Saturday, 22 October 2016

Help us spot early signs of Chalaria Ash dieback

To all walkers, runners, cyclist, dog walkers, sun bathers
 and anyone who loves trees and woods

Help us spot Chalaria dieback on Ash trees


Ash tree leaf


The county botanist, Julian Woodman, confirmed what we have been suspecting for some time: Chalaria dieback of ash has spread to the west of the Vale of Glamorgan and westerly winds are likely to carry the spores of Chalaria towards Barry and Porthkerry Park.




What causes Ash Dieback
Ash dieback is caused by the fungal infection of, H. fraxineus, which is mainly spread by wind.. The fungal spores settle on the ash tree leaves and can cause symptoms within about 2 months. The main time for the infection to spread is June to October, the first symptoms such as blackening of the leaves, can be seen in the spring following the infection.

Signs of dieback on the Ash tree:
                                                         
Chalaria fungal growth on twig
(google images)
                              Winter: diamond shaped lesions on the branches                                                           
  Spring/Summer: blackening of twigs and leaves, dieback of crown of tree
Autumn: small fungal bodies on twigs and leaves fallen off the tree




Diamond-shaped lesion on Ash tree
(google images)
Healthy and diseased leaf of Ash tree
 (photo: Imperial College London)

black bud of Ash tree
How to recognise and Ash tree?
See the leaf shape in the above pictures: pinnate leaf with oval shaped leaflets. In winter the distinctive large black buds can be seen at the tips of the twigs. Ash are very prolific seed – producers and there are usually plenty of seedlings near established Ash trees.

What will happen to an infected Ash tree?
Once an Ash tree is infected, it cannot recover from the infection. Young trees (under 10 years old) are likely to die within ten years of being infected. Ash trees between 10 to 40 years old are likely to die, if they are also infected by honey fungus. Older trees, over 40 years old, are likely to survive with the disease present, and are still able to support a wide variety of wildlife.

If Chalaria dieback of Ash is suspected, the rangers, park staff or local wildlife group will take records and report it to Natural Wales (E: treehealth@cyfoethnaturiolcymru.gov.uk ). There decisions will be taken, if trees need to be removed to prevent further spread.

References:
Observatree (monitoring tree health) – Poster of Ash tree affected by chalaria

Forestry Commission

Notify suspected Chalaria info: http://www.forestry.gov.uk/chalara#Reporting suspected cases

DEFRA