Will the Common Ash (Fraxinus excelsior) continue to be used for the future production of solid wod panels?
The extinction of the ash tree in Europe has been discussed in numerous academic articles and debates. Field professionals are well aware that a disease that seriously endageres the ash called Charala fraxinea is caused by fungus Hymenoscyphus fraxineus. Moreover, recent scientific evidence confirms that an invasive beetle, Emerald Ash borer (Agrilus planipennis), also contributes greatly to the extinction of ash tree.
Nevertheless, the interest in ash solid wood panels has grown steadily in the recent years. For example, during 2016 we delivered to our clients twice the quantities of the ash solid wood panels compared to previous years. These deliveries are particularly to the Scandinavian countries for the production of staircases and kitchen worktops.That is why I have also decided to reflect upon this pressing issue from the perspective of the future of ash as a traditional material for the wood production.
On the 23rd November 2016, together with our partners from 2MAX company (which is also processing ash logs in their production), we visited flood-plain forest in Hornomoravský úval near city Kojetín in Czech Republic. Curious to verify the status quo personally, we visited a mixed oak-ash stand forest together with Mr. Benčik who hold a function of professional forest manager in this area. In this particular forest stand that visited, ash trees represented 38% of the forest.
Mr. Benčík, expert in the filed of forestry, provided us with a large amount of valuable information, which unfortunately ,are together with the available research, as well as our practical experience, only confirming the significance and urgency of this issue.
The expert consulted firstly observed the problem with Chalara fraxinea in young forest arround 1998. However, at this time he was not aware that what he observed is a fungal disease, which most likely came to Europe from Asia.
So what exatly happens to an affected ash tree? At the onset of the disease the crown is getting thinner and consequently, the thinner branches die away (see Picture 1). At this stage of damage it is still possible to minitage, and ensure that such ash trees are used economically, e.g. it is still possible to use ash logs for panel production.
The later stage symptoms represent necrosis accompanied by staining wood (see Pictures 2,3,4), ligniperdous insect attack (see Picture 5), die away of root system, gradually drying and shedding of the bark (see Picture 6). This stage of the disease is clearly visible also by layman.
An ash tree at this stage of disease will dry out and most probably, by the effect of wind, will fall down (see Pictures 7,8). Indeed, such timber is neither usable for panel production any more, nor for any further wood processing. It can be used only as firewood.
Even more allarming is that the disease Chalara fraxinea attacks the ash trees of all age categories. Mainly young forest stands are vulnerable, but one year old plants could be attacked as well. In the forest stand that we visited the oldest ash trees are around 120 years old. These older trees survive better as they are better equipped to recover (see Pictures 9,10).
Yet, the forest stand we visited, because of Chalata fraxinea is harvested by the clear cut method (see Picture 11). This means that paradoxically also the resistant ash trees, which may have had the potential to survive, will not be preserved for the next ash generation. This practically means that flood-plain forests like the one we visited, the ash population will extinct if the current trend continues. Consequently, this would trigger further serious problems for the entire ecosystem.
So, to get back to my initial question, how does the future of common ash looks like, also for the woodworking industry? The latest research is pessimistic. About 95% of ash trees will be completely eradicated in the future. The experienced forester that we had a chance to meet says that the ash forest in his area will disappear within 10 years.
Can human society do something about this issue or the ash tree will never be known by for the future generations?
1 For instance, available in Slovak: Poznatky z hynutia jaseňov Spôsobovaného hubou hymenoscyphus Pseudoalbidus, Masívne vymieranie jaseňov v Európe