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ŠUMARSKI LIST 9-10/1957 str. 41     <-- 41 -->        PDF

SUMMARY


In this paper are described the results of investigation into the technical properties
of Slavonian oak wood. In all, there were investigated 59 sample trees of
Slavonian oak, i. e. 43 of Pedunculate oak (Quercus pedunculata Ehrh.), 15 of Sessile
oak (Quercus sessiliflora Salisb.) and 1 of Hungarian oak (Quercus conferta Kitaibel).


The aim of this investigation was: a) to examine some technical properties of
Slavonian oak wood from Yugoslav forests, b) to establish differences between the
technical properties of Pedunculate and Sessile oak wood, c) to establish differences
between young and old Slavonian oak wood.


Thus far the technical properties of Slavonian oak wood from Yugoslav forests
have not been investigated. In the introduction to this paper the´ results of the
researches undertaken so far by Bogner (1861), Kesterčanek (1880), Janka (1915),
Ugrenović (1940, 1941, 1942) and Horvat (1942) are analysed. The data given in these
papers on the technical properties of Slavonian oak wood are incomplete in many
respects. The investigations referred to some technical properties (Ugrenović, Horvat)
as well as the specimens concerned are relatively few in number (Bogner, Kesterčanek,
Janka).


The sample trees of Pedunculate oak were selected from stands in Slavonian
forest districts Topolovac (1 sample tree), Lipovljani (20), Novska (2), Banova Jaruga
(3), Rajevo selo (2), Vrbanja (1), Morović (2), Klenak (2), Ogar /3/, anđ Kupinovo
(3 sample trees); from the stands in forest districts Pitomaca (2 samples trees), Tikveš
(1), and B. Manastir (1). The sample trees of Sessile oak were selected from the
stands in the forest districts of Kostajnica (5 sample trees), Rujevac (4), N. Gradiška


(4)
and Srem. Kamenica (2).
From the sample sections were made and examined 1905 specimens. The annual-
ring width, late-wood, specific gravity of air-dry wood, specific gravity of oven-
dry wood, nominal specific gravity (weight oven-dry, volume green), radial and
tangential shrinkage, shrinkage in volume and moisture content of wood were
measured and examined in 601 specimens; the compressive strength was examined
in 518 specimens, static bending strength in 376, and impact bending strength in 410
specimens. 1270 specimens were made from Pedunculate oak wood, 620 from Sessile
oak wood, and 15 from Hungarian oak wood.
On the basis of these investigations it is possible to draw the following conclusions:


1. The annual-ring width varied from 0.83 to 5.37 mm, (mean 1.98 mm) (see
Tabs. 2, 3 and Fig. 2); the late-wood from 39 to 96°/o (mean 67.3°/«). The annual-ring
width of Pedunculate oak wood (2.02 mm) is a little greater than that of Sessile oak
wood (1.85 mm). The late-wood "/o of Pedunculate oak (67.1´/») is a little lower than
that of Sessile oak (68.6).
2. The specific gravity of Slavonian oak wood, air-dry, varies from 0.438 to
0.861 g./cu. cm. (mean 0.678 g./cu. cm.) (see Tabs. 2 and 5); the specific gravity of
Slavonian oak wood, oven-dry, from 0.388 to 0.837 o./cu. cm. (mean 0.635 g./cu. cm.)
(see Tabs. 2, 4 and Fig. 4); the nominal specific gravity from 0.353 to 0.706 g./cu. cm.)
(mean 0.555 g./cu. cm.) (see Tabs. 2, 6 and Fig. 4). The specific gravity of Pedunculate
oak wood (0.670, 0.625 and 0.535 g./cu. cm.) is lower than that of Sessile oak wood
(0.700, 0.662 and 0.570 g./cu. cm. respectively).