National Trust statement on Ash Dieback Chalara fraxinea

Following the discovery of the deadly Ash Dieback Chalara fraxinea disease in the East of the country, the National Trust welcomes the fact that the Government has now introduced the ban on the importation of ash trees into the UK which came into force yesterday. 

The Trust is also pointing to the need to provide sufficient investment into tree disease research and more restrictions on plant movement.

It is also working closely with other key organisations and is prioritising the checking of ash trees thought to be currently the most at risk in the South East and East of the country.

Ian Wright, plant health specialist at the National Trust said: “We welcome the Government’s ban on the import of ash trees into the UK.  We are very concerned about what effect this disease will have on a key historic species – and on our landscapes. 

“As well as the threat to ash trees and woods across the country, we are particularly concerned about the risk to some of the magnificent old ash trees in our parkland and ancient woods. We have at least 300 of these on our register of veteran trees and many are over 300 years old. If this devastating disease took hold it would radically change some of our most special landscapes and places forever. These ash trees are also incredibly important for the rich flora and fauna only found on such ancient trees, which includes rare lichens, mosses and wood boring insects.

“A high level focus on tree disease is needed with more funding made available by Government for urgent work on how diseases spread and how to develop greater resilience in our woods.  We also believe there may be a need to put greater restrictions on International European trade in plants to reduce the risk of such disease spread.

“We are working closely with the Forestry Commission (FC), the Food & Environment Research Agency (Fera) and the Woodland Trust among many others to keep abreast of developments, and will take on board any guidance that is issued.

“We are currently checking the sites we believe to be at most risk in the South East and East of the country, prioritising where our most important ash trees are.

“We have already halted any planned ash tree planting on our land and are now weighing up the risk to ash trees of planting of other species that might be carrying the disease.  Our outdoor teams are already undertaking surveys of their ash trees while leaves are still on them to see if any are showing signs of the disease.  We will be referring any suspected cases to Fera and FC.

“We hope the Government will respond to the calls for an urgent summit to discuss ash dieback.”

Press wishing to interview Ian Wright should contact Jeannette Heard in the National Trust press office on 01793 817706 or 07884 473396 or email


1.  There is an estimated 80 million ash trees in the UK – a third of our entire tree population.  Ash is found throughout the country and grows in most soil types.  It regenerates profusely, and as climate changes, oak and beech woods are likely to become more dependant on ash in the future.

2.   In the early 1990s severe dieback of ash (Fraxinus excelsior) was noted in north-eastern Poland.  Trees of all ages were affected and typically displayed small necrotic patches on their stems and branches which later developed into girdling lesions resulting in wilting of leaves, tip dieback of branches and mortality of trees.   Initially, the cause(s) of the dieback were unclear but a species of Chalara was frequently isolated from lesions on symptomatic trees and by the mid-2000s this was recognised as both a new fungal species Chalara fraxinea and as the primary pathogen involved in the causation of ash dieback.

3.   Ash (Fraxinus excelsior) in Britain is the third most commonly recorded broadleaved species highlighted in the most recent Census of Woodlands and Trees, and is the second most widely planted broadleaved tree. Ash is found on a huge variety of site types, calcareous/acid, lowland/upland and throughout the UK.  Ash is an important tree in terms of its timber value and a key component of many habitats and feature of most landscapes.  It is also thought that ash will become a much more extensive and important element of many existing woods as it regenerates profusely and does not appear to suffer serious bark stripping by grey squirrels as do many other native broadleaved species. Because of these valuable characteristics, existing beech woodlands, PAWS restoration areas and even oak woods are likely to become more dependant on ash to survive as healthy and productive broadleaved woodlands.

4.   Since the early 2000s, Chalara fraxinea has spread rapidly across continental Europe with ash dieback now reported from the majority of European countries.  During 2012 interceptions of ash saplings infected with C. fraxinea, were found both in a number of key UK nurseries and shortly after out-planting. The outbreaks/original infection might have occurred as far back as 2009.

5.   Despite the detection of ash dieback in out-planted ash saplings, the pest is not yet considered to be established in the natural environment in the UK, since the infected plants are likely to have harboured the disease prior to planting and there is currently no evidence to indicate that transmission to other trees has occurred. However, the rapid establishment of the pest throughout many European countries, and the existence of appropriate growth conditions for the pest suggest that in the UK the potential for establishment is high and therefore the risk very high.

6.   The National Trust looks after 25,000 hectares (61,776 acres) of woodland and forest. We also conserve historic parks, gardens, commons and pasture-woodlands, where individual ancient ash trees are a highly prized resource – for their beauty and for the plants and animals growing on them – many of them direct descendants from the original Wildwood. The loss of these individual ash trees would mean the entire loss of these species from a site and even a region.


8 thoughts on “National Trust statement on Ash Dieback Chalara fraxinea

    • I’ve spoken to our plant health specialist, Ian Wright, and the 100,000 trees reportedly destroyed were young, recently outplanted nursery stock, so not mature trees. These would be disposed of in a way that prevents the disease from spreading. The two key ways of doing this is either through burning, or by burying them deep underground.

      • Thanks for the reply when they are burnt is it on the spot where they are cut or do they need covering when burning to prevent the spread of the desease.
        I guess that it has to be where they fall. Good to know it’s just the young trees.

        Why did we import from abroad I thought Ash was happy to self seed!

      • Yes ash are prolific seed baring trees. However we import over 50% of all broad leaved trees for forest planting. In this case the seed was collected in the UK sent to another EU country for germination and growing on (possibly exposed to infection) then eventually ending back in our UK nurseries for selling to customers.

  1. Pingback: Ash Dieback (Chalara) | Woodland Matters

  2. What I want to know is why Joan Webber (ICF?) is ignoring the Swedish research which alludes to or is suggesting a policy that allows resistant trees to survive and recover the population with resistant genes. This is logical and in keeping with such parthenogenesis in populations. however the statement I read earlier by Joan said in the telegraph-

    quote here “Joan Webber, the Forestry Commission’s principal pathologist, says she and her team have studied European research but supports the policy of burning trees because the risk of destroying resistant ash is outweighed by the need to contain the disease”.
    Prof Stenlid disagrees. “The only smart way to face the future,” he says, “is knowing it is impossible to eradicate the fungus.” He says it is likely to be here for decades, but, if we take heed of his research, so could the native ash.

    so what i want to know is why are we ignoring the sensible approach? It is crazy and in no way makes any reasonable or biological sense, micro biology loose in the wild cant be contained its airborn and microscopic!

  3. Pingback: National Tree Week 2012 « LEARN FROM NATURE

  4. Pingback: Ash Dieback and the threat to our cultural trees | National Trust Press Office

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