fell mature trees until any resistance to the disease has been assessed, but the leaf litter should be removed.
Information on Chalara fraxinea, how to identify the disease and detail of confirmed cases of new plantings in the wider environment can be found at www.forestry.gov.uk/chalara
If infection is suspected it is recommended that contact is made with the Forestry Commission Plant Health Service, either by phoning 0131 3146 414 or e-mailing them at [email protected]. Contact can also be made through the University of East Anglia’s (UEA) website http://www.ashtag.org. If a photo of suspect foliage is sent to UEA their expert panel will assess and advise.
What else can I do? Where can I find more information?
- Questions about Ash dieback? The Guardian has a really helpful FAQs quide
- The Forestry Commission has produced a handy 'How to spot' guide. Download here.
- Visit ashtag.org to view videos and latest photo reports - you can also upload a suspected sighting
The Forestry Commission has had an overwhelming response to their request for updates. They have asked that people keep up the great work, reporting suspected cases so they can investigate. Tip tip - now that leaves have dropped, look for the characteristic lesions or dieback, rather than for leaf symptoms.
