Current tables of wood assortments for the most important tree species in B&H were made almost 50 years ago. There is an indication that real forest wood assortments are different than the one derived from assortment tables in-use, both in terms of quality and dimensions. In the meantime, from the creation of the existing tables until today, the standards of production of forest wood assortments have changed, so that the fact of inaccuracy of the existing assortment tables is unquestionable. This continually creates a variety of problems in the ongoing operations of forestry companies. The main aim of this paper is to create wood assortment tables whose assortment of wood products will correlate with the current market conditions. The research was conducted in the area of the Canton 10 in FB&H.  A sample of 393 spruce trees was used as a database to produce this paper. The bucking of the sample trees was carried out in accordance with the valid norms and customer requirements with regards to the dimensions of forest wood products. Data processing was performed using methods of simple and multiple regressions, variance analysis as well as their combinations by the Generalized Linear Models method. Independent factors were breast diameter (DBH), technical quality class and the height of the trees. The share of wood assortments was determined through 10 different mathematical models, and it was found that all independent variables had a statistically significant influence on the dependent variables- volume of particular assortments or group of assortments. The share of logs is growing rapidly with the increase of tree diameter and decreases with decreasing of their technical quality. The influence of tree height primarily correlated with tree volume increase. Trees having better assortment quality, have tree heights higher than average for the same diameter class. The results of the research are presented in the form of tables as percentage share of wood assortment classes.  The obtained results can be used as wood assortment tables in the research area.

U radu su korišteni podaci izmjere 377 modelnih stabala smreke koja su mjerena u oborenom stanju na širem području unutar državnih raznodobnih sastojina u Kantonu 10 (Hercegbosanski Kanton). Za određivanje volumena krupnog drveta stabala primijenjena je metoda sekcioniranja sa sekcijama nejednakih apsolutnih dužina (najčešće od 1 – 2 m). Za izravnanje veličina volumena krupnog drveta od prsnog promjera i visine stabala primijenjena je metoda višestruke regresijske analize. Za procjenu parametara korištenih funkcija, testiranje značajnosti njihovih razlika te provođenje raznih transformacija, kao softversko rješenje korišteni su StatGraphics Centurion XVII. i Statistica 8.0. U cilju izbora „najboljeg“ modela za procjenu volumena krupnog drveta testiran je veći broj poznatih dendrometrijskih dvoparametarskih volumnih funkcija. Kvaliteta izjednačenja i prikladnost testiranih modela ocjenjivani su na bazi utvrđenih veličina osnovnih statističkih pokazatelja za karakteriziranje jačine korelacijskih veza. Najbolje ocjene parametara pokazao je model V7=a0+a1d1,3+a2h+a3d1,3h+a4d1,32+a5 d1,32h uz utvrđeni koeficijent determinacije: R2 = 0,99 i veličinu standardne greške regresije Sey=0,24 m3. Testirajući značajnost razlika između stvarnih volumena stabala iz uzorka i volumena tih istih stabala utvrđenih primjenom odabranog regresijskog modela, utvrđen je prosječni postotak odstupanja od 0,44%. To znači da su u prosjeku za 0,44% niži volumeni u odnosu na stvarne volumene na uzorku od 377 stabala smreke, što ukazuje da je ovaj regresijski model upotrebljiv za primjenu u praktičnom radu, jer je taj prosječni postotak manji od 1%.

Utvrđivanje kapaciteta proizvodnje sekundarnih energenata na podrucju Tuzlanskog kantona pružavažno uporiste za detaljnije i racionalnije planiranje koristenja drvnog otpada iz razlicitih izvora kojinastaje na navedenom podrucju. Za potrebe ovih istraživanja koristena je metoda analize i sinteze,kao i komparativna analiza na osnovu izvora podataka dobijenih od vlasnika postrojenja za proizvodnjusekundarnih energenata, drvoprerađivackih preduzeca i preduzeca koje gazduje sumama Tuzlanskogkantona, ostale relevantne dokumentacije iz Kantonalne privredne komore Tuzla, te na osnovuIzvjestaja o poslovanju i statistickih biltena. Trenutno je iskoristeno 59% kapaciteta postrojenja zaproizvodnju peleta na Tuzlanskom kantonu, proizvodnja briketa se realizuje sa 77%, a drvna sjeckasa 70%. Kolicina drvnog otpada iz prerade drveta iznosi cca 36 306 m³ godisnje. Stvarna realizacijaogrevnog drveta sa maloprodajom na podrucju Suma TK iznosila je 96.007 m3. Na podrucju Tuzlanskogkantona postoje prerađivaci (cijepanje) drveta sa 43% iskoristenog kapaciteta. Rezultati rada pokazujuda se potencijal proizvodnje sekundarnih energenata na podrucju Tuzlanskog kantona ne koristina zadovoljavajucem nivou. Maksimalni kapaciteti proizvodnje se ni približno ne ostvaruju. Da bi seosigurala isplativa i održiva proizvodnja peleta i briketa, osnovni uslov je da se raspolaže potrebnimkolicinama sirovine. Ukupna kolicina otpadnog drveta na podrucju Tuzlanskog kantona nije dovoljnaza maksimalni kapacitet instalisanih postrojenja za proizvodnju sekundarnih energenata. U tom slucajuneophodna je nabavka sirovine sa sireg podrucja BiH, zatim bolje koristenje otpada iz sumarstva, anarocito koristenje izdanackih suma. Kao sirovinska baza tu je svakako i mogucnost proizvodnje energetskihplantaža brzorastucih vrsta i sl.

In Europe, mixed mountain forests, primarily comprised of Norway spruce (Picea abies (L.) Karst.), silver fir (Abies alba Mill.), and European beech (Fagus sylvatica L.), cover about 10 × 106 ha at elevations between ∼600 and 1600 m a.s.l. These forests provide invaluable ecosystem services. However, the growth of these forests and the competition among their main species are expected to be strongly affected by climate warming. In this study, we analyzed the growth development of spruce, fir, and beech in moist mixed mountain forests in Europe over the last 300 years. Based on tree-ring analyses on long-term observational plots, we found for all three species (i) a nondecelerating, linear diameter growth trend spanning more than 300 years; (ii) increased growth levels and trends, the latter being particularly pronounced for fir and beech; and (iii) an elevation-dependent change of fir and beech growth. Whereas in the past, the growth was highest at lower elevations, today’s growth is superior at higher elevations. This spatiotemporal pattern indicates significant changes in the growth and interspecific competition at the expense of spruce in mixed mountain forests. We discuss possible causes, consequences, and silvicultural implications of these distinct growth changes in mixed mountain forests.

Mixed mountain forests of European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst), and silver fir (Abies alba Mill.) cover a total area of more than 10 million hectares in Europe. Due to altitudinal zoning, these forests are particularly vulnerable to climate change. However, as little is known about the long-term development of the productivity and the adaptation and mitigation potential of these forest systems in Europe, reliable information on productivity is required for sustainable forest management. Using generalized additive mixed models this study investigated 60 long-term experimental plots and provides information about the productivity of mixed mountain forests across a variety of European mountain areas in a standardized way for the first time. The average periodic annual volume increment (PAI) of these forests amounts to 9.3 m3ha−1y−1. Despite a significant increase in annual mean temperature the PAI has not changed significantly over the last 30 years. However, at the species level, we found significant changes in the growth dynamics. While beech had a PAI of 8.2 m3ha−1y−1 over the entire period (1980–2010), the PAI of spruce dropped significantly from 14.2 to 10.8 m3ha−1y−1, and the PAI of fir rose significantly from 7.2 to 11.3 m3ha−1y−1. Consequently, we observed stable stand volume increments in relation to climate change.

Background and Purpose: Bark thickness and its share in the volume of roundwood are the most important characteristics of the bark, particularly in the process of timber harvesting, and during scaling of processed logs. Therefore it is very important to have at disposal relatively accurate data regarding these characteristics of bark for particular tree species. The main goal of this paper is to investigate the thickness of the bark and its share in the volume of roundwood of Norway spruce. Materials and Methods: The research was carried out in the area of the Canton 10 of the Federation of Bosnia and Herzegovina and it encompassed 393 trees of Norway spruce from 10 cm to 115 cm of thickness at breast height. Measuring of the mean diameter and double thickness of bark was conducted by section method. In total, 4,647 diameters and bark thicknesses were measured in different relative lengths of stems or in average 10.6 measurements per one stem. Results: As an optimal model for the evaluation of double thickness of the bark of Norway spruce depending on mean diameter of roundwood the function with designated determination coefficient of 0.7142 was selected. The obtained results have confirmed the previously defined relations of investigate characteristics, which are as following: a) with the increase of mean diameter of roundwood (section) double bark thickness is increased from 9.26 mm (thickness class 12.5 cm) to 31.65 mm (thickness class 92.5 cm); b) with the increase of mean diameter of roundwood the share of bark in its volume decreased from 14.26% (thickness class 12.5 cm) to 6.73% (thickness class 92.5 cm). Conclusions: By the actual method of estimating bark thickness or the share of bark in the volume of roundwood of Norway spruce in the forestry of the Federation of Bosnia and Herzegovina a significant error was created which increases with the increase of mean diameter. The obtained results point to the necessity of investigation of these bark characteristics in Bosnia and Herzegovina and represent an inevitable starting point for making adequate tables of bark thickness and its percentage share in the volume of roundwood of Norway spruce.

Utvrđivanje kapaciteta proizvodnje sekundarnih energenata na području Tuzlanskog kantona pruža važno uporište za detaljnije i racionalnije planiranje korištenja drvnog otpada iz različitih izvora koji nastaje na navedenom području. Za potrebe ovih istraživanja korištena je metoda analize i sinteze, kao i komparativna analiza na osnovu izvora podataka dobijenih od vlasnika postrojenja za proizvodnju sekundarnih energenata, drvoprerađivačkih preduzeća i preduzeća koje gazduje šumama Tuzlanskog kantona, ostale relevantne dokumentacije iz Kantonalne privredne komore Tuzla, te na osnovu Izvještaja o poslovanju i statističkih biltena. Trenutno je iskorišteno 59% kapaciteta postrojenja za proizvodnju peleta na Tuzlanskom kantonu, proizvodnja briketa se realizuje sa 77%, a drvna sječka sa 70%. Količina drvnog otpada iz prerade drveta iznosi cca 36 306 m3 godišnje. Stvarna realizacija ogrevnog drveta sa maloprodajom na području Šuma TK iznosila je 96.007 m3. Na području Tuzlanskog kantona postoje prerađivači (cijepanje) drveta sa 43% iskorištenog kapaciteta. Rezultati rada pokazuju da se potencijal proizvodnje sekundarnih energenata na području Tuzlanskog kantona ne koristi na zadovoljavajućem nivou. Maksimalni kapaciteti proizvodnje se ni približno ne ostvaruju. Da bi se osigurala isplativa i održiva proizvodnja peleta i briketa, osnovni uslov je da se raspolaže potrebnim količinama sirovine. Ukupna količina otpadnog drveta na području Tuzlanskog kantona nije dovoljna za maksimalni kapacitet instalisanih postrojenja za proizvodnju sekundarnih energenata. U tom slučaju neophodna je nabavka sirovine sa šireg područja BiH, zatim bolje korištenje otpada iz šumarstva, a naročito korištenje izdanačkih šuma. Kao sirovinska baza tu je svakako i mogućnost proizvodnje energetskih plantaža brzorastućih vrsta i sl.

UDK: 630*54:582.475(497.6) In expert activities of forest managements, the forest stand volume is most frequently determined by way of volume tables, the so-called management tariffs. For an evaluation of stand volume using this method, the method of volume tables, it is necessary to know the site class (rating) of the stand for present tree species that is used as an argument for the selection of suitable volume progression (management tariff). The site quality for certain species in mixed stands is determined by comparing the height of trees at certain diameters at breast height (dbh) with the height of appropriate dispositions of height site class curves. In so doing the focus is placed on the ratio between the heights of large diameter trees, and the quality of the stand is rated within an interval of more defined site quality classes. For the purposes of a more objective and simpler  assessment of site quality, there have recently been attempts to make site quality assessments mathematically, using appropriate formulas in which tree heights or average heights by diameter classes and heights determined by mathematical functions of site class curves are used. For economically important tree species in Bosnia and Herzegovina (fir, spruce, beech, sessile oak, black pine and scots pine), the dispositions of height site class curves (and classes) are constructed graphically and mathematical functions for them are not known. A large number of mathematical models that are often used to represent growth trends and that satisfy the needs of height curves is analyzed in this paper with a view to determining the most suitable regression model for simulating height site class curves for fir in high forests in Bosnia and Herzegovina. The expanded Prodan model (with an additional item in the denominator) has been selected as the most suitable one on the basis of statistical indicators of the regression model quality.