Ash Dieback Disease
Ash Dieback Disease (ADD), also known as Chalara Dieback of Ash, is a fungal disease that affects all species of ash tree (Fraxinus).
Ash Dieback Disease
It is the most significant tree disease to affect the UK since Dutch Elm Disease. In Britain, the disease was first officially recorded in south-east England in 2012 from where it has spread west across the UK. It is now affecting most parts of Scotland.
The fungus (Hymenoscyphus fraxineus) attaches itself to the leaves of ash trees and spreads through the branches where it blocks the water transport systems, causing leaf loss, lesions in the wood and on the bark. This leads to the gradual dieback of the tree crown. Trees become brittle, with branches breaking off or the whole tree failing. If they are not managed appropriately, trees are at risk of collapsing, presenting an immediate danger to the surrounding area.
There is no known cure or practical way to prevent the disease from spreading. It is likely that we are likely to lose at least 50-75% of Scotland's 11 million Ash trees over the next 20 years.
Ash dieback affects the leaves of ash trees causing them to blacken, wilt and die from around June onwards. For very young trees this and the diamond shaped lesions (areas of discoloured bark) on the stem are the key features of early infection. It appears that most of the young ash trees in West Lothian are already significantly affected by this disease.
As the name suggests, the disease causes the tree to die back from the edge of its canopy. In mature trees, the first sign of the disease is bare, dead twigs at the top of the tree and ends of the branches. As the disease progresses and the number and length of dead branches increases, the tree responds by growing new leaves closer to the main branches and trunk giving the tree a clumpy 'pom-pom' look. Eventually the tree will look increasingly bare and dead.
Ash is a species which is late in coming into leaf and so the best time to check for symptoms is from mid-June to August.
Ash dieback can also lead to serious discolouration, cracking and death of the bark at the base of the trunk.
For further information on how to recognise ash dieback, can be found in the references section below.
There are thousands of ash trees on public land in West Lothian and many more on private land. Ash is one of the most common, native tree species in the area, and it contributes significantly to the local landscape and ecology.
Remedial felling and pruning
West Lothian Council will only be dealing with trees on public land, such as parks, schools, or within roadside verges that it owns and/or manages.
The council also has a duty of care to protect the public from dangerous trees on private land that have the potential to impact public areas such as highways. The council has started to survey trees along its road network and plans are being made to provide information to householders and landowners who may have trees with Ash Dieback Disease within falling distance of roads, well-used paths and other areas well-used by the public or themselves.
The council committed a budget for the previous financial year to undertake surveys and some initial remedial work, which in turn will help staff plan for more widespread work over the coming years. Residents of West Lothian already may be aware of work being undertaken, by contractors, to remove or make trees safe along the road network.
Where possible the aim will be to undertake work in a planned and efficient manner to deal with all the seriously diseased trees in a whole section of road at a time rather than having multiple road closures. It is hoped that local landowners will work with the council to allow this work to be undertaken in a co-ordinated and, more importantly, safe manner!
It is also important to look out for trees with little or no symptoms. These trees may have high levels of resistance to the disease and should not be considered for removal; these trees are very important for the ecological value they retain in the environment and they may help repopulate the species in the future.
Trees affected by Ash Dieback Disease can provide a very important habitat for fungi and invertebrates, which feed on the decaying wood, and in turn birds which feed on them. Other creatures such as mice and bats make their home in them. Consideration should be given to retaining these declining trees, wherever it is safe to do so.
Where trees are removed on safety grounds by the council, new trees of another suitable species will be replanted. This will be either in the same location or in a nearby one, so that the treed landscape across the whole council area is enhanced in the long-term.
Trees play a really important part in how areas of West Lothian look and feel. They also provide habitats for all sorts of other species, as described above, and help combat climate change by their ability to capture carbon dioxide from the air and convert it into wood. Recent research has confirmed what many always knew that being close to tree cover also improves human health.
A guide for tree owners in Scotland is due to be published on the Tree Council's website.
Inspect your trees
The first thing to do is to check tree/s in your garden or on your land between mid-June and end of August. You can use the photos given in the Ash Dieback Toolkit for Scotland or the Tree Owners Guide (England and Wales), links given in the "Further information" section or seek the advice from a qualified arboriculturalist.
Consider Appropriate Action
If the trees are located well away from roads, paths, buildings and other places which are well-used by the public or yourselves. Please consider leaving them to decline naturally and thereby creating a habitat for all sorts of plants and creatures.
Where the tree/s stand within falling distance of public roads, well-used public paths, buildings etc, you are responsible for its safety.
Staff from West Lothian Council have started inspecting trees, including those on private land, along public roads. In some instances, the council would like to work with landowners to co-ordinate remedial work, where these trees are in a condition likely pose a risk to road, path or other users. This would reduce the number of times roads have to be closed and traffic diverted, for the work to be done safely.
So that the council can contact you, we will shortly have an on-line form.
We are sorry but we are unable to advise tree owners on their trees.
NB if the tree is in a very poor condition you should take prompt action and not await the council's programme.
Where the affected tree is within falling distance of an area well-used by yourself, family, staff and / or visitors you are advised to undertake action to reduce the canopy or fell the tree to make it safe.
Trees affected by Ash Dieback Disease become brittle and can be very unpredictable and dangerous to climb, prune or fell. Those showing advanced dieback symptoms should not be climbed.
Work should only be undertaken by qualified and experienced arborists (tree surgeons) and, wherever possible, by mechanised means or from a mobile elevation working platform (MEWP).
You need to ensure that anyone engaged to undertake this potentially dangerous work is fully insured and has the appropriate training, qualifications and experience.
Where trees are within falling distance of public roads or core paths, traffic management, in some cases including road closures, will be required - Road Permits and TTROs
The tree and surrounding area needs to be checked for the presence of protected species such as badgers, bats and nesting birds if work is being undertaken during the breeding season.
From sample surveys conducted in areas where failing ash trees are likely to pose the most risk, a conservative estimate of the extent of Ash Dieback Disease is as follows :-
|Location||No of trees in poor condition with < 50% of crown remaining||No of trees showing symptoms but with > 50% crown still remaining|
Council owned / managed trees along roads, main paths, school grounds, public openspace
|Trees on private land within falling distance of roads||>2050||>3800|
The population of ash trees in these areas tends to be mainly semi-mature trees with only a small proportion of large, mature trees but nevertheless will deplete the landscape of important features both now and in the future.
There are many more ash trees in woodland areas, especially young ones, which have also succumbed to Ash Dieback Disease.
It is the Council's intention, as funding allows, to replant trees which have to be removed with suitable alternative species, in the same location where possible. It will also be encouraging private tree owners to do likewise.
Please note that the legal system and regulatory authorities in Scotland are different to those in England and Wales.
The management of trees normally lies with the owner of the land on which they stand. Landowners have a legal "duty of care" to ensure that, as far as is reasonably practical, public safety is not compromised by the failure of branches or a whole tree which has known defects.
For further information please see "Common sense management of tree safety", a link to which is given in the reference section below.
In some instances, Felling Permission will be required from Scottish Forestry. Please see the links, in the Reference Section, to their documents on felling individual trees and within woodlands on their website.
If your tree is the subject of a Tree Preservation Order this should be recorded on your deeds but it is a good idea to check with the council's planners. Most TPOs cover individual or groups of trees but it should be noted that there is a large, area wide TPO covering many of the mature trees in the south of Livingston.
Prior to undertaking any pruning or felling work on a tree covered by a TPO, an application must be made to West Lothian Council - Tree Works.
Prior to undertaking any work on trees within a Conservation Area you must give the council at least 6 weeks' notice - Tree Works.
Further information, useful links and websites
Identifying Ash Trees - Identify trees with our Tree ID app - Woodland Trust
Recognising the symptoms - Chalara Dieback of Ash. You can also report sightings of any tree pests and diseases through Observatree
Management of Trees affected by Ash Dieback - Ash Dieback Toolkit for Scotland - The Tree Council
West Lothian Council's Draft Action Plan - Ash Dieback Disease – West Lothian Council’s Draft Action Plan
Advice for householders and landowners regarding trees affected by ADD on their land - Tree Council - Ash Dieback Tree Owners Guide. This guide was prepared for England and Wales in 2020 a similar guide for Scotland including the appropriate legal guidance and organisational contacts is due to be published.
- Tree Safety and Landowner's Duty of Care - Tree Safety and Landowner’s Duty of Care. Useful information is given in the national Tree Safety Group's -Common sense management of tree safety.
- Felling Permissions - Scottish Forestry - Ash dieback in Scotland. Management of individual trees affected by ADD in Scotland and Management of woodlands affected by ADD in Scotland.
- Tree Preservation Orders (TPOs) and Trees in Conservation Areas. If you are wishing to undertake any pruning or felling of trees which are the subject of a TPO or lie within a Conservation Area please contact - Tree Works
- Wildlife Legislation - Species such as badgers and bats are protected and may require a licence for work to be undertaken with the supervision of a trained ecologist - Wildlife Legislation - European Protected Species. It is also an offence to disturb nesting birds. The breeding season in Scotland, for most birds, is considered to be from beginning of March to end August.
Information for Tree Surgeons and others undertaking tree work is given in the Arboricultural Association Practice Guide. Link is given in the reference section.
Guidance for woodland managers and operators is also given on the Forest Industry Safety Accord (FISA) website
Link to the on-line information and forms for applying for a road / path closure or traffic lights