sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDU Faculty of Forestry Journal
Serial: A, Number: Special Issue, Year: 2009, ISSN: 1302-7085, Page: 245
PREMATURE DEFOLIATION OF Cedrus libani IN SOUTH-WESTERN
TURKEY
Asko Lehtijärvi 1* and H. Tuğba Doğmuş-Lehtijärvi 1
1 Süleyman Demirel University, Faculty of Forestry, 32260 Isparta, Turkey
*asko@orman.sdu.edu.tr
Cedrus libani A. Rich forests are presently found mainly in the Taurus
Mountains of Turkey while only small populations of the once extensive and
magnificent cedar forests remain in Lebanon and Syria. There are some 600 000 ha
of C. libani forests in Turkey, most of which are mixed stands. Wood of C. libani
is economically important as it is highly resistant to decay, durable and easy to
process by hand tools and machines. In addition to economical value C. libani
forests are significant from historical, cultural and aesthetic point of view, and
therefore actions for sustainable usage and restoring degraded stands have been
initiated.
In some C. libani stands in the lakes district of Turkey browning of needles
occurred in spring, especially in the lower part of the canopy. The disease was
observed both on saplings growing as understory in mixed forest as well as on
approximately 10–m–tall trees in an even–aged stand. A close investigation
revealed ascomata on 1–year–old needles still attached to the twigs. Often only the
ascomata-bearing part of the needle was brown while other parts had remained
green. In the lower part of the canopy of a sapling major part of the needles could
be diseased. On a single branch showing signs of serious premature defoliation
proportion of needles bearing ascomata was 49.3 % of the total dry weight of the
needles, while the corresponding value for more or less healthy needles was 37.4%.
Chlorotic or damaged needles without ascomata made up 13.2% of the total needle
dry weight.
The morphological characteristics of the ascomata were very similar to those of
Ploioderma cedri S. Singh, S.N. Khan & B. Misra occurring on C. deodara in
India, but asci and ascospores were somewhat larger. The frequent fruiting on dead
parts of an otherwise green needle indicates that the fungus is the causal agent of
the disease.
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