The UK’s third most common tree is now under threat by Hymenoscyphus fraxineus otherwise known as Chalara Ash dieback.It is a fungus, which causes the leaves and the crown to die back. Ash dieback is now a common feature in the UK and will drastically effect the landscape as it spreads across the UK over the next few years. Not much is known about how to protect the trees, other than preventing transport of affected trees and preventing the sale of saplings. The fungus seems to be spread by the wind,so people are asked to be aware of biosecurity and to prevent spreading the disease by taking fungus from one woodland to another on their boots.
The Ash trees in Sanctuary Woods were reported as having chalara ash disease in 2018, which will start to kill off the younger saplings first and the older trees in the next decade. Observations are being made on which trees are effected, how the disease has impacted and if any remain unaffected or show signs of recovery. Ash dieback started in Russia and Poland with only a low percentage remaining unaffected and observations indicate that some mature Ash trees seem to be resistant to the disease. An Ash tree needs to die back and then recover in order to find a solution to grow resilient young trees.
The Woodland Trust charity are currently working with Kew Science to collect seeds from from native Ash (and Alder) to safeguard genetic diversity and they are giving some seeds to the universities to carry out further research. Many organisations such as the Forestry Commission, Observatree, National Trust, Woodland Trust, and Fera are working to create UK Tree Healthy Early Warning System to identify and monitor health and disease of our trees. DEFRA and a number of organisations are working hard to fund research to combat tree disease.
Fighting Tree Disease – The Woodland Trust
Banking the UK seeds – Kew Science