Šumske ceste kao trajni građevinski objekti zahtijevaju ispunjene minimalno propisane kvalitete i standarda tijekom izgradnje. Prema dostupnim podacima prosječni troškovi gradnje šumskih cesta u F BiH za 2019. godinu iznosili su 22.282,19 € po dužnom kilometru (Anon 2019a). Ovako niski troškovi gradnje nameću opravdano pitanje kvalitete novoizgrađenih šumskih cesta i potrebno mu je posvetiti odgovarajuću pozornost. Na području F BiH, zbog niza razloga, sve se više grade prilazne ili tzv. tehnološke šumske ceste, koje se zbog činjenice da se radi o vrsti šumskih cesta bez izvedene kolničke konstrukcije mogu koristiti samo po suhom vremenu te zbog toga ne ulaze u obračun klasične otvorenosti šuma. Osim toga, zbog nedostatka odvodnih jaraka i prevelikog uzdužnog nagiba nivelete na ovim cestama mogu nastati nesagledive ekološke posljedice. S obzirom da postojeća otvorenost šuma u F BiH nije na zadovoljavajućoj razini, cilj svih šumarskih poduzeća je njeno povećanje. Kako se gradnjom šumskih cesta bez izvedene kolničke konstrukcije ne utječe na povećanje otvorenosti, količina cesta koju je potrebno izgraditi za dostizanje ciljane klasične otvorenosti ostaje nepromijenjena. Kao rješenje za riješavanje navedene situacije, u praksi se u posljednje vrijeme sve više grade šumske ceste s elementima koji čine kombinaciju sporednih i prilaznih šumskih cesta. U ovom radu je izvršena analiza tehničkih i konstruktivnih elemenata za novoizgrađenu šumsku cestu „Braćinac - Doljanske stijene“ stacionaže 1,72 km. Na osnovi dobivenih rezultata, došlo se do saznanja o elementima koje na ovoj cesti treba unaprijediti kako bi se ista očuvala, odnosno kako bi se omogućilo njeno dugogodišnje korištenje. S tim u vezi evidentirana su odstupanja uzdužnog nagiba nivelete u odnosu na propisane veličine na 41% od ukupne dužine, na 26% od ukupne dužine nagibi škarpi usjeka nisu prilagođeni kategoriji materijala u kojoj su izgrađene, duž cijele šumske ceste nisu izgrađeni odvodni kanali. Navedena odstupanja daju za rezultat propadanje kolničke konstrukcije, s obzirom da su na 24% evidentirana manja, a na 9% veća oštećenja. Imajući u vidu da su mjerenja na terenu urađena samo godinu dana nakon izgradnje šumske ceste, nameće se zaključak da niska kvaliteta gradnje i nepridržavanje tehničkih propisia rezultira ubrzanim propadanje ceste.

The negative influence of timber harvesting on the forest environment is reflected through damage to the residual trees, regeneration, and forest soil. Considering that skidding, a popular extraction method, can cause substantial and severe damage to the remaining stand, the aim of this research was to determine damage to residual trees during skidding by an LKT 81T cable skidder, including oxen bunching. The research was conducted in eastern Bosnia and Herzegovina, in an uneven-aged mixed fir (Abies alba Mill.) and spruce (Picea abies L.) forest with pine (Pinus sylvestris L.) on limestone soils. Tree felling was conducted using a Husqvarna 372 XP chainsaw. Extraction operations caused damage to 6.31% of the residual trees in the stand. The most damage was “removed bark” (65.34%) and occurred on the lower parts of the tree, the butt end (55.11%) and root collar (32.39%). The average size of the damage was 197.08 cm2. A statistically significant correlation was found between the damage position and the diameter at the breast height (p < 0.05) and the damage position and damage size (p < 0.01) by Spearman correlation analysis. The conducted analysis by the chi-squared test showed that there is a statistically significant difference in the proportion of damage for trees with different distances to the nearest skid road (p = 0.0487), but the share of damaged trees did not decrease by increasing the distance from the skid road.

The paper investigates the phenomenon of soil erosion on skid roads/trails. The aim was to discover how and to what extent different longitudinal slopes can influence the occurrence of erosion processes. For this purpose, a total of nine experimental plots were set up at three different sites. The length of the plots was 110 m, and at all localities, the research was carried out on different longitudinal slopes (up to 10%, 10 - 20% and over 20%) over the observed period of approximately two and a half years. The research focused on determining the volume of material removed and the dynamics of the development of erosion processes observed in phases (shifts) between recordings. Forests are the most effective natural factor in protecting land from erosion, and if they are managed on the principles of sustainable management, the so-called "normal" erosion usually occurs. However, as it is necessary to build a relatively dense network of skid roads/trails for different phases of management, it makes them susceptible to more intensive erosion processes. If we take into account that they were built with very low criteria (technical elements) and without the existence of facilities that would ensure the drainage of surface and rainwater, and can be built with a large longitudinal slope, it creates optimal preconditions for the development of intensive erosion process. The conducted research has obtained results that clearly show that erosion processes occur frequently, of varying intensity depending on the factors that prevail for a given locality. The value of the volume of the removed material ranges from 1.278 m3, ie 0.0116 m3/m to 5.313 m3, or 0.0483 m3/m. The obtained minimum value of the volume of the removed material can be related to the strong water permeability of the parent substrate (limestone), which affects the reduction of surface runoff, as well as shallow soils that are formed on it. When it comes to the maximum value of the volume of removed material, which is 5.333 m3 or 0.0483 m3/m, it can be related to the continuous occurrence of surface runoff that causes surface sapping and removal of material from the skid roads/trails. The performed statistical analyzes (through a linear model) indicate different correlations of investigated influencing factors (volume of transported material and length of skid roads/trails on different longitudinal slopes). The obtained correlation values range from r = 0,29 (weak correlation) to r = 0,79 (very strong correlation).

UDK: 630*232:582.475(497.6) It is well known that mechanical damage to trees, caused by felling and removal of timber from the forest, has multiple negative effects on the quality of the stock and the health of the forests as well as the volume increment. In Bosnia and Herzegovina there were no significant analises of volume increment loss due to bark damage of the trees. In this paper, a direct relationship between the significant damage to the bark of the stem and the size of the volume increment of individual trees was determined. Original data recorded during the Second National Forest Inventory in Bosnia and Herzegovina (2006-2009), within the accesible high economical forests was used. These forests cover a total area of 1.329.500 ha. Data on measured trees was taken from every fourth sample plot (one from cluster). 18.546 trees were selected, on which the 10-year increment of brest diameter (DBH) was measured and significant mechanical damage was recorded (LOJO et al., 2008). Of the total number of selected trees, 2.635 or 14.21% were mechanically damaged. The results of the study showed that the volume increment of trees, with significant bark damage of all tree species and thickness, was lower from 4,9% to 19,4% in average, compared to undamaged trees. Based on registered damage the bark of the stem, during second NFI BiH and determined the average losses increment on individual trees, it was estimated how much these losses are on an annual basis in, productive high forests in Bosnia and Herzegovina. The volume increment of mechanically damaged trees is statistically significantly lower compare to the increment of undamaged trees, resulting in a total loss of about 200.000 m3 / year / 1.329.500 ha.

U radu su prikazani rezultati istraživanja učinkovitosti skidera Ecotrac 55V. Istraživanje je provedeno u šumskom odjelu 89, gospodarska jedinica »Igman«, uz primjenu studija rada i vremena. Trajanje radnoga vremena ustanovljeno je »povratnom« metodom snimanja. Ovisnost vremena trajanja radnih operacija o utjecajnim čimbenicima utvrđena je uz primjenu višestruke regresijske analize. Primijenjena je sortimentna metoda izrade drva. Snimljeni su ovi utjecajni čimbenici: stanje traktorskoga puta (podloge), udaljenost privlačenja drva skiderom, udaljenost privitlavanja drva, broj komada u tovaru, obujam tovara i uzdužni nagib traktorskoga puta. Udio operativnoga vremena u ukupnom radnom vremenu iznosi 38,75 %, a udio vremena prekida rada 37,56 %. Norme vremena i učinka izražene su u ovisnosti o udaljenosti privlačenja, dok su za ostale utjecajne čimbenike korištene prosječne vrijednosti. Utvrđena je norma vremena u iznosu od 8,34 min/m3 za udaljenost privlačenja od 100 m, odnosno 17,65 min/m3 za 900 m. Učinak se traktora kreće u intervalu od 57,58 m3/radnom danu za udaljenost privlačenja od 100 m do 27,20 m3/radnom danu za 900 m. Analiza je pokazala da postoji mogućnost povećanja učinkovitosti primjenom bolje organizacije rada i smanjenjem udjela prekida rada u ukupnom radnom vremenu, osobito prekida iz organizacijskih i osobnih razloga (prekida zbog jela i prekida zbog odmora i osobnih potreba radnika).

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.

S obzirom na to da je šumarstvo djelatnost u kojoj su radnici izloženi relativno velikom stepenu opasnosti od nastanka povreda i profesionalnih oboljenja, ova pojava zahtijeva poseban pristup u segmentu zaštite na radu. Učestalost pojavljivanja povreda i profesionalnih oboljenja u šumarstvu dobar su pokazatelj nivoa sigurnosti radnika pri radu. Iz tog razloga se kroz analizu povreda na radu u JP ŠPD „Unskosanske šume” d.o.o. Bosanska Krupa nastojalo steći uvid u stanje sigurnosti na radu. Analiziran je period od 10 godina (2010–2019) i u tom periodu je evidentirano 213 povreda za cijelo preduzeće. Analiza povreda je obavljena po godinama i mjesecima, prema mjestu nastanka, prema radnom mjestu, prema materijalnom izvoru povrede, prema starosnoj dobi radnika, prema povrijeđenom dijelu tijela, itd. Na osnovu broja povreda po zapremini izrađenoga drveta (43/mil.m3), stanje sigurnosti pri radu može se ocijeniti kao zadovoljavajuće. Najzastupljenije su povrede ekstremiteta (64%), zatim, povrede su češće početkom radne sedmice (26,3%). Najčešći uzrok povrede bio je izazvan padom (62%). Analiza broja povreda po godinama u analiziranom periodu pokazuje da se ističu 2018, a naročito 2019. godina, što se može povezati sa trendom povećanja obima poslova u vlastitoj režiji. Takođe, analiza je pokazala da se najviše povreda desi u ljetnim mjesecima. Prema analizi koja se odnosi na invalide rada, ustanovljeno je da većina registrovanih invalida rada u preduzeću spada u invalide druge kategorije. Invalidi rada čine čak 10,36% ukupne radne snage. Za skoro 80% invalida rada kao glavni uzrok invalidnosti navedena je bolest, tj. razne zdravstvene tegobe koje su smanjile njihovu radnu sposobnost. Samo dvojica radnika su invalidi zbog profesionalnog oboljenja, što je veoma ohrabrujući podatak. Bez obzira na značajan tehnološki napredak i razvoj, posao u šumarstvu se još uvijek smatra jednim od najopasnijih zanimanja na svijetu.

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.

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.

Chainsaw is the main tool for work in a phase of wood felling and processing of forest harvesting in BiH. The aim of the research was to determine fuel and lubricant consumption of the chainsaws Husqvarna 365 and Dolmar PS – 7310 in the phase of felling and processing of wood assortments at the area of P.J. Forest Office „Zavidovići“, forest compartment 203. The volumetric method was applied for the measurement of fuel and lubricants consumption, with precise determination of fuel and lubricant quantity in chainsaw tanks. In total 140 trees of the sessile oak were felled (70 trees with chainsaw Husqvarna 365 and 70 trees with chainsaw Dolmar PS – 7310) during the research. The diameter at the breast height of felled trees ranged from 15 to 84 cm, while tree height ranged from 10,3 to 37,2 m. The total volume of processed assortments was 180,11 m3. The average fuel consumption per m3 processed assortments was 0,306 L/m3 for trees felled by chainsaw Husqvarna 365 which is for 0,042 L/m3 larger in comparison to chainsaw Dolmar PS – 7310 with average fuel consumption of 0,264 L/m3. The average lubricant consumption per m3 processed assortments was 0,102 L/m3 for trees felled by chainsaw Husqvarna 365 which is for 0,012 L/m3 larger in comparison to chainsaw Dolmar PS – 7310 with average lubricant consumption of 0,09 L/m3. Considering conducted research it can be assumed that there are differences in fuel and lubricant consumption between this two type of chainsaws for considered working conditions, but differences are not statistically significant.

Production of solid fuels from wooden biomass is defined with appropriate energy chain of supply. The notion of energy chain concept has been defined as the trajectory of energy transformations from the fuel source or energy sources to useful energy form to end users. Supply chain for production solid fuels from wooden biomass is also energy chain with high importance in biomass energy planning. In this paper, base for testing and research is developed mathematical model in previous published paper with preliminary note titled as “Multi-Criteria Optimization Concept for the Selection of Optimal Solid Fuels Supply Chain from Wooden Biomass“ at Croatian Journal of Forest Engineering. Three supply chains have been included in comparison: production of wood chips at the terminal – variant 1, production of pellet – variant 2 and production of wood chips by means of a mobile chipper in a forest – variant 3. The VIKOR methodology is used for total ranking all mentioned chains. Real input data have been used for mathematical calculation correspond to Bosnia and Herzegovina conditions.

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.