Ash dieback in Gloucestershire

The future of Gloucestershire’s woodlands is threatened by ash dieback, a fungal disease affecting ash trees with a fatality rate of 70-85% over a 20-year period.

Ash dieback, Hymenoscyphus fraxineus, is a fungus which originated in Asia, where it lives on the decaying leaves of other members of the ash family. While it doesn’t cause much damage

to the ash trees in its native range, its introduction to Europe about 30 years ago has been devastating European ash species. They didn’t evolve with the fungus, and therefore have no natural defence against it.

Ash is estimated to account for more than 10% of the canopy in 90% of woodlands in the county and, in some cases, it forms 80-100% of the canopy. It's a common and important tree in woodlands, open habitats and hedgerows, and is a frequent early coloniser of open land – meaning that you’ll see ash saplings appearing long before any other kind of tree. Ash allows a significant amount of light to reach the woodland floor – resulting in a wide variety of woodland wildflowers and plants. Ash dieback has huge implications for wildlife, with over 1,000 species relying on ash trees as their core habitat.

A number of species associated with deadwood habitats may thrive for a short period in the conditions created by ash dieback, but 50% of species that rely on ash now at risk of extinction within 50 to 100 years.

There is a continued effort to monitor and identify trees that seem to show resistance to the disease, and we are encouraging natural regeneration from these individuals. There is a continued effort to monitor and identify trees that seem to show resistance to the disease, and we are encouraging natural regeneration from these individuals.

Please take care when visiting wild spaces that have ash trees; there is a risk infected ash tree limbs may become brittle and break, possibly falling on to paths and roads. Gloucestershire Wildlife Trust are working hard to make sure that the nature reserves we manage are as safe as possible, this will involve essential tree safety work at many different reserves.