13 Mar Ash Dieback Disease
Ash Dieback Disease
Ash-dieback disease (often called chalara) is a serious and rapidly spreading disease of ash trees that has had a significant impact on forests and landscapes in Ireland and many other countries in Europe. The disease is caused by a fungus called Hymenoscyphus fraxineus, which infects ash trees and causes a dieback of the shoots and branches. The fungus spreads through spores that are carried by wind and insects, and it can also be transmitted through the movement of infected plant material, such as ash seedlings or saplings.
Ash-dieback disease was first identified in Ireland in 2012, and since then it has spread rapidly across the country. The disease has the potential to affect all ash trees in Ireland, and it has already caused significant mortality in many areas. Ash is a common and ecologically important tree species in Ireland, and it is found in a wide range of habitats, including forests, woodlands, hedgerows, and urban areas.
Symptoms of Ash Dieback Disease
The wide range of symptoms associated with Hymenoscyphus fraxineus includes:
- Necrotic lesions and cankers along the bark of branches or main stem
- Foliage wilt
- Foliage discolouration (brown / black discolouration at the base and midrib of leaves)
- Dieback of shoots, twigs or main stem resulting in crown dieback
- Epicormic branching or excessive side shoots along the main stem
- Brown / orange discolouration of bark
(Note: The symptoms described above are not exclusive to Hymenoscyphus fraxineus and may be attributable to a number of other causal agents or factors, e.g. frost.)
The impact of ash-dieback disease on Irish forests and landscapes has been significant. The loss of ash trees has led to changes in the structure and composition of affected forests, with a reduction in the diversity of tree species and a potential increase in the dominance of other species. This can have consequences for the ecosystem services provided by these forests, such as timber production, carbon sequestration, and habitat for wildlife.
In addition to the ecological impacts, ash-dieback disease has also had economic and social consequences for Ireland. Ash is an important timber species in Ireland, and the loss of ash trees has reduced the availability of ash wood for commercial use. The disease has also had an impact on the amenity value of forests and landscapes, as the loss of ash trees can lead to a reduction in the visual appeal of these areas.
To address the spread of ash-dieback disease in Ireland, a number of measures have been put in place by the government and other organizations. These measures include ash-dieback grants under the ash dieback scheme (or RUS Scheme – Reconstitution and Underplanting Scheme), the implementation of a ban on the import, sale, and planting of ash trees and other plant material, as well as the development of guidelines for the management of infected trees and forests. In addition, research is ongoing to develop methods for the control and containment of the disease, including the use of resistant or tolerant ash tree varieties and the development of biological control methods.
Ash Dieback Grants
These grants are available to any landowner impacted by the disease. Funding is there for a range of measures, depending on the conditions of the site, and covers clearance, partial clearance, reconstitution, and underplanting. Unfortunately (and in my opinion very wrongly) there are no associated premiums or payments as compensation at present.
Despite these efforts, ash-dieback disease is likely to continue to have a significant impact on Irish forests and landscapes in the coming years. The long-term management of infected forests and landscapes will require a combination of measures, including the removal and replacement of infected trees, the development of diverse and resilient forest ecosystems, and the use of management practices that support the health and vitality of affected forests.
Ecoplan Forestry specialise in the management and control of ash dieback, and the associated ash dieback grants, while implementing the principles of Ecoforestry. For more information Contact Ecoplan Forestry
You can learn more about Ash Dieback Disease research from the UK Forestry Commission Here