The Issue Explained: What is Ash Dieback?

Siobhan Brocklehurst

Ash dieback, caused by the fungus Hymenoscyphus fraxineus, is a devastating disease affecting ash trees across Europe, including the UK. Since its first identification in Poland in the early 1990s, it has rapidly spread, leading to significant ecological and economic impacts. The fungus originates from Asia, where native ash species exhibit resistance. However, European ash species lack this natural defence, making them highly susceptible. The disease spreads through airborne spores released by the fungus’s fruiting bodies, which infect ash trees by landing on their leaves. Over time, the fungus grows into the branches and trunk, disrupting the tree’s vascular system and leading to dieback and often death.

In areas like Coleorton, ash dieback poses a significant threat to local woodlands. The loss of ash trees affects biodiversity, as numerous species rely on ash for habitat and food. Additionally, dead or weakened trees present safety hazards, particularly near pathways and public spaces.​

Recognizing the symptoms of ash dieback is crucial for early intervention. Some key indicators include:

Management and Conservation Efforts

At Coleorton, conservation volunteers have been proactive in addressing ash dieback, by undertaking a number of strategies advised by the Woodland Trust and The Tree Council including:

• MONITORING regularly to identify and assess ash tree health;
• SELECTIVE FELLING of infected trees to mitigate hazards and reduce disease transmission;
• PROMOTING BIODIVERSITY by encouraging the growth of a diverse range of native tree species to enhance ecosystem resilience.

Looking Ahead

While ash dieback presents significant challenges, concerted efforts by local communities, conservation groups and authorities can mitigate its impact.  Ongoing research aims to identify resistant ash strains and develop effective management strategies.  Public support and engagement remain vital in preserving our woodlands for future generations.

What can you do to help?

If you identify a new case of ash dieback in the UK, you can report it online via Tree Alert; contact the Forestry Commission via info@ashdieback.co.uk or call them on 01626 773499.