Around 800,000 trees in Exmoor National Park may be at risk from ash dieback, the National Park Authority has warned, as work to clear potentially hazardous infected trees from land it owns gets underway in Simonsbath this week.
The estimate comes from a Forestry Commission report produced on behalf of Exmoor National Park last summer*. It follows a University of Oxford study last month predicting a nationwide cost of £15 billion to the British economy linked to ash dieback**.
Ash is the second most common native tree species in Exmoor National Park after oak. It’s estimated that at least 95 per cent of ash trees in the UK will be killed by ash dieback over the next 20-30 years.
Graeme McVittie, Exmoor National Park Authority Senior Woodland Officer, said: “The trees being felled in Simonsbath next week are on Exmoor National Park Authority land and will be the first of many that will be sadly missing from the Exmoor landscape in years to come. We always conduct a thorough check for nesting birds and if possible delay any tree work to avoid disturbing them. But because this disease progresses so rapidly we have to act quickly before trees become too hazardous.
“Many of the diseased trees won’t need removing and may even provide temporary benefits to wildlife – for example populations of woodpeckers and stag beetles peaked following Dutch elm disease in the 1980s. Yet the longer-term loss in terms of public benefits such as clean air and water and carbon storage is likely to be significant.
“We are committed to the government’s national action plan on ash dieback, which focuses on building resilience and encouraging tolerant species of ash and are happy to provide expert advice to anyone with concerns. It is always the landowners’ responsibility to deal with any diseased trees that may present a risk to the public.”
Ash dieback disease is caused by the fungus Hymenoscyphus fraxineus. It causes leaf loss and crown dieback and once infected a tree will usually die, often as a result of the infection weakening the tree so it becomes more susceptible to attack by other pests and diseases.
There is no requirement to notify Exmoor National Park Authority about ash dieback but the Forestry Commission is collecting data about this and other tree diseases at www.forestry.gov.uk/treealert.
Exmoor National Park Authority has recently set up a new CareMoor Tree Fund for people wishing to donate towards replacing any cherished tree that has been lost from the landscape for any reason. Find out more at www.exmoor-nationalpark.gov.uk/caremoor.
* National Forest Inventory statistics for Exmoor National Park, Forest Research, July 2018, Online at: file://srvfs-app1/userdirs/astevens/VM_redirect/downloads/FR_NFI_Exmoor_Report_2018.pdf
** The £15 billion cost of ash dieback in Britain, Current Biology, Louise Hill et al, May 2019, DOI: https://doi.org/10.1016/j.cub.2019.03.033