Planning a visit?

Living & Working


Visit the Dales


Chalara ash dieback (Chalara fraxinea)

The landscape of the Yorkshire Dales National Park is characterised by important ancient semi-natural ash woodlands. These woodlands also contain rare and endangered plants and insects. At the moment ash trees are threatened by a disease called Chalara ash dieback which has recently been found in the wild in East Anglia and in recently planted new native woodlands.

Chalara ash dieback is a serious disease of ash trees which is caused by a fungus called Chalara fraxinea (C. fraxinea). The disease causes leaf loss and crown dieback in affected trees, and it can lead to tree death. Ash woodlands contain a number of tree species including ash, rowan, hazel, hawthorn and holly. We consider ash woods are a priority habitat. We will monitor the progress of the disease and will try to ensure that these habitats continue to be safeguarded.

National Park Authority involvement

YDNPA staff are working closely with colleagues at the Forestry Commission. A Trees and Woodlands Officer has been seconded, part time, to the Forestry Commission and has recently completed surveys of ash woodlands within the National Park in order to help to establish whether C. fraxinea exists here. As of 13 November 2012, no cases have been confirmed. The National Park Authority is now waiting for the Government to publish the action plan for tackling the outbreak following the National Survey and the recent national summit on C.fraxinea

The monitoring and maintenance that is carried out by Dales Volunteers has been stopped pending information about the distribution of C. fraxinea within the National Park.

More information

The most up-to-date information and the Government's response to the crisis is available from the Department for the Environment, Food & Rural Affairs website at

The Forestry Commission's website,, provides first hand information and a more practical interpretation about the disease, how to recognise it, the current distribution and what the current status is can be found on the Forestry Commission website at

Details of the situation locally were issued in a press release by YDNPA on 2 November 2012.

Help for farmers

From grants to stewardships, we can help

Wildlife Conservation

We can advise on all aspects of wildlife conservation