Ash dieback, also known as Chalara, is a very contagious fungal disease. It poses a severe threat to our native ash trees and non-native members of the ash family. Ash trees are valuable features of Torbay’s landscape. They are in our native woodlands and hedgerows.
Ash dieback affects ash trees (Fraxinus excelsior). The cause is the fungus Hymenoscyphus fraxineus. This also goes by the names Chalara fraxinea and Hymenoschyphus pseudoalbidus. It blocks the water transport systems in trees and causes:
The disease came over from mainland Europe. It was first noted in Poland in 1992. It has infected and affected most of the Ash on the continent. It was first found in the UK in 2012 at sites that had received saplings from nurseries.
Since then, the spread of the disease has now reached most areas of the UK. In Torbay at the start of the 2019 summer there were signs of a high percentage of infected trees. Some trees do appear more infected than others. There may be some resilience to the disease within some of the specimens.
Usually once the tree has reached around 40% mortality it’s unlikely it will respond. It will probably die due to the disease, or because of its weakened state. The rate of decline once infected can vary. Some trees die quickly, and others hang on a bit longer.
There is no known cure for the disease. Some trees have a genetic resistance and remain unaffected or can tolerate the disease. These trees may help us to understand the mechanics of the resistance. They may enable the re-stocking of the Ash.
Further information
These videos give guidance for managing ash dieback and show samples affected.
We will have to act if infected trees pose a significant risk to people, property or traffic. This will result in the loss of some of our landmark trees and the general removal of the Ash population.
To identify the areas where we might need to intervene, we will assess areas that are high risk. We will also look at Ash trees that are next to, or opposite, those that pose a risk.
When work on the trees is being carried out, we will display boards to show that the work relates to Ash dieback.
Some larger Ash trees are on private/residential land. Household owners, or those responsible for the trees, will have to manage these. Normal processes still apply if the tree is:
A qualified person should identify the disease and make the necessary recommendations. This is because in some instances an Ash may show signs of decline, but the cause may not be Chalara ash dieback.
There will be many opportunities for replanting. We are currently looking into the most suitable species to replace the Ash with. The species used is likely to be diverse. This will increase resilience within the tree stock and promote greater biodiversity.
These will take a long time to reach the mature heights of some of the removed Ash. They will however provide significant succession planting. These new trees will provide future amenity and biodiversity within Torbay. They will provide a green environmental legacy for future generations to enjoy.
As part of the ongoing action to mitigate the loss of Ash trees, a range of initiatives will take place. We will encourage:
This engagement is vital to establish the future tree cover within Torbay. We may use both native and exotic species. One of the outstanding features of Torbay is the benefits of being able to plant exotic species. They not only survive but thrive in our environment. This diverse range of planting will help Torbay recover from the loss of the Ash tree. It will provide resilience as we move forward.