Ash dieback continues to present a significant challenge for landowners, local authorities and organisations responsible for trees across the UK.

The issue has been brought into focus again this week following news that The Parks Trust in Milton Keynes is preparing to remove ash trees affected by the disease across several of the city’s woodlands. With ash making up a significant proportion of the local tree population, the Trust has described the situation as a serious challenge, with work being undertaken before the disease progresses further and affected trees become an increased risk to the public.

It is a situation being faced by organisations and land managers across the country.

What is ash dieback?

Ash dieback is a fungal disease caused by Hymenoscyphus fraxineus. First officially identified in England in 2012, it is now widespread across the UK and affects our native common ash (Fraxinus excelsior).

The disease can cause leaf loss, crown dieback and lesions on branches and around the base of the tree. As the condition progresses, affected trees can become increasingly weakened and may be more vulnerable to secondary infections.

Not every infected ash tree will die. Some show greater tolerance than others, making correct identification, monitoring and informed management particularly important.

Why does ash dieback create a safety issue?

For organisations responsible for trees alongside roads, railways, public rights of way, parks, workplaces and other frequently used areas, ash dieback is more than a tree-health issue.

As affected trees deteriorate, branches can become brittle and the structural integrity of the tree may be compromised. This can increase the risk of branch failure or tree collapse and can also make work on severely affected trees considerably more hazardous.

The Forestry Commission advises landowners and managers to consider the risks posed by infected ash in safety-critical locations and to assess and manage those risks appropriately.

Early recognition and ongoing assessment can therefore play an important role in determining what action is required.

Recognising the signs

People responsible for inspecting or managing trees should be alert to common signs associated with ash dieback, including:

• thinning or dying areas within the crown
• dead shoots and branches
• premature leaf loss
• dark lesions on branches, stems or around the base of the tree
• new shoots developing from the trunk or main branches
• an increasingly sparse canopy

However, poor crown condition does not automatically mean that a tree has ash dieback. Drought, root damage, waterlogging and other pests and diseases can produce similar signs.

Understanding what to look for – and recognising when further specialist assessment is needed – is therefore essential.

From identification to safe management

Managing ash dieback is not simply a case of identifying an affected tree and removing it.

The condition of the tree, its location, the level of public access, surrounding infrastructure and the progression of the disease all need to be considered.

Where intervention is required, the condition of diseased ash can also significantly affect how work should be planned and undertaken. Current Forestry Commission guidance highlights the potential for the structural strength of affected trees to be severely compromised and recommends that work on trees displaying obvious or advanced symptoms is undertaken only by appropriately trained and experienced professionals.

For employers and organisations, this makes knowledge and competence an important part of an effective ash dieback management strategy.

Ash Dieback training from KNW Training

KNW Training provides specialist Ash Dieback training for organisations and individuals involved in the inspection, management and maintenance of trees.

Training can help learners develop a greater understanding of the disease, recognise key symptoms and appreciate the risks associated with affected trees and their management.

Courses are particularly relevant to those working within:

• forestry and arboriculture
• local authorities
• highways and infrastructure
• utilities
• estates and facilities management
• parks and public spaces
• land and countryside management

With ash dieback continuing to affect trees throughout the UK, ensuring those responsible for tree safety have the appropriate knowledge and awareness is increasingly important.

Need Ash Dieback training for your team?

KNW Training delivers accredited and specialist land-based training nationwide. Contact our team to discuss your requirements and the most appropriate training for your organisation. Call us on 01677 424633 or email info@knw.co.uk