Ash Dieback Update.
The majority of the UK are now becoming aware of Ash Dieback and its impact on the population of Ash trees across the country.
As we increase the amount of inspections and remedial work to help control this disease, we have prepared some information for our clients and stakeholders to keep them up to date.
About Ash Dieback
Ash dieback is fungal disease affecting the common ash tree (Fraxinus excelsior) and other Fraxinus species. It is caused by a fungus called Hymenoscyphus fraxineus which is native to eastern Asia. The disease was first identified in England in 2012, although research has shown that it is likely to have been present since at least 2005.
The trees make up 12% of Great Britain’s broadleaved woodland, and are often found in parks, gardens, hedgerows and roadside margins. It has the potential to infect more than two billion Ash trees.
Identifying ash dieback
Infection can lead to leaf loss and dead branches throughout the crown of ash trees, and clumps of new growth towards the centre of the crown.
In areas of high infection, the fungus can cause lesions at the base of the tree, making it more susceptible to secondary infections, such as by Armillaria fungi.
Management options
There is currently no cure for chalara ash dieback, and no clear method for stopping its spread. Therefore the aim of management, as outlined in the National Chalara Management Plan, should be to slow the spread, minimise the impact of the disease, and preserve as many chalara-tolerant ash trees as possible.
Managing the safety risk from dead and dying trees
Public safety is likely to be one the biggest management issues for owners of ash trees in woodlands and parks and alongside roads, railways, footpaths and carparks etc as the disease kills or weakens trees.
Trees in areas with high levels of public access therefore need to be monitored carefully for risks to public safety, and some felling or pruning of dead or dying trees is advisable if risk assessments show they are a hazard.
When assessing trees’ health, we look for signs of lesions (cankers) or honey fungus (Armillaria) near the base of the trunks: these can weaken the trunks and make the trees more prone to falling.
The felling of dead and dying Ash in effect makes an already hazardous operation much more dangerous, it is essential that every effort is made to fell these sites mechanically and to keep any chainsaw operations to an absolute minimum.
The increase in crown deadwood dramatically increases the risk of an operator being hit by falling branches and tops.
Additionally, as a company we ensure that risk assessments and method statements are effectively communicated to all operators and that only the most competent and well equipped operators are used on sites where dead Ash is prevalent.
It may be necessary to apply for and obtain a felling licence well-ahead of felling diseased trees that occur along roadsides or in other high risk situations. Some felling licences may take longer to obtain if trees are subject to environmental legislation and protection e.g. a Tree Preservation Order.
DON’T wait for a felling licence if trees along a highways are dangerous. Such trees are exempt from requiring a felling licence. Instead focus on arranging any necessary highway /rights of way closures and contractors to undertake the work safely and without delay.
Record if possible the reasons for classifying it as dangerous e.g. photos of rot, splits etc. If in doubt contact your local District Council’s local Woodland Officer.
We hope you found this information useful, if you would like further details then there are a number of websites to research as below:
Arboricultural Association The Tree Council FISA Forest Research Gov.uk
As always, we are also on hand for help and advice as well as undertaking remedial works, please click here to contact us.
