sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ Faculty of Forestry Journal
There are some differences in health condition among tree species. For
example, Siberian elm and black locust are very damaged as well as very abundant,
whereas cypress (Cupressus sp.), umbrella pine (Pinus pinea) and cedar (Cedrus
sp.) are very frequent but not so damaged.
The most important problem for Siberian elm is bad shaped trees. This term is
used to describe the plants with bad structured crowns or trunks, for example, those
trees with hanging small branches or leaning stems. Hanging branches seem to be
very common in this species (Saiz de Omeñaca and Prieto Rodríguez, 2004).
Dead branches are frequent for black locust, and this was also showed in
another survey (Rodríguez Barreal et al., 2000).
Box elder has stem wounds as its main problem. If this problem was associated
with decay it could make trees fail, since the wood of box elder is very susceptible
to decay and has a practical inability to close its wounds (Saiz de Omeñaca and
Prieto Rodríguez, 2004). Powdery mildew is found as well in some green spaces,
which is ordinary in this species (Saiz de Omeñaca and Prieto Rodríguez, 2004).
Anthracnose is observed in most of the green spaces where plane trees are
grown. This fungal disease is produced by Apiognomonia veneta (Sporonema
platani) and their first symptoms are not identified until the beginning of the 1970s
in central Spain (Tello et al., 2000). Since that moment, the presence of the fungi
has been known about in street trees in Madrid (Rodríguez Barreal, 1986). It
remains unclear whether it affects less its precursor Plantanus orientalis (Villalva
Quintana, 2005) than to the own hybrid (Rodríguez Barreal, 1986), although it
seems that “the different genotypes of the hybrids allow differences in disease
severity among trees growing under the same environmental conditions, though
eventually all trees are affected to some degree or another” (Tello et al., 2000).
The abundance of epicormic shoots and adventitious branches (3 rd and 4 th problem)
could be related to this disease, since the infestation of the fungi in adventitious
buds produces a much greater number of them (Tello et al.2000), however, it could
be also associated with the tendency to create them when the planting conditions of
plane trees are not appropriate (Saiz de Omeñaca and Prieto Rodríguez, 2004).
4.6 The most damaged shrub species are oleander, cotoneaster, Japanese
cheesewood and European spindle.
Oleander (Nerium oleander), cotoneaster (Cotoneaster sp.), Japanese
cheesewood (Pittosporum tobira) and European spindle (Euonymus europaeus) are
the most damaged species (Table 5).
Main problem of oleander is the bacteria Pseudomonas syringae subsp.
savastanoi, which affected about half of green spaces every year. The former
produces galls in flower buds, so those plants become weaker and with aesthetic
harms (Villalva Quintana, 2005). Dead plants are the principal problem affecting
cotoneaster and Japanese cheesewood, the second regarding European spindle, and
the third concerning oleander. Aphids were in more than 24% of SYGs of oleander,
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