Ash Die Back Disease (Chalara) Source EPPO (European and Mediterranean Plant Protection Organisation)
Ash die back disease is a serious problem that has received prominent attention in the media recently. It is likely to have a devastating impact on the 3rd most common species of tree in Britain and a subsequent impact on biodiversity and the landscape. Creative Landscape Design are monitoring news about the spread of disease will pleased to provide an initial free consultation if landowners or gardeners in Thame, Aylesbury or Oxoford area who have any concerns about their trees and provide ongoing advice on how to manage the impact as well as producing a strategy to replaced lost woodland or trees.
Ash die back disease (the Chalara fungus infection) has arrived and is killing ash trees (Fraxinus excelsior) in Britain. The disease causes infected trees to die back and is thought to have killed 90% of the trees in Denmark. COBRA held a crisis meeting and it would seem that the disease is now at large in the countryside. Britain will probably lose most if it’s ash trees.
The English elm was also devastated by Dutch Elm Disease in the 1970’s. I remember seeing large areas of our local woodland clear felled in an attempt to halt the spread this disease that was carried by a beetle. Will the same fate happen to all our ash trees?
There are some important differences. On the negative side: Ash Die Back disease is thought to be wind spread. There are confirmed out breaks in Wales and central England, so the spores are likely to spread no matter what. Ash trees tend to breed from seed where as elm trees tend to renew by vegetative reproduction and re-grow from their stump. This disease will kill and ash tree completely but ash are more genetically diverse, so there is a greater chance of individual trees becoming resistant to the fungus, serving and repopulating the countryside (all be it in a couple of centauries). The elm keeps making a comeback until it reaches a size where the beetle can find it.
The disease is probably going to have a devastating impact on our landscape and wildlife in teh short to medium term. So what strategy should landowners and gardeners adopt?
The Forestry Commission and other bodies are currently trying to find out how far the disease has spread. At the time of writing there are now hundreds of infected sites. There are confirmed cases in Bicester, Leyton Buzzard and Milton Keynes (the disease was first reported at a nursery in Buckinghamshire). It is quite possible that the disease will spread to Thame in and Aylesbury Vale in the near future.
Vigilance is needed especially in recently planted trees. There are spotting guides available at http://www.forestry.gov.uk/chalara and http://www.bbc.co.uk/news/science-environment-20171524 .
The import ban on new ash trees would appear to be too late. The Landscape institute has advised that no further plating of any kind of ash. Existing contracts may have to be renegotiated and replacement species found. Spread can be minimised by avoiding transport of ash leaf litter- compost or dispose of on site, avoiding transport of logs from site to site. This will slow the spread, but cannot prevent distribution of the disease by windblown spores.
Clear felling of large areas of woods to create a ‘fire break’ seems very unlikely to work (and was an abject failure in the case of Dutch elm disease) and comments from various conservation groups suggest that the action plan will not include such draconian measures. Besides all the material would need to be destroyed and the roots grubbed up to remove all of the infection since symptoms include bracket as basal fruiting bodies It may make sense to remove recently planted trees or young saplings. The emphasis may be to breed or encourage resistance and removing otherwise healthy trees that may be counterproductive and mature trees to live as long as possible providing a habitat for a host of wildlife until a new resistant generation of ash trees provides new homes.
Landowners will need to monitor trees that are growing near buildings, highways, paths and other areas for safety to ensure that risk from falling deadwood or trees are minimised. It would be wise to start to make some budget provisions for increased tree works.
Finally, landowners may wish to restock woodlands and replace feature trees with suitable specimens. A feature tree could be replaced with a semi mature specimen. Woodlands could be restocked with saplings of native trees. Given the course of recent events, it might be wise to source locally produced stock from the UK!
Whatever your concerns about managing your land or dealing with issues like ash dieback disease Creative Landscape Design are here to help!