A fatal fungal disease of ash trees
First confirmed in the UK in 2012, ash dieback, also known as 'Chalara' or Chalara ash dieback, is a disease of ash trees caused by a fungus called Hymenoscyphus fraxineus.
Ash dieback has already caused the widespread loss of ash trees in continental Europe and is now affecting countless woodlands, parks and gardens across the U.K, including our nature reserves.
The Trust manages 1,500 hectares of woodlands in Surrey. Surveys across these woodlands have identified that extensive areas of ash trees are infected by the disease. The Trust has removed over 80 dangerous or fallen ash trees from areas including footpaths and bridleways from 1 April 2017 to 31 March 2018 and is concerned that these numbers will increase.
As the estate is very popular with local people and receives around 1.3 million visitors per year, public safety is a key concern. The Trust has carried out a review of the woodlands in line with updated guidance from the Forestry Commission and considered the National Tree Safety Group’s Ash dieback guidance.
As such the Trust has determined that the selective felling of ash trees which stand within thirty metres of public and permissive footpaths, bridleways, roads, boundaries of neighbouring properties and other high risk features is the most appropriate action.
Find out more about ash dieback symptoms and our safety works below
Ash dieback symptoms
The main symptoms of ash dieback are:
- Blackening of leaves which often hang on the tree
- Discoloured stems, often with a diamond-shape lesion
- Black and shrivelled shoots
- The death of twigs and branches in the crown of mature trees
- Small white fruiting fungal bodies on blackened stalks in early autumn
The disease causes ash trees to die
Young ash trees die quickly, whilst mature trees can be killed by a yearly cycle of repeated infection. Diseased trees may also get honey fungus, causing branches or whole trees to collapse.
Ash dieback FAQ
What is Ash dieback disease?
First discovered in the UK in 2012, Ash dieback is a fungal disease affecting Ash trees. The disease is now present in all counties of England. Experience in Europe suggests that the majority of Ash trees in woodlands infected with the disease will decline and die.
How widespread is Ash dieback disease in Surrey?
Surrey Wildlife Trust manages 1,500 hectares of woodlands in Surrey. Surveys across these woodlands have identified extensive areas of Ash trees are infected by the disease.
Why are you taking action now?
The Trust has carried out a review of the woodlands in line with Ash dieback guidance from the Forestry Commission, which was updated on 20th September 2018. The Trust has also considered the National Tree Safety Group’s Ash dieback guidance.
The presence of both Ash dieback and honey fungus increases the risk of Ash trees dying and becoming unstable.The Trust has already removed over 80 dangerous or fallen Ash trees from areas including footpaths and bridleways from 1 April 2017 to 31 March 2018.
Public safety is a key concern as the estate is very popular with local people and receives around 1.3 million visitors per year.
Taking no action is not an option as the risk to public safety is considered unacceptable.
What action are we taking?
In order to protect public safety, the Trust will carry out the selective felling of Ash trees which stand within thirty metres of public and permissive footpaths, bridleways, roads, car parks and boundaries of neighbouring properties over the next few years.
Ash trees in the middle of woodland will be left for nature to take its course.
Which reserves will be affected?
All Surrey Wildlife Trust sites with Ash trees are likely to be affected by the disease. But we are taking a phased approach to dealing with the problem, starting in November 2018 with the following sites:
- Norbury Park
- Shere Woodlands
- Staffhurst Wood
Detailed maps are available from the FC – please contact email@example.com
Who is doing the work?
Surrey Wildlife Trust has instructed specialist contractors to carry out the work, who are experienced at working on sensitive sites. The work will be carried out using a forest harvester which fells the tree and takes the branches off mechanically. Due to the extent of the disease it is too dangerous to use chainsaw operators for this work.
How will the works impact wildlife?
We will prioritise felling during winter, outside of the bird nesting season, to minimise the impact on the environment and wildlife.
As part of the works, we are liaising with interested parties including bat, badger, butterfly, dormouse and botanical groups.
We will continue to carry out ecological surveys on all the areas identified for selective felling to ensure the appropriate methodology and mitigation measures are followed.
Opening rides and glades will bring more light to the forest floor, so we may see more butterflies, orchids and other species benefitting longer term.
How will we replace the trees?
The woodlands will be left to regenerate naturally with a range of tree species including, hopefully, some disease tolerant Ash trees.
Those ash saplings that are not resistant to the disease will die within a few years and will not pose a safety risk due to their limited size.
If this does not happen, the area will be considered for restocking with an alternative native species. Progress will be reviewed on an ongoing basis.