Fifty trees in Bangor will have to be felled after it was discovered they have ash dieback disease.


The discovery was made recently while land near the Ffriddoedd area of Bangor, known locally as ‘Donkey Lane‘ (adjacent to Trem Elidir), was being cleared and tided up by contractors. The trees will now have to be cut down in an attempt to limit the spread of the disease.

It’s estimated that Ash dieback – Scientific name Hymenoscyphus fraxineus – will kill up to 95% of ash trees across the UK, at a cost of billions, and will change the UK landscape forever as well as threatening many species which rely on ash trees.

The disease can affect ash trees of all ages. Younger trees succumb to the disease quicker but in general, all affected trees will have these symptoms:

What happens to the tree?

The fungus ‘over winters’ in leaf litter on the ground, particularly on ash leaf stalks. It produces small white fruiting bodies between July and October which release spores into the surrounding atmosphere.

These spores can blow tens of miles away. They land on leaves, stick to and then penetrate into the leaf and beyond. The fungus then grows inside the tree, eventually blocking its water transport systems, causing it to die.

The tree can fight back, but year-on-year infections will eventually kill it.

How did ash dieback get here?

Ash dieback is a fungus which originated in Asia. It doesn’t cause much damage on its native hosts of the Manchurian ash (Fraxinus mandshurica) and the Chinese ash (Fraxinus chinensis) in its native range. However, its introduction to Europe about 30 years ago has devastated the European ash (Fraxinus excelsior) because our native ash species did not evolve with the fungus and this means it has no natural defence against it.

The spores of this fungus can travel in the wind so it is possible that it arrived in the UK naturally however it was also inadvertently imported on ash saplings. The UK was importing thousands of ash plants from infected parts of Europe until a ban came into place in 2012. This undoubtedly sped up the spread of the disease within the UK because the disease was able to spread from areas of new planting via wind to mature trees.

What impact will ash dieback have?

It’s thought that we are going to lose up to 95% of our ash trees in the UK. This is going to have a devastating impact on the landscape and the biodiversity of our woodlands, as well as a major loss in connections between habitats as we lose hedges and individual trees outside of woods.

The predicted cost of managing the diseases is high, up to £15 billion. It includes the practical expense of clearing up dead and dying trees, to the loss of its environmental services such as air purification.

Is there any hope?

There is hope on the horizon. Initial findings suggest that we might have some trees that are tolerant to ash dieback, meaning that the population could eventually recover over time, but it’s likely to take over 50 years.