|ORIGINAL SCIENTIFIC PAPERS|
|Pilaš, I., Seletković, A.||UDK 630* 181.3 + 581|
|An Analysis of Groundwater Regime of Lowland Našice Forest Area by Use of Grass Gis pdf HR EN||363|
|Trinajstić, I.||UDK 630* 188|
|Nomenclatural and Syntaxonomic Revision of the Complex “Blechno-Fagetum (Ht. 1950) Ex Marinček 1970” (Luzulo-Fagion) pdf HR EN||375|
|Zečić, Ž., Poršinsky, T., Šušnjar, M.||UDK 630* 305 + 242|
|Some Harvesting Results in Hilly Thinning Stands by Group Labor With a Review of Selection of Time Study Method pdf HR EN||381|
|Prka, M.||UDK 630* 523 (Fagus sylvatica L.)|
|Bark Thicknees of Common Beech (Fagus sylvatica L.) in Cutting Areas of Bilogora near Bjelovar pdf HR EN||391|
|Summary: Smooth and thin bark is one of very prominent morphological features of common beech. Because of particular activity of cork cambium (phellogen) beech bark follows thickness increment, and it does not peel off and crack on the surface.Research of bark of domestic tree species in Croatia started in the 1850s, and in the beginning, species with thicker bark attracted more attention.|
Structure and appearance of bark often vary considerably, even in trees of the same species, if they grow in different conditions. Specific features of bark variability are genetically determined. Researching bark thickness of beech trees in the area of Bjelovar Bilogora, we noticed specific variability in beech bark morphology.
Empiric cognitions of forestry operational bodies in the researched area tell us that beech trees with furrowed (rough) bark are less inclined towards creating false heartwood (kern). That assumption has not been tested primarily because of small number of such trees in the researched area.
Of all the bark features, the most important is its thickness. That results from the fact that we produce technical roundwood of foliaceous trees, pull it and transport it with bark, but we measure it (take it over) and ship it without bark. In that way, bark of foliaceous trees in technical roundwood is specific ballast in production, which does not give financial results.
So far, research of beech bark thickness (Krpan, 1986) has established some generally accepted regularities:
– Bark thickness is in direct relation to tree or roundwood diameter.
– Bark thickness decreases from the tree stump towards the top of the tree trunk.
– Bark thickness increases with roundwood thickness, while the percentage of thickness and the volume decrease.
Also, poor natural settings cause greater bark thickness.
Double bark thickness was measured at breast level of the tree, then in the middle of each log, and in the middle of every fifth round log of firewood. Bark sample was taken from the specified places by a little axe, to make sure it is big enough and to avoid its bruising. Bark thickness was measured by micrometer calliper with nonius correct at 0.1 mm. Total bark thickness value was obtained by adding the measured values of bark thickness in samples taken from the opposite places on the roundwood cover.
The research included 2,106 sample trees on 30 research objects in total number of 34 occasions (fellings), with 18,381 pairs were measured for double bark thickness and breast diameter, or diameter in the middle of the item.
We researched bark thickness in relation to common beech diameter in thinning and seeding fellings of beech-cutting areas in the economic unit Bjelovarska Bilogora. We analysed the average percentage of bark in the volume of technical roundwood, with regard to type of felling of seeding beech fellings.
Data on double bark thickness in relation to breast level diameter of the tree were equalized by regressive linear equation with very strong correlation. Values of double bark thickness in relation to diameter in the middle of technical roundwood and round logs were equalized according to type of felling by regressive linear equations with strong and very strong correlations.
It has been established that there are not any significant differences between the values of double bark thickness in relation to thinning, preparatory, seeding and final felling, so that the values of double bark thickness and the diameter of the whole sample were equalized by the following linear equation: y = 0.0134 x + 0.4123
The research confirmed the regularities defined in previous research. Furthermore, the absolute values of bark thickness in relation to diameter and average percentages of bark in technical roundwood are smaller then established in the previous research. That confirms the thesis that poor natural settings determine greater bark thickness, having in mind the differences in height above sea-level between the objects of this and the previous research.
We established percentages of bark in volume of technical roundwood of 5.1 % in preparatory felling, 4.8 % in seeding felling and 4.7 % in final felling. For the sample of 693 sample trees in seeding felling the average percentage of bark in technical roundwood, calculated according to wood bulk with bark was 4.8 %.
The results of the research were compared to the results of the previous research carried out in NPŠO Velika (Krpan, 1986), and to usance applied in beech forest wood products, and significant differences were established.
Key words: bark thickness; beech felling; Bjelovarska Bilogora; common beech
|Krejči, V., Dubravac, T.||UDK 630* 231 + 226 (Quercus ilex L.)|
|From Coppice Wood to High Forest of Evergreen Oak (Quercus Ilex L.) by Shelterwood Cutting pdf HR EN||405|
|Crnković, S.||UDK 630* 232.3 (Quercus robur L.)|
|Quantitative and Qualitative Properties of Common Oak Acorn (Quercus robur L.) in the Stands of the Basin of the Česma River pdf HR EN||413|
|Zelić, J.||UDK 630* 525 (quercus frainetto ten)|
|Preliminary Sortiment Tables for Italian Oak (Quercus Frainetto Ten) pdf HR EN||431|