Experts in TREE PESTS & DISEASES
Ash Dieback causes a range of symptoms from foliar leaf spots to branch dieback and the death of ash trees. Once infected, most trees will die. A few ash trees may survive the infection because of genetic factors which give them tolerance to the disease. Trees should only therefore be felled where they pose a safety risk.
Trees infected with Ash Dieback can be dangerous and technically challenging to deal with. The disease can render trees unstable and prone to failure of branches and whole trees. Predicting how a particular tree will behave is impossible. It is usually not possible to employ standard climbing and dismantling techniques due to the danger posed to the arborist.
If you need advise on Ash Dieback please contact us today.
Here at, Thompson Tree Services, we have a lot of experience in the identification, management and mitigation of the effects of Ash dieback. We can help you to identify Ash dieback in your trees, assess the potential impacts of the disease on your particular situation and help develop and implement action plans for dealing with the effects.
Our consultants are able to survey your tree stock with speed and precision, allowing us to identify the presence of the disease in your Ash trees and the current condition of those trees. We can then undertake a risk assessment that will help to identify unreasonable levels of risk across your tree stock and enable you to make more effective use of your budget to address high risk situations as a matter of priority. Using this information, we can help you to develop prioritised work schedules aimed at reducing your potential liabilities.
Trees infected with Ash dieback can be dangerous and technically challenging to deal with. The disease can render trees unstable and prone to failure of branches and whole trees. It is often not possible to employ standard climbing and dismantling techniques due to the danger to the climber. Thompson Tree Services have a large range of specialist equipment including an articulated crawler crane with grapple saw, Mobile Elevated Work Platforms and Tree Shears to enable the safe removal of affected trees. We have developed and recorded specific methods and risk assessments to ensure that dangerous trees can be safely removed with minimal risk to skilled staff, members of the public and property.
The loss of Ash in our region and nationally is likely to impact heavily on landscape quality, wildlife dependent on trees, the volume of storm run-off and the summer temperatures of cities and towns. Its loss will also have an impact on soil composition, specialist lichen communities and broadleaved timber products in woodlands. Thompson Tree Services can help you to mitigatethe loss of Ash trees in several ways:
Health and safety impacts
Quite simply you need to make a plan. Ash dieback is either already in an area or is likely to be in the next few years with potentially serious practical and financial impacts to many individuals and organisations. Ash dieback will lead to changes to our landscape and tree populations, changes to biodiversity and landscape character, and potentially increase effects such as flooding caused by the way water interacts with the environment. The national cost of removing trees with Ash dieback is difficult to calculate but the scale of health and safety risks caused by Ash dieback alone will require significant investment and mean that it will not be ‘business as usual’ for any organisation managing Ash trees. Tree failures could translate into an increase in the number of people harmed by trees and a potential increase in property claims. Organisations and individuals will need to review and, where necessary, make changes to tree safety management regimes and practices. Planning a logical, consistent and robust response to Ash dieback should be built on the following steps:
Ash dieback is the most significant tree disease to affect the UK since Dutch elm disease, which claimed 30 million British elms. Ash dieback has the potential to affect more than 150 million mature trees across the country with many more millions of saplings and seedlings also being impacted. It is estimated that there are up to 60 million ash trees outside woodlands in the UK. The percentage of the UK’s ash trees that are likely to be tolerant to the fungus is still unknown. However, evidence from Europe suggests that 10% of trees will be found to be moderately resistant to the disease, with 1-2% having high levels of tolerance. Individual ash trees will respond to the disease in different ways depending not only on their genetic make-up, but also on their age, location, management practices on site, soil type and levels of secondary pathogens present such as honey fungus. (Tree Council)
Sometimes known as ‘Chalara’, Ash dieback affects Ash and other Fraxinus species of trees and is caused by a fungal pathogen. The fungus, Hymenoscyphus fraxineus (anamorph - Chalara fraxinea), is believed to have originated in Asia and was discovered in Europe during the 1990s since which time it has rapidly spread across the continent. It was first officially recorded in the UK in 2012, although evidence now suggests it arrived here as early as 2004.
This invasive fungus causes a range of symptoms from foliar leaf spots to branch dieback to the death of Fraxinus excelsior (Ash) trees and some other Fraxinus species. Once infected, most trees will die. A few ash trees may survive the infection because of genetic factors which give them tolerance to the disease.
The precise speed of decline of any individual tree is currently impossible to predict and will be influenced by other factors including soil type, soil moisture levels and topography. However, in some cases, the decline from infection to a potentially dangerous state can be rapid, sometimes in a matter of 2-3 years. Where basal lesions are observed, these can develop into a butt or root rot and the affected trees can become unstable and dangerous very quickly. The rot is usually associated with other secondary pathogens such as honey fungus and can occur without any obvious dieback symptoms in the canopy. This makes identifying ‘dangerous’ Ash trees considerably harder. Basal lesions have been seen extensively across Europe and seem to be associated with areas of dense ash populations, and therefore spore load, where infection has been present for a long time. In particular, wet woodlands seem to be at highest risk from this form of infection in Europe, but further evidence is needed to assess the UK context. (Tree Council)
Recognising the visual symptoms of ash dieback is essential to assess the current health of the ash tree population – a necessary step to understanding the severity of the disease in an area.
The disease can affect ash trees of all shapes and size. While the symptoms are easily visible in young trees, they are often harder to recognise in more mature trees. Ash dieback can now be found in 49% of the UK’s 10km squares and over 68% of England’s 10km squares, and it may be even more widespread, as the symptoms can be difficult to detect, especially in large trees (Treecouncil)