sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

100 fascicle weight (g)
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SDÜ Faculty of Forestry Journal
Figure 3. Fascicle weights of healthy (h) and unhealthy (uh) pine needles in control (C),
thinning (T), pruning (P) and thinning plus pruning (TP) treatments.
4. CONCLUSION
h uh h uh h uh h uh
K T P TP
Diplodia had some very serious effects on pine stands of Asagi Gokdere region.
The symptoms diminished over the past four years since its first occurrence in this
site. The site characteristics indicated poor site with low nutrients and rocky soil.
Nutrient level in the needles also showed very low levels of N, indicating nitrogen
deficiency. In fact, N levels in needles were almost one half of the one in a healthy
needle. In addition, these stands have received no silvicultural treatments in recent
years and the number of stems in these stands was almost twice as much as it
should be.
Although the site is located in a region which receives approximately 1000 mm
rainfall, most of it is received in winter, and summer droughts are very common.
Temperatures reaching above 40°C during the summer months intensify the effects
of drought, creating a very high demand for evapotranspiration.
These poor site conditions and extreme droughts may have played a role in
development of the shoot blight in these stands. Apparently, the site was both
nutrient and water limited, especially during the growing season. This limitation
was most apparent when the canopy of the stand was investigated. In most areas of
the site, the individual trees had very thin and sparse canopy due to lack of growing
space and site resources to develop healthy crown (Figure 4). Timely and
appropriate silvicultural treatments may reduce the effects of poor soil conditions
and droughts, leading to stronger and more resistant trees beforehand, and better
recovery after an infection.
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