Evaluation of Morphometric Terrain Parameters and Their Influence on Determining Optimal Density of Primary Forest Road Network

Planning forest truck roads network involves a lot of factors that directly affect their density and length. Depending on the purpose of the forest truck road network, this number is higher or lower. Our opinion was that these factors should be divided into invariable and variable. Common parameters, regardless of the purpose of the roads, are morphometric parameters because they can limit the length and density of the network of forest truck roads due to their variety of forms. For this reason, this paper deals exclusively with the morphometric characteristics of the terrain and their influence on the density of the network of forest truck roads. The DEM of the terrain was processed with GIS software based on the seven most important influencing factors. By standardizing the criteria, the obtained maps were reclassified, and then each of the seven selected parameters was weighted with the coefficients obtained by the AHP method. In this way, a map of the suitability of the terrain for the construction and addition to the existing network of forest truck roads was obtained. The terrain is divided into 4 categories of suitability. Zero lines were drawn with GIS tools for road design. During the creation of the optimal road network, it was tested with absolute and relative openness. As a final result, each of 26 Forest Economic Areas (FEA) was assigned to one of 4 categories of terrain suitability for the construction and density of the forest truck road network. For each category of terrain convenience, the optimal absolute and relative openness is shown. Based on this work, we suggest that the use of morphometric parameters should be considered as the first step of forest road planning in other regions

Analiza isplativosti harvestera John Deere 1470D Eco III u nasadima topola (Populus × Canadensis) – studija slučaja

In the last few years, harvesters have been increasingly used in stands of deciduous tree species. The use of harvesters in Serbia began in 2008 with John Deere 1470D Eco III and it was used for felling trees and production of wood assortments in poplar plantations in the lowland area. The aim of this paper is to determine maximum profit by engaging a harvester in the given conditions, as well as to determine the total costs of the asset. Harvester achieved a total of 18,392 machine hours (MH), with an average of 1,415 hours per year. The average fuel consumption during the entire period was 16.3 l/h, or 0.76 l/m3. The highest cost of spare parts was in the 6th year (around 66,000 euros) and in the 12th year (around 82,000 euros). The total cost of spare parts and services was 656,878 euros. Based on the planning that the number of work days per year is 200, an amortization period of 7 years is obtained (the point of intersection of current and average profit growth). Results of this research indicate that harvesters older than 7 years should be replaced with new machines, due to high maintenance costs. However, these are only initial researches, which will be continued with data on several harvesters that have been procured in the meantime.Posljednjih nekoliko godina harvesteri se sve više koriste u sastojinama listopadnih vrsta drveća. Korištenje harvestera u Srbiji počelo je 2008. godine sa John Deere 1470D Eco III i služio je za sječu stabala i proizvodnju drvnih sortimenata u nasadima topola u nizinskom području. Cilj ovoga rada je odrediti maksimalnu dobit angažiranjem harvestera u zadanim uvjetima, kao i utvrditi ukupne troškove sredstava. Harvester je postigao ukupno 18,392 strojna sata (MH), s prosjekom od 1,415 sati godišnje. Prosječna potrošnja goriva tijekom cijelog razdoblja iznosila je 16.3 l/h, odnosno 0.76 l/m3. Najveći trošak rezervnih dijelova bio je u 6. godini (oko 66,000 eura) i u 12. godini (oko 82,000 eura). Ukupni troškovi rezervnih dijelova i usluga bili su 656,878 eura. Na temelju planiranja da je broj radnih dana u godini 200, dobiva se razdoblje amortizacije od 7 godina (točka presjeka tekućeg i prosječnog rasta dobiti). Ova informacija nam govori da bismo nakon 7. godine trebali harvester prodati i kupiti novi. No, ovo su samo početna istraživanja, koja će se nastaviti s podacima o nekoliko harvestera, koji su u međuvremenu nabavljeni

Ozljede pri šumskom radu u Šumskome gospodarstvu „Sremska Mitrovica“ u Srbiji

In most developed countries forestry is among the occupations with the highest rate of occupational injuries. The aim of this study was to determine the frequency and main causes of occupational injuries in Serbian forestry. The data were collected in the area managed by the Forest estate (FE) „Sremska Mitrovica“ for the period from 1st January 2008 to 31st December 2012. The analyses involved workers engaged in different forest work operations (logger, manual loader, silvicultural worker and driver). The data analysis showed that light injuries account for 95% of all occupational injuries, while severe occupational injuries account for 5% of them. In the analyzed period there were no fatal injuries. The percentage of injuries in the total number of workers is 12%. The most commonly injured workers were loggers (68%). According to the analysis, every fourth logger was injured, and the largest number of them were injured once (99 workers). Twenty-six of them were injured twice during the same period and 9 three or more times. The average logger age was 38.8, and their average length of service was 16 years. The largest number of logger injuries occurred in March and May, on Mondays (almost 1/3 of injuries) in the period from 10 to 11 AM, and the most frequently injured body parts were the legs (38%) and arms (35%). The most common cause of injury is the blow of a branch (35%).Šumarstvo je jedna od gospodarskih grana gdje je stopa ozljeda na radu među najvećima. Uprkos tomu što se poslovi u šumarstvu uglavnom karakteriziraju sezonalnošću, a ne stalnom zaposlenošću radnika, šumsko gospodarstvo „Sremska Mitrovica“ gdje su provedena istraživanja ima drukčiju praksu. Cjelokupna sječa i izrada na području ovoga gospodarstva obavlјa se ulaganjem vlastitih sredstava i vlastite radne snage. Ovo gospodarstvo karakterizira ravničarski teren s prosječnim nadmorskim visinama ispod 100 m, gdje glavne vrste drveća čine euroamerička topola, lužnjak i jasen. Godišnji etat šumskog gospodarstva iznosi oko 200 000.00 m3. U ovome radu prikazani su rezultati istraživanja broja i uzroka ozljeda na radu, za razdoblje od 5 godina (2008-2012. godine). Analizirane su samo ozljede proizvodnih šumskih radnika (sjekači, radnici koji rade na ručnom utovaru, vozači i radnici koji rade na poslovima uzgajanja šuma). Svaka ozljeda na radu evidentirana je odmah nakon što se dogodila. Klasifikacija ozljeda obavljena je na temelju Međunarodne klasifikacije bolesti (International Classification of Diseases and Related Health Problems), a korišten je šifrarnik bolesti iz odjeljka „vanjski uzroci obolijevanja i umiranja (V01-Y98)“ (external causes of morbidity and mortality) (V01-Y98)). Nakon svake evidentirane ozljede na radu, medicina rada je slala Izveštaj o liječničkom pregledu ozlijeđenog radnika Republičkoj inspekciji rada, Ministarstvu unutrašnjih poslova i ­referentu zaštite na radu u radnoj jedinici gdje je radnik bio zaposlen. Iz Izveštaja o liječničkom pregledu ­zaposlenog podaci su unošeni u posebnu evidenciju. Ocjenu težine ozljede davao je liječnik koji je prvi ­pregledao zaposlenog. Radnicima koji su radili kao sjekači, šumsko gospodarstvo osiguralo je tečaj koji je trajao mjesec dana (teorijska nastava) i dva mjeseca praktične obuke, gdje su sjekači obavili sječu i obaranje uz pomoć iskusnijeg kolege (mentora).Ukupan broj radnika koji je na godišnjoj razini bio zaposlen na poslovima korištenja šuma kretao se od 302 (2010. godine) do 323 (2008. godine) (Tablica 1). Najveći broj radnika bio je zaposlen na poslovima uzgajanja šuma. Na temelju analize broja ozljeda na radu u razdoblju od 2000-2012. godine utvrđeno je da je najveći broj ozljeda na radu zabilježen kod radnika koji su radili kao sjekači (Slika 2). Ukupan broj ozljeda koji je evidentiran u razdoblju 2008-2012. godine je bio 181, gdje su 172 ozljede evidentirane kao lake, dok je 9 ozljeda kategorizirano kao teška tjelesna ozljeda. Od ukupnog broja ozlijeđenih radnika, najveći postotak čine radnici koji su obavljali posao sjekača (68 %), zatim posao radnika koji su radili na poslovima uzgajanja šuma (20 %), vozača traktora (8 %), radnici koji rade na ručnom utovaru (3 %) i vozača kamiona (1 %) (slika 3). Postotak ozlijeđenih sjekača u odnosu na ukupan broj iznosi 25 %. Najčeće su se povređivali sjekači starostne dobi između 30 i 40 godina (Slika 4), odnosno oni radnici koji su imali između 15 i 20 godina radnog staža (Slika 5). Najveći broj ozljeda sjekača dogodio se u ožujku i svibnju. Promatrajaći dane u tjednu, najveći broj ozljeda dogodio se ponedjeljkom (skoro 1/3 povreda). Najveći broj ozljeda dogodio se u razdoblju od 10-11 sati prije podne (Slika 8). Najčešće povređivan dio tijela su noge i ruke (Slika 9). Najčešći uzrok ozljede je udarac grane (35 %), zatim sljede ozljede uzrokovane lancem motorne pile (21 %) (Slika 10). Ono što su ­autori ovoga članka zapazili analizirajući podatke, je činjenica da evidencije o povredama radnika postoje, ali da nisu bile uniformne ni po godinama ni po radnim jedinicama, i često su nedostajali detaljni podaci o ­povredi.Tako je odlučeno da se u idućem razdoblju u dogovoru s nadležnima iz JP kreiraju novi obrasci koje treba popunjavati sukladno preporukama, koji će također biti dati kao prateći materijal

OŠTEĆENJA NA PREOSTALIM STABLIMA I POMLATKU TIJEKOM SJEČE I PRIVLAČENJA DRVA U MJEŠOVITIM I ČISTIM BUKOVIM SASTOJINAMA

This paper presents an analysis of damage to residual trees and the regeneration that occurs during harvesting using the half tree length method and timber extraction in winter operating conditions in a pure beech stand and a mixed stand of beech fir and spruce in the territory of the Srpska Republic. In this study, types of damage were investigated, as well as the size of wounds. Felling and processing of wood assortments were performed with a chainsaw and timber extraction on earth and by skid trail to a roadside landing on a truck road was performed with a tractor Timberjack 240C. The number of injuries that occurred during the felling and transport of trees in the mixed stand was on average 2.69 wounds per felled tree, whereas in the pure stand the average number of wounds per felled tree was 2.27. During the felling of trees in both sample plots, the largest number of injuries was to the crowns of neighbouring trees, which was followed by damage to the butt end, whereas the lowest number of injuries was incurred to the root collar. During the timber winching, the most common damage was to the root collar, whereas during timber skidding the most common type of damage was to the butt end. Damage to the regeneration was evident in both sample plots in the form of breakages of plants and their branches, as well as uprooting of whole plants. Damage to the butt end and root collar that occurred at the felling stage was in the form of bark peeling and other superficial wounds whose most common sizes were larger than 200 cm2. The average area of injuries caused during the transport phase ranged from 50 to 200 cm2.Tijekom mehanizirane sječe i privlačenja drveta nastaju oštećenja na preostalim stablima, podmlatku i zemljištu. Vrsta i veličina oštećenja koje se javljaju pri sječi, izradi i privlačenju drvnih sortimenata ovisi od broja stabala u sastojini, gustoće pomlatka, intenziteta sječe, promjera stabla, veličine krošnje, smjera obaranja stabala, nagiba terena, metoda izrade drvnih sortimenata, uvježbanosti rukovatelja, ali i od gustoće primarne i sekundarne mreže puteva. Cilj ovoga rada je utvrđivanje broja i veličine oštećenja na preostalim stablima i podmlatku u čistoj sastojini bukve i mješovitoj sastojini bukve, jele i smreke, kada se primjenjuje poludeblovna metoda. Uz to, cilj rada je i rangiranje oštećenja prema učestalosti nastanka tijekom sječe stabala i transporta drvnih sortimenata.Istraživanja su vršena tijekom 2009. godine u čistoj sastojini bukve i mješovitoj sastojini bukve, jele i smreke na području općine Čajniče, Republika Srpska (Slika 1), na dvije pokusne površine. Sječa i izrada sortimenata izvršena je motornom pilom. Primijenjena je poludeblovna metoda izrade drvnih sortimenata i grupni način rada. Privlačenje dijelova debala i debljih grana obavljeno je traktorom Timberjack 240C po zemlji do traktorske vlake i po vlaci do kamionskog puta gdje se nalazilo privremeno stovarište.S obzirom na broj oštećenja na preostalim stablima u sastojini, uočeno je da su oštećenja na krošnjama susjednih stabala na obje pokusne površine najučestaliji način oštećenja (Slika 2). U mješovitim sastojinama evidentirano je 169 oštećenja (0,75 po jednom stablu), a u čistim 77 oštećenja (0,77 po jednom stablu). Najmanje oštećenja tijekom sječe stabala javilo se na žilištu stabala. Na PP 1 ovaj način oštećenja uočen je na samo tri stabla (0,01 oštećenje po stablu), a na PP 2 na 12 stabala (0,12 oštećenja po stablu).Tijekom privlačenja drvnih sortimenata do vlake, najučestalija oštećenja bila su na žilištu (Slika 2). U mješovitoj sastojini evidentirano je 48 stabala koja su imala ovo oštećenje (0,32 oštećenja po zahvatu vitla), a u čistoj sastojini 27 stabala (0,24 oštećenja po zahvatu vitla). Oštećenja na deblu i krošnji nisu zabilježena, dok su oštećenja na pomlatku vrlo izražena. Pri privlačenju sortimenata pozicioniranih paralelno s izohipsama najčešće dolazi do okretanja sortimenata oko svoje osi, što uglavnom uzrokuju ozljede na preostalim stablima i podmlatku (Slika 5).Tijekom vuče drvnih sortimenata po vlaci do stovarišta na kamionskom putu, najčešći oblik oštećenja bio je na deblima. Ukupan broj oštećenja na deblima u mješovitoj sastojini iznosi 116, odnosno, 12 % od ukupnog broja stabala koja su se nalazila uz vlaku bilo je oštećeno na ovaj način. Oštećenja na podmlatku evidentna su kako pri sječi, tako i u tijeku skupljanja i privlačenja (Slika 2). U svakom slučaju, zbog veće gustine pomlatka u mješovitoj sastojini i broj oštećenja po srušenom stablu, odnosno po zahvatu vitla, znatno je veći nego u čistoj sastojini.Pri sječi stabala u mješovitoj i čistoj sastojini najviše su zastupljena oštećenja čija je površina veća od 200 cm˛, a pri skupljanju i privlačenju drvnih sortimenata oštećenja veličine od 50 do 200 cm

Percutaneous Computed Tomography-Guided Oxygen-Ozone (O₂O₃) Injection Therapy in Patients with Lower Back Pain—An Interventional Two-Year Follow-Up Study of 321 Patients

Objectives: To assess the effect of oxygen-ozone therapy guided by percutaneous Computed Tomography (CT) compared to corticosteroids in individuals experiencing lower back pain (LBP) not attributed to underlying bone-related issues. Methods: A total of 321 patients (192 males and 129 females, mean age: 51.5 ± 15.1 years) with LBP were assigned to three treatment groups: group A) oxygen-ozone only, group B) corticosteroids only, group C) oxygen-ozone and corticosteroids. Treatment was administered via CT-guided injections to the intervertebral disc (i.e., intradiscal location). Clinical improvement of pain and functionality was assessed via self-reported pain scales and magnetic resonance (MR) and CT imaging. Results: At all follow-up times, the mean score of the numeric rating scale and the total global pain scale (GPS) of study groups receiving oxygen-ozone (groups A and C) were statistically significantly lower than the study group receiving corticosteroids only (group B), with p &lt; 0.001. There was a statistically significant difference between groups A and C at 30 days for the numeric rating scale. Conclusions: The percutaneous application of oxygen-ozone in patients with LBP due to degeneration of the lumbosacral spine showed long-lasting significant pain reduction of up to two years post-treatment when compared to corticosteroids alone. Combination therapy of oxygen-ozone and corticosteroids can be useful as corticosteroids showed statistically significant improvement in LBP earlier than the oxygen-ozone-only treatment.</p

Efficiency of different systems of work within tree felling and making of wood assortments : doctoral dissertation

Seča stabala i izrada drvnih sortimenata u Srbiji se u preko 90% slučajeva obavlja motornim testerama. U literaturi se navodi da je posao radnika koji rukuje motornom testerom jedan od najtežih, ali i najopasnijih. Osnovni cilј ovog istraživanja je bila ocena efikasnosti i izbor odgovarajuće organizacione forme rada u seči stabala i izradi drvnih sortimenata u različitim uslovima rada, istovremeno uvažavajući više faktora. Ovo istraživanje obavljeno je na 7 oglednih površina (5 u ravničarskom i 2 u brdsko-planinskom predelu), gde su seča stabala i izrada drvnih sortimenata obavljene motornim testerama Stihl i Husqvarna, koje su se razlikovale po snazi. Istraživane su tri različite forme rada (1M (radnik koji rukuje motornom testerom) +0R (pomoćni radnik), 1M+1R i 2M+0R) u sastojinama različitih vrsta drveća i različitim vrstama seče (čista seča u zasadima topole, proredna seča u sastojini hrasta i prebirna seča u sastojini bukve i jele). Utvrđeno je da postoje statistički značajne razlike u ostvarivanju učinaka između organizacionih formi rada, ali i između vrste drveća. Potrošnja goriva najviše zavisi od prečnika stabla na prsnoj visini, zatim od vrste drveća, a tek onda od snage motorne testere i organizacione forme rada. Utvrđeno je da je se najmanja potrošnja goriva i maziva, ali i potrošnja energije kao i emisija štetnih gasova ostvaruje kombinacijom dve motorne testere u sastojini bukve (jedne veće i jedne manje snage), u organizacionoj formi rada 2M+0R. Utvrđeno je da na štete na preostalim stablima u seči stabla izradi drvnih sortimenata najveći uticaj imaju prečnik posečenog stabla, zatim nagib terena i sklop sastojine, dok na štete na podmlatku najveći uticaj ima veština rukovaoca. Ukupno opterećenje dvojice radnika koji rukuju jednom većom i jednom manjom testerom u proseku je za 11% manje u odnosu na grupu radnika koji rukuju dvema testerama veće snage, pa je i sa ergonmskog aspekta povoljnija varijanta kombinacije veće i manje testere (kao i kod potrošnje goriva i maziva).Felling and processing of wood assortments in Serbia is performed with chainsaws in over 90% of cases. It is stated in the literature that the job of a chainsaw operator is one of the most difficult but also the most dangerous ones. The main goal of this research was to evaluate the efficiency and choose the organizational form of work in tree felling and wood assortments processing under different operating conditions, while taking into account several factors. This research was carried out in 7 sample plots (5 in a lowland area and 2 in a hilly-mountainous area), where the felling of trees and wood assortments processing were performed with Stihl and Husqvarna chainsaws, of different powers. Three different forms of work (1 worker with chainsaw (C), without assistant (A) – 1C+0A, 1C+1A and 2C+0A) were investigated in stands of different tree species and different types of felling (clear felling in poplar plantations, thinning in oak stands and selection cutting in a beech and fir stand). It was established that there are statistically significant differences in the achievement of results between the analyzed organizational forms of work, but also among the tree species. Performance increases with an increase in diameter class in all organizational forms of work. Fuel consumption mostly depends on the diameter at breast height, after that on the tree species, and only then on the power of the chainsaw and the organizational form of work. It was found that the lowest fuel and oil consumption, as well as energy consumption and emission of harmful gases, are achieved when two chainsaws in beech forest (one of higher and one of lower power) are combined, in the organizational form of work 2C+0A. It was established that the diameter of the felled tree, the slope of the terrain and the composition of the stand have the highest impact on the damage to the remaining trees in felling and wood assortment processing, while damage to the regeneration is most influenced by the operator's skill. The load of two workers who handle one larger and one smaller saw is on average by 11% lower compared to the group of workers who handle two saws of higher power, so from an ergonomic point of view (as well as in terms of fuel consumption and lubricants), the combination of a larger and a smaller saw is more favourable

Work efficiency in the operations of juvenile thinning of mixed stands of pedunculate oak with hornbeam, ash and other hard broadleaves with the Stihl MS 260 chainsaw

This paper presents the results of research of efficacy of the lightweight low power chainsaw Stihl MS 260 in the operations of juvenile thinning in preserved even-aged mixed stands of pedunculate oak with hornbeam, ash and other hard hardwoods. The investigations were carried out in the territory of FE “Sremska Mitrovica” in three sample plots of different ages. It is the first research of this kind based on the choice of optimal technological solution for the cleaning cuts of oak stands. Technology of work is based on cutting unwanted species at a certain height in order to favor pedunculate oak as the main species. In sample plot 1 the cutting through of undesirable species was carried out in one place and then third parties carried out their processing and transportation. In sample plots 2 and 3 workers cut the unwanted species in several places and stacked the timber on the ground so as not to interfere with the growth of pedunculate oak which does not tolerate shading. In this study, we applied time and work study. Group system of work was recorded. The group typically consisted of 4 workers and a foreman. Fuel consumption was recorded by the method of tank refuelling. The research results show that operating conditions have a significant impact on the effects of work with a chainsaw, as well as on the consumption of fuel and lubricants. The differences are mainly caused by different structures of cut timber

EFEKTI RADA NA POSLOVIMA SEČE I IZRADE DRVNIH SORTIMENATA U PROREDNIM SEČAMA BUKVE

U radu su prikazani rezultati istraživanja efikasnosti primeneorganizacione forme rada 2MR pri s

Impact of Chainsaw Power on Fuel and Oil Consumption

This research was carried out in a selection stand of beech and fir, where logging was performed with chainsaws of different powers. Two chainsaws of 3.9 kW were used for work on one area, while on the other one the applied tools were a combination of a smaller and a larger saw (2.5 kW and 3.9 kW). After logging, the consumption of energy products (fuel (gasoline and motor oil mix ratio 50:1) and chainsaw oil) was measured for each individual chainsaw by the method of refueling. It was found that the power of the chainsaw, i.e., the combination of chainsaws of different powers, significantly influences the consumption of energy products in a beech&ndash;fir mixed stand. By using a combination of one larger and one smaller chainsaw instead of two larger chainsaws, savings of about 26% for fuel and 24% for oil were achieved. The prediction analysis found that by using two chainsaws (of lower and higher power) instead of two higher power chainsaws (currently common mode of work) in beech stands for an estimated volume of about 1 million m3 year&minus;1, the savings could be about 54,000 L of fuel and about 19,000 L of oil. In monetary value, this is a saving of about EUR 120,000 year&minus;1, i.e., of about 2,500,000 MJ year&minus;1 of energy