In 2012, a fungal pathogen was formally identified in the British countryside (Hymenoscyphus fraxineus or commonly known as Ash Dieback Disease). Thought to have been introduced through the importing of Ash tree saplings from the Netherlands. Having first been discovered in Poland in 1992, the disease has slowly worked its way across Europe, killing millions of Ash trees along the way. Some recent findings suggest the disease may have been introduced into the UK at a much earlier date (2005), spreading via airborne spores to neighboring Ash trees.
How to tell if your tree might be infected
There are many visual signs which can be used to identify the presence of Hymenoscyphus fraxineus:
- Top branches have no leaves on during summer
- Crown dieback/ weak looking crown
- Dark diamond shaped lesions on the bark in younger trees
- Young growth sprouting from the stem or main branches
- Tree has a ‘Pom Pom’ look
Very heavily effected trees typically become very brittle with branches often snapping out. This has the potential to cause serious problems if those trees are located near roads or Public rights of way. It has been estimated the cost of dealing with all the Ash trees along the UK roadways is going to cost well over 15 billion pounds.
What should be done?
Some resilience has been recorded but it is estimated that 85-90% of Ash trees in the UK will die.
Ash trees abounding to roads or public rights of way should be surveyed and monitored as a minimum. If the dieback exceeds 50% of the crown the tree should be removed. However felling should be pre-empted and planned at 30% crown dieback.
Ash trees within the wooded landscape can be removed through selective thinning or felling but good practice dictates a small number of Ash trees should be left (providing they are in a non-hazardous area) in order to offer some resilience.
It’s worth noting that even though the trees are diseased they may require a felling license. This can be obtained from the Forestry Commission
How can the government help me?
If you are removing areas of infected ash through a clearfell or selective fell regime in a woodland, you may be eligible for a Tree Restoration Grant. This is a capital grant that lasts for a period of 2 years and will contribute towards the costs of replanting. A typical grant will pay £2.88 for a tree to be planted in a shelter guard. Wessex Woodland Management may be able to both help you apply for a woodland grant and create the new woodland.
What does the future hold for Ash trees?
There are some uses for the felled timber, such as making Ash charcoal. Although the immediate future for Ash in the UK is quite bleak, however some resistance has been recorded. As a result some breeding programs are underway. In the meantime best practice is to restock with a robust mix of site suitable species to ensure our woodlands are resistant to the impacts of climate change and future pests and diseases.