sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ Faculty of Forestry Journal
F. ornus as well as the exotic F. pennsylvanica and F. americana (Kirisits, 2008;
Kirisits et al., 2008a; Kirisits and Cech, 2009).
The disease occurs on ash trees of all ages, both on natural regeneration and
planted trees and on the entire spectrum of sites and forest types, where ash is
found (Cech, 2008). Ash dieback is damaging on both forest and shade trees and it
also causes serious problems in nurseries, where rearing of healthy ash seedlings
has become difficult, if not impossible. In heavily affected forests mortality is
common amongst saplings and young trees. Moreover, in some areas dying of
mature trees has started to occur. It is expected that the future use of F. excelsior as
economically and ecologically valuable noble hardwood species will be
substantially impaired by this emerging disease.
Figure 2. Symptoms of ash dieback: (A) Wilting of leaves due to girdling of the phloem
and sapwood occlusion, (B) A necrotic lesion in the bark with a small dead twig in the
centre, (C) A necrotic lesionr in the bark with a leaf scar (arrow) in the centre, (D)
Discoloration of the wood.
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