Preventing the spread of tree disease
It is important that you take care when visiting forests, and act appropriately to prevent the spread of tree disease.
Ash Dieback disease
Ash Dieback is a serious disease of ash trees caused by a fungus called Chalara fraxinea. The disease causes leaf loss and crown dieback in affected trees and can lead to the death of the tree.
Ash Dieback has been identified in young ash saplings at a number of sites in Northern Ireland. You can get up-to-date information on the Department for Agriculture and Rural Development (DARD) website at the following link:
Phytophthora lateralis (P. lateralis)
Phytophthora lateralis infects tree roots which come into contact with spores in the soil or water, and it kills most Lawson cypress trees it infects.
Public forests affected
P. lateralis is present in a number of locations, including:
- Tollymore Forest
- Mourne Forest
- Somerset Forest
A very small number of affected trees have also been identified in Castlewellan and Belvoir Forests.
The implementation of measures to control the spread of P. lateralis is ongoing. Public access to certain areas of these forests is restricted to prevent soil movement, and users of the forests are asked to observe signage and remain on the way marked paths.
How can I identify Lawson cypress trees and P. lateralis?
Anyone concerned about Lawson cypress trees are asked to access the guide below where information on the identification of Lawson cypress and P. lateralis symptoms is available.
- Guide to identification of Lawson cypress and Symptoms of Phytophthora lateralis (723 KB)
- Help with PDF files
If land owners are concerned about the disease they should then email with their name, address and contact details, and a photograph of the tree to the email address below.
Phytophthora ramorum (P. ramorum)
P. ramorum has the potential to cause serious damage to woodlands and plants in the wider environment.
How can you identify Japanese larch trees and P. ramorum?
The first indication of the disease on Japanese larch trees is a visible wilting of young shoots and foliage. Later in the growing season, signs of the disease include withered shoot tips with yellowing needles, which then become blackened. The infected shoots shed their needles prematurely. Trees may also have bleeding cankers on their upper trunks.
All woodland owners and managers are asked to look out for symptoms of the disease in Japanese larch and report suspicious symptoms to Forest Service by:
- phone: 028 9052 4480
Further information on the disease is available from the Forestry Commission website:
Public forests affected
Since the first outbreak in 2010, the following public forests have been affected:
- The Fews
- Tievenadarragh (part of Bohill Forest)
- Moneyscalp (part of Tollymore Forest)
Tree disease can be spread in many ways, including:
- on footwear
- on vehicle wheels
- on tools and machinery
- by the movement of infected plants
- in rain, mists and air currents
If you’re visiting a forest, please pay attention to signs showing what you can do to help prevent spread of the disease. These include:
- avoiding any action which could result in the movement of infected soil or plant parts to uninfected areas
- keeping to forest roads
- keeping dogs on leads
- removing soil and mud from shoes and boots before leaving the woodland