Ash dieback (Hymenoscyphus fraxineus)

What is Ash dieback?

Ash dieback, caused by the non-native fungus Hymenoscyphus fraxineus (formerly known as Chalara fraxinea), presents a significant threat to the UK's treescape on a scale not seen since Dutch Elm disease in the 1970's.

Ash is the third most common native tree in the UK, occurring in woodlands and other landscape settings, it has a high ecological value, cultural and historical significance within the county. Ash dieback is now found throughout the UK, eradication of the disease is not possible as this pathogen is an airborne fungus and is now considered endemic within the UK.

How will Ash dieback be managed?

The Council (Surrey County Council) will focus on managing the risks posed from dying ash trees in high and medium risk locations and it will consider the nature conservation value that Ash provide.

The latest evidence suggests that at least 80% of the UK's ash will succumb to the disease, impacting both people and wildlife, presenting a significant risk management and economic challenge to The Council.

The Council recognises its duty to proactively manage the impact of ash dieback on their own landholdings, as well as promoting good management across the wider county.

The Council will retain Ash trees and monitor their disease progression where safe to do so, and in accordance with its tree risk management policy, only trees considered dead or significantly impaired or deemed a risk will be removed. Where possible timber will be chipped and processed, left at the site in the majority of cases.

The Council will carry out significant Ash dieback removal works outside of bird nesting season between September and March but will in necessary and specific circumstances need to remove dead or high-risk trees in accordance with its tree risk management policy, during this period after careful risk assessment and ecological considerations.

The Council will take action to reduce the landscape and biodiversity impact via the following methods:

  • Ecological surveys will be undertaken where necessary to determine presence of protected species (for example birds or bats) and where necessary replacement habitat or mitigation put in place.
  • Disease resistant trees will be identified, monitored and safeguarded where necessary.
  • Where appropriate deadwood will be retained in the form of wood piles or standing habitats as Ash trees die or are removed.
  • Allow for the natural regeneration of ash and for replacement tree cover, where appropriate, when the Council will also consider planting native broadleaf tree species, particularly as part of a management plan or under Forestry Commission directive. These trees will be locally, or UK grown and sourced to ensure proper biosecurity (disease prevention). To find out about our target to plant 1.2 million new trees by 2030, see Surrey's new tree strategy.

Finally, The Council will be clear in its communications to members of the public, elected Councillors and partnership organisations as to why it's carrying out Ash dieback related work on its managed land. The Council will constantly review the guidance around this disease to ensure work is in accordance with best practice guidance and up to date, based on information from a variety of sources.

Further reading