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The impact from Ash Dieback will be a highly significant, with big changes to our landscape

IntroductionWhat we are doingLandownersThe public



Hymenoscyphus fraxineus (previously Chalara fraxinea) is a fungal pathogen killing large numbers of ash trees across the UK.

The disease was first recorded in nursery stock in Britain 2012, before being found affecting trees in the wider environment in Norfolk and Suffolk in 2013.

The disease has now spread throughout much of the country and is well established in Somerset, found across the county, with many trees in areas such as the Mendips already dead or dying.

Somerset has a high density of ash trees, meaning the impact from Ash Dieback will be a highly significant, with big changes to our landscape.

What we are doing

Surveys have begun to identify dangerous trees on our road network, and tree removal has already started. Our departments are working with external organisations to develop an Ash Dieback Action Plan. This plan will seek to identify the issues raised by the disease and develop as thorough an understanding as possible of the likely outcomes.

Our core aims are to deal as effectively as possible with the risk posed from a large population of dying trees and to plan for the potential damage to our environment. To this end we have formed an Ash Dieback Resilience Group, bringing together representatives from a number of organisations.


Under the Occupiers Liability Act 1957 & 1984 landowners have a duty of care to make sure visitors or trespassers are safe on their property and that the public are safe from either falling branches or trees on their land or property.

Identifying the disease

Tree inspections – if you own or manage land where ash trees are near roads, public spaces or may be accessed by the public, it is vital that you monitor the health of these trees and take action by reduction or branch removal, or felling if and when it becomes necessary.

Contractors – ARB approved contractors directory

3:2:1 Replacement planting.
As landowners and managers you are custodians of our landscape and natural environment, the trees, hedgerows and woodlands on your land support much of the county’s wildlife and make Somerset a beautiful place for us all to live and work.

With the large numbers of ash trees likely to be lost it is vital to plan for the future, so we can mitigate the damage we are about to see.

If you’re removing trees use a formula of 321 for replacement.

  • Remove a large or mature tree – plant 3
  • Remove a medium or semi-mature tree – plant 2
  • Remove a sapling – use 1 tree

The public

Identification: Help on identifying the disease on the Forestry Research website,

Change to the landscape: With the potential up to 90% of Somerset’s ash trees likely to die. A large percentage of ash trees we see across our landscape in parks, gardens, woodlands, fields, hedgerows and road verges will disappear in the coming years. We will work with external bodies and seek to secure funding for replacement planting as far as is possible, and identify suitable, beneficial and sustainable locations to replant.

Last reviewed: October 25, 2023 by William

Next review due: April 25, 2024

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