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.
Ozljede na radu i profesionalne bolesti radnika pouzdan su indikator procjene stanja sigurnosti pri radu. Osnovni je cilj ovoga rada odgovarajuća analiza stanja sigurnosti pri radu u Javnom poduzeću ...Šumsko-privredno društvo Zeničko-dobojskoga kantona d.o.o. Zavidovići. Predmet su analize bile ozljede na radu, profesionalne i druge bolesti šumarskih radnika u razdoblju od 2006. do 2015. godine. Ozljede su analizirane prema deset pokazatelja. U analiziranom razdoblju zabilježene su 594 ozljede na radu, od čega tri smrtna slučaja. Najviše ozljeda dogodilo se neposrednim izvršiteljima radnih operacija pridobivanja drva (66,3 %), a najrizičnija je profesija sjekač (57,7 %). Predmet rada (drvo i grane) bili su najčešći materijalni uzrok ozljeda (49,3 %), a najčešće su ozlijeđeni ekstremiteti radnika – noge i ruke (70 %). Najveći broj ozljeda zabilježen je početkom radnoga tjedna i dana. Na osnovi broja ozljeda po obujmu izrađenoga drva (314/mil. m3) te indeksa od 60 ozljeda na 1000 zaposlenika stanje sigurnosti pri radu može se ocijeniti kao iznimno nezadovoljavajuće.
Injuries at work and occupational diseases are a reliable indicator for assessing the state of occupational safety. The aim of this paper was to conduct an appropriate analysis of the state of safety at work in JP Šumsko privredno društvo Zeničko-dobojskoga kantona d.o.o. Zavidovići (Public Forest Management Company of Zenica-Doboj Canton ltd. Zavidovići). The subject of analysis were injuries at work, occupational and other diseases of forestry workers in the period 2006-2015. Injuries were analyzed based on 10 different indicators. During the analyzed period, 594 injuries were reported, three of which were fatal. The highest number of accidents was recorded in the harvesting process (66.3%), while the most hazardous occupation was that of timber cutter (57.7%). Wood and branches were the most common material cause of injury (49.3 %), and workers’ extremities (legs and arms) were the most commonly injured body part (70%). The highest number of injuries was recorded at the beginning of the working week and day. According to the number of injuries by the amount of cut wood (314/mil. m3), as well as an index of 60 injuries per 1,000, employees safety at work can be assessed as extremely unsatisfactory.
Debljina kore i njen udio u obujmu oblog drva predstavljaju bitne značajke u tehnološkom procesu pridobivanja drva, posebno u fazi preuzimanja drva. S obzirom da je itekako važno raspolagati s ...relativno to
č
nim podacima ovih značajki kore za pojedine vrste drveća, osnovni cilj ovoga rada je istražiti navedene značajke kore bukve. Istraživanje je provedeno na području Kantona 10, a obuhvatilo je 678 stabla bukve od 10 do 85 cm promjera na prsnoj visini i od 5 do 40 m visine. Mjerenje srednjeg promjera i debljine kore obavljeno je metodom sekcioniranja, a ukupno je izmjereno 6.403 promjera i debljina kore ili 9,4 mjerenja po jednom stablu u prosjeku. Rezultati su pokazali sljedeće: a) povećanjem srednjeg promjera oblog drva dvostruka debljina kore povećava se od 6,05 mm (debljinski razred 12,5 cm) do 20,69 mm (debljinski razred 82,5 cm); b) povećanjem srednjeg promjera oblog drva udio se kore u obujmu eksponencijalno smanjuje od 9,44% (debljinski razred 12,5 cm) do 4,95% (debljinski razred 82,5 cm). Utvrđene razlike u komparaciji s drugim autorima koji su istraživali ove značajke kore bukve, ukazuju na važnost nastavka istraživanja i na drugim područjima u BiH. Na taj način bi se dobili pouzdaniji rezultati koji bi bili primjenjivi za cijelu državu ili parcijalno za pojedine njene dijelove, ako se razlika između područja pokaže statistički značajnom. Dobiveni rezultati predstavljaju nezaobilaznu polaznu osnovu za izradu tablica kore bukve i novog pravilnika o načinu izmjere oblog drva i utvrđivanja količina.
Thickness and share in volume of tree and/or round wood represent the most important features of the bark, especially in the process of timber harvesting, during scaling of processed logs. In forestry of Federation of B&H there are no rules or tables for deduction of double bark thickness based on scientific research. Wood assortments tables for our most important tree species, besides a whole series of wood assortments, also contain the category of waste. From a practical point of view this category can be divided into “real waste” and losses. The real waste in this sense consists of various logging slash and sawdust, while the loss constitutes a prescribed method of measuring the dimensions and calculation of volume and the deduction of the double bark thickness. So, it is very important to have relatively accurate data of the bark thickness for certain tree species. Therefore, the objecti ve of this paper is to explore double bark thickness and share of bark in the volume of beech round wood. The research was carried out in the area of the Canton 10 of Federation of B&H. The research included 678 sample trees from 10 cm to 85 cm diameter breast height (DBH) and from 5 m to 40 m of height with 6,403 pairs were measured for double bark thickness and diameter in the middle of the round wood (section). Data of double bark thickness in relation to mid diameter of round wood were equalized by following equation with coefficient of determination R2=0.722.
The results of research confirmed the regularities defined in previous research and has shown as follows: a) by the increase of mid diameter of round wood, double bark thickness increases from 6.05 mm (thickness class 12.5 cm) to 20.69 mm (thickness class 82.5 cm), b) by the increase of mid diameter of round wood, bark share in the volume decrease exponentially from 9.44 % (thickness class 12.5 cm) to 4.95 % (thickness class 82.5 cm).The research have indicated the need to use the results and incorporating it into applicable rules of deducting the bark on logs or share of bark in the volume depending on diameter over the bark.
Virgin forests are relatively rare in the European temperate zone. This is due to the continuous use of forest historically and to increasing high population densities. Virgin forests are forest ...where the structure and dynamics have developed entirely under natural conditions, without any human interference or influence. This article assesses the Pljesevica forest in Bosnia Herzegovina to establish whether it can be classified as virgin forest. The structure and components of the forest were assessed in a 1 ha sample plot and four 400m2 quadrats. The values of the biodiversity indexes (as defined by Shannon and Weaver, Krebs and Meyer), species richness and evenness, the distribution of the different stand development stages and the proportion of dead wood lead to the conclusion that Pljesevica forest presents a set of structural and dynamic characteristics close to the ones typical for virgin forests in Europe, so in order to maintain its status as such, in the meantime it should undergo a protection management programme.
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%.
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%.
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%.
Određivanje prostornog rasporeda sekundarnih šumskih prometnica predstavlja jedan od osnovnih parametara za određivanje optimalne otvorenosti odjela. Za što kvalitetniju izradu studije otvorenosti ...odjela, primijenjeni su moderni instrumenti, softveri i metode u postupku prikupljanja i analize terenskih i sastojinskih čimbenika, te analize postojeće sekundarne mreže. Ove analize su neophodne za pravilno i opravdano projektiranje novih i optimizaciju postojećih elemenata sekundarne prometne mreže u odjelu. Također, obrađena je problematika s tehničkog, ekološkog i ekonomskog gledišta privlačenja te funkcija sekundarne mreže u istom.Značajan segment rada predstavlja analiza kvantitativnih i kvalitativnih obilježja postojeće mreže u odjelu 94/1 G.J. "Šiša-Palež" Š.P.P. "Ključko". Analiza kvantitativnih obilježja rađena je na temelju prethodno snimljenih elemenata sekundarne mreže pomoću GPS uređaja i njihove obrade u GIS-u. Na ovaj se način planirala sekundarna mreža, te uz pomoć GIS alata i analiza došlo se do podataka na temelju kojih su izračunati parametri otvorenosti i kreirale se odgovarajuće tematske karte. Slijedom toga planirao se uzorak za procjenu kvalitativnih obilježja postojećih elemenata sekundarne mreže. Ove informacije imale su veliko značenje u fazi optimizacije postojeće mreže prometnica te izrade varijante I.
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