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Znanstveno-stručno i staleško glasilo
Hrvatskoga šumarskoga društva
Journal of Forestry Society of Croatia
      Prvi puta izašao 1877. godine i neprekidno izlazi do današnjeg dana
   ISSN No.: 0373-1332              UDC 630* https://doi.org/10.31298/sl
upute autorima
WEB EDITION
ARHIVA ČASOPISA


HRČAK


 
PRELIMINARY COMMUNICATION
     
Prpić, B., Seletković, Z., Tikvić, I. UDK 630* 919 + 171.3 (001)
On the Influence of the Sava - Danube Canal on Forest Ecosystems     pdf     HR     EN 579
 
ORIGINAL SCIENTIFIC PAPERS
     
Trinajstić, I., Franjić, J., Samardžić, I. UDK 630* 181.1 + 188 : 630* 173.5 + 174.7 (Abies alba Mill.) 001.
About the Importance of the Discovery of the Species Equisetum sylvaticum L. (Equisetaceae) for Understanding the Autochthonism of the Silver Fir (Abies alba Mill, Pinaceae) in Požeško gorje     pdf     HR     EN 593
Franjić, J., Škvorc, Ž. UDK 630* 422 (Quercus Cerris L) 001.
Frost-crack in Some Oak Species (Quercus L., Fagaceae) on Krndija and Dilj (Slavonia, Croatia)     pdf     HR     EN 599
Summary: Frost-crack is aphenomenon occurring on woody species in ali areas of
the Northern Hemisphere with a distinct hibernalperiod. Its intensity, namely its significance
with respect to the forestry and economy as well as the ecology varies depending
upon climatic conditions, tree species, etc. Damages caused by the frost-crack are considerable
because it does not only damage the lower, economically the most valuable
part ofthe tree trunk, but also increases the possibility for a large number ofpathogenic
organisms to penetrate into trees. The frost-crack is a very complex phenomenon and
most likelv there is not onefactor which can be generalized as its only and main cause,
but like ali other phenomena in the ecosystem it results from the interaction of many
complicated and often hardly understandable processes in them. The most acceptable
theoryfor crack formation in the tree trunk lower parts is the one by which formation of
cracks is connected with abrupt and high drops in air temperature, that causesfast cooling
and shrinking oftree trunk outer lavers while the inner ones cool very slowly and,
therefore, keep their dimensions for a longer time period. As the result, in the outer parts
ofa tree trunk there appear tangentialforces which act in two different directions causing
cracking. The frost-crack, therefore, occurs as the consequence ofbad thermal conductivity
ofwood.

The researches ofthe frost-crack on the turkey oak, sessile oak and common oak trees
have been carried out in four populations (Kutjevo, Caglin, Rozmajerovac, Levanjska
Varoš) on seven trialplots.

The average share of frost-cracked sessile oak trees in pure stands is 3.67 % (2 -7%),
whilein the mixedstands with the turkey oak this share is 14.67 % (10-20 %), thatis approximately
4 times more (tab. 2). The average share of frost-cracked turkey oak trees in
the mixed sessile oak and turkey oak stands is 53 % (43 -64%). This frequency is in the
average about 3.5 times higher for the turkey oak thanfor the sessile oak in the same
stands. The frost-crack ofthe common oak in the Rozmajerovac population (the common
oak with the turkey oak) is 8 %, and that ofthe turkey oak 50 %, showing that the sessile
oak is much more susceptible to damage by frost-crack than the common oak (tab. 2).

The share of the frost-cracked turkey oak trees changes with a change of exposition,
thus it is the biggest (64%) on the North-East exposition (N-E) and the smallest (43%) on
the South-East one (S-E), (tab. 3).

From the figure 1 it can be seen that according to thicknesses grades the share of
frost-cracked turkey oak trees increases with the thickness grade increase in three out of
four researchedpopulations (Čaglin, Rozmajerovac, Levanjska Varoš) while only in the
Kutjevo population it decreases.

Using the statistical and graphical analysis, a general (preliminary) pattern ofthe
share offrost-cracked turkey oak trees in the mixed sessile oak and turkey oak stands has
been obtained, with a slower the frost-crack share growth due to the inclusion of the
Kutjevo population in which because ofthe recently performed thinning this share is decreased
(comp. fig. 5). Thus, with regard to the straight Une inclination, the Kutjevo population
differs significantly from other researched populations, among which no significant
differences exist (tab. 4). The share of the frost-cracked turkey oak trees grows

faster, with respect to the thickness growth, in the mixed common oak and turkey oak
štand than in the mixed sessile oak and turkey oak stands (fig. 5), mostprobably due to
the habitat characteristics (more moisture, morefrequentfrosts).

The researches have shown that there are thick turkev oak trees which are not frost-
cracked and which have a tree-trunk ofgood quality. The question is very likely about the
genotypes resistant to frost-crack which should be preserved by means of silvicultural
operations until the end ofrotation while the damaged and non-resistant trees should be
eliminated before regeneration. This can be considered only if because of the štand
structure or for any other reasons, the turkey oak cannot be eliminated from the sessile
oak stands, since not only itperishes by the frost-crack but it also transfers this inferior
property ofits to the sessile oak and the common oak with which it grows together in the
researched area.
 
REVIEWS
     
Pičman, D., Pentek, T., Mikić, B. UDK 630* 686 + 383 (001)
The use of Personal Computers in Planning and Drawing up Plans for Forest Roads     pdf     HR     EN 609
Turkulin, H., Jirouš-Rajković, V., Grbac, I. UDK 634.0 814.1 + 634.0 842 (001)
Surface Durability of the Wood Building Constructions     pdf     HR     EN 617
Piškorić, O. UDK 630* 902 (001)
´Works´ - a Magazine of the Croatian-Slavonian Management Society 1847 - 1852     pdf     HR     EN 631
 
PROFESSIONAL PAPERS
     
Rauš, Đ., Španjol, Ž., Španjol, B. UDK 630* 188 + 249 : 630* 156 (Quercus ilex L.)
Scientific and research work in the educational-experimental forest facility of Rab     pdf     HR     EN 645
Dimitrov, T. UDK 630* 432.0
History of the Canadian Forest Fire Danger Evaluation System Development and the Possibility of its Application in Other Countries     pdf     HR     EN 657

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