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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*
upute autorima


Parafiscal levies – definition and who should pay them     pdf     HR     EN 337
Milan Pernek, Marta Kovač, Nikola Lacković UDK 630* 453 (001)
Testing of biological effectiveness of pheromones and traps for catch of mediterranean bark beetle Orthotomicus erosus (Coleoptera, Curculionidae)     pdf     HR     EN 339
Mladen Ognjenović, Tom Levanič, Nenad Potočić, Damir Ugarković, Krunoslav Indir, Ivan Seletković UDK 630* 425 + 111 (001)
Interrelations of various tree vitality indicators and their reaction to climatic conditions on a european beech (Fagus sylvatica L.) plot     pdf     HR     EN 351
Simon Lendvai, Jurij Diaci, Dušan Roženbergar UDK 630* 242 (001)
Response of black alder (Alnus glutinosa (L.) Gaertn.) to selective thinning of various intensities: a half-century study in northeastern Slovenia     pdf     HR     EN 367
Besim Balić, Ante Seletković, Ahmet Lojo, Aida Ibrahimspahić, Jusuf Musić, Admir Avdagić, Velid Halilović UDK 630* 516 (001)
Model for estimation merchantable wood volume of spruce (Picea abies Karst) in Canton 10, Federation of Bosnia and Herzegovina     pdf     HR     EN 379
For assessment of growing stock in B&H forestry praxis as scientific baseline we are using volume tables and tariffs (Drinići dr. 1990). Having in mind the fact that these are constructed based on volume coefficients of the trees taken from German tree volume tables, which originate from single-age assortments, it is justified to suspect that by applying these tables one will get certain differences in quantity of large wood mass related to the actual status of those volumes. It is known that trees of the same tree species coming from single-age assortments are more full-bodied because they have larger volume coefficients compared to the trees of the same species from variable aged and selection forest assortments. That is why the objective of this research is to find “the best” regression model for levelling of volume of large wood of spruce, as dependent variable depending on diameter at breast height and tree height, as independent variables. To achieve this objective we have selected 377 model trees of spruce that were measured in felled condition on wider area of state owned variable aged assortments in Canton 10 (Livno Canton). To determine volume of large wood of trees we applied section method with sections of uneven absolute lengths (most often from 1 – 2 m). For levelling of volumes of large wood depending on diameter at breast height and tree height we applied method of multi-regression analysis. Quality of levelling and appropriateness of tested models was evaluated on the basis of determined values of basic statistical indicators for characterisation of the strength of correlation connections. The best values of the parameters showed model: V7=a0+a1d1,3+a2h+a3d1,3h+a4d1,32+a5 d1,32h with determined determination coefficient: R2 = 0,99 and size of standard regression error: Sey=0,245 m3. By testing significance of differences between actual/real tree volumes from the sample and volume of those trees determined by application of selected regression model by using t-test of pairs, no statistically significant differences were recorded. Average percentage of deviation was -0.44%. That means that in average we get 0.44% lower volumes comparing to the actual volumes in the sample of 377 spruce trees which shows that this regression model is usable for application in practice, because that average percentage is less than 1%. Statistically significant differences were recorded between volumes of trees of selected regression model and volume tables and models of other authors (Stojanović i dr. 1978; Banković i dr. 2003; Špiranec, 1976.). Those deviations vary in the range from 2.53% up to 22.7%. The largest deviations were determined exactly in model that is used in B&H (Stojanović i dr. 1978) and are in amount of 22.7% while the lower deviations were determined for volumes estimated by using model created for spruce trees from Sub-Alpine belt for area of Kopaonik (Banković i dr. 2003) and those amount to 2.53%.

Key words: spruce; merchantable wood volume; regression model; nonlinear regression; two-entry volume tables
Hüseyin Ogfuz Çoban, Halis Bereket UDK 630* 432 (001
Visibility analysis of fire lookout towers protecting the Mediterranean forest ecosystems in Turkey     pdf     HR     EN 393
Željko Španjol, Boris Dorbić, Nikola Vrh, Ivana Gašparović, Ivan Tolić, Milan Vojinović UDK 630* 187 + 174
Vegetative and dendrological characteristics of Hober forest park in Korčula     pdf     HR     EN 409

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