Background and Purpose: Logging is an example of the strongest human influence on forest environment because it causes damages to the forest soil and residual trees. The damages that occur during ...logging are more frequent in the skidding phase compared to the felling and processing phase.
Material and Methods: The research was conducted in mixed stands of fir and spruce in the area of eastern Bosnia and Herzegovina. Felling was conducted by chainsaw and extraction by animals, i.e. by two oxen. The following data were collected: tree species, diameter at breast height, pre-bunching zone (0-30 m or 30-60 m), presence of damages, presence of old damages, number of damages, type of damage, damage position and the size of damage.
Results: Damages were recorded on 3.32% of residual trees. The average number of damages per damaged tree was 1.08. The same percentage share of damages was recorded on butt end and root collar (38.46%), while damages on root have a share of 23.08%. Stem damages were not recorded. The most common type of damage was debarked tree (61.54%), then squashed bark (23.08%) and debarked and damaged tree (15.38%). It was recorded that the size of damages varied between 60 and 570 cm2. The average size of damage was 222.54 cm2. Statistical analysis using χ2 test showed significant difference in the proportion of damaged trees among different pre-bunching methods, and did not show significant difference in the proportion of damaged trees between different pre-bunching zones.
Conclusions: It can be assumed that oxen logging causes insignificant damages to residual trees. The results of research will be used as a basis for future studies of residual trees’ damaging during wood skidding.
Relative forest accessibility percent of accessible forest area by forest roads in comparison with total forest area is the most important indicator of the quality of primary forest accessibility. ...The accessible forest area by forest roads is determined by the bounded area around forest roads. Today, in the area with steep and variable slopes of terrain, a double targeted geometrical extraction distance of timber is used for the width of the bounded area around forest roads, and the forest road spacing is used in the area with a mild and uniform slope of the terrain. Both parameters depend on the targeted density of forest roads. Modern information technologies (IT) like geographical information systems (GIS) enable the quality spatial and statistical analysis of different kinds of data whose result is not accessible forest areas by current primary forest traffic infrastructure only, but also an insight into the spatial distribution of insufficient accessible areas into the forest area. The spatial distribution of these areas is significant for spatial distribution of the new routes of forest roads. The research is done in the area of Forest Management Unit (FMU) Prosara, for which the spatial analysis of a digital terrain model (DTM) determined the mostly hilly relief area. The average relative forest accessibility, based on double targeted geometrical extraction distance of timber, is 35% for the actual network of forest roads, and targeted forest road spacing is 60% for the upgraded network of forest roads.
Rad obrađuje problematiku otvorenosti šuma mrežom primarne šumske prometne infrastrukture te dinamiku građenja, održavanja i rekonstrukcije šumskih cesta u Federaciji BiH od 2005. do 2020. godine. ...Otvorenost šuma u Federaciji BiH još je značajno ispod potrebne minimalne (15 m/ha za brdsko-planinska područja) za racionalno gospodarenje šumskim resursima. Građenje je novih šumskih cesta imperativ za šumarske tvrtke, međutim dinamika izgradnje novih cesta daleko je ispod potrebne razine. Također, rekonstrukcija postojećih šumskih cesta koje su većinom građene 70-ih i 80-ih godina prošloga stoljeća, a čija nosivost nije usklađena sa zahtjevima suvremenih kamionskih skupova, gotovo pa u potpunosti izostaje. Jedan od osnovnih problema za provođenje predmetne analize jest prikaz podataka šumarskih poduzeća u Federaciji BiH, koja rekonstrukciju, održavanje i redovitu sanaciju daju kao jedan podatak, zbog čega realne pokazatelje stvarno izvršenih radova za pojedinačne vrste radova nije moguće na pravi način opisati. Uz kvantitativne podatke koji su dani u radu, također su iskazani i financijski pokazatelji planiranih i realiziranih radova.
The need for the construction of new roads, as well as the maintenance and reconstruction of existing roads in the Federation of Bosnia and Herzegovina, is constantly present. The paper analyzes the period from 2005 to 2020, primarily on the basis of regular annual information on forest management in the Federation of Bosnia and Herzegovina, and from survey questionnaires that were conducted in forest enterprises for the preparation of the Forest Transport Infrastructure Development Study (2011) and the Forest Transport Infrastructure Development Master Plan (2020). Activities related to forest truck roads in the forestry of the Federation of Bosnia and Herzegovina have unfortunately shown a delayed trend for many years. The completion of construction works of new roads, as well as regular, periodic maintenance and reconstruction over a period of years, has mostly been below the plan, which specifically refers to the construction of new roads. Based on the analyzed data, a significant difference is noticeable between the planned and built forest truck roads in the analyzed period, where a total of 1213.9 km were planned for construction, while only 592.9 km or 48.84 % of the planned roads were completed. Also, when it comes to invested financial resources, a significantly smaller amount was spent than planned. The planned funds amounted to 41.85 million euro, and 14.75 million euro or 35.25 % of the planned amount was spent. The average investment was 24,879 euro/km. The lowest average costs were in 2014, amounting to 8029.5 euro/km, and the highest in 2009, amounting to 42,297.2 euro/km. There are significant differences when it comes to the openness of forests in FB&H based on data collected in different periods and based on different sources. According to Sokolović and Bajrić (2011), the openness is 10.8 m/ha, according to the data of the Master Plan for the Development of Forest Transport Infrastructure (2020), the openness is 7.83 m/ha, while according to the latest available data from the Information on forest management for the year 2020 and plans for the year 2021, the openness of the forests is 11.3 m/ha. The different results lie primarily in the fact that there is no single criterion for calculating the openness of forests in the Federation of Bosnia and Herzegovina. The openness of all forests in FB&H is not uniform, with the highest average in high forests and according to data from the Information on forest management for 2020 and plans for 2021, the same amount is 16.0 m/ha, in forest plantations it is 9.6 m/ha and in coppice forests 11.2 m/ha. When it comes to the funds invested in regular annual and periodic maintenance, as well as the reconstruction of forest truck roads, they are not shown in the correct way in the forestry operation (all works are shown as a single cost), so it is not possible to give a high-quality analysis of these costs.
Šuma ima važnu ulogu u regulisanju vodnog režima, odnosno prevenciji pojave poplava i bujičnih tokova, što zavisi od vrste drveća koje sačinjavaju sastojinu, stepena sklopa, starosti i strukture ...sastojine. U ovom radu istraživan je uticaj strukturne izgrađenosti sastojine na vodni režim na primjeru šumske kulture bijelog bora (Pinus sylvestris L.) na krečnjacima u jugozapadnoj Bosni i Hercegovini. U šumskoj kulturi bijelog bora postavljena je eksperimentalna ploha 50x50 metara na kojoj je izvršen potpuni premjer svih taksacijskih elemenata. Pored toga u različitim uvjetima stepena sklopa postavljeni su kišomjeri pomoću kojih je utvrđivana količina oborina koja dospije do površine šumskog tla. Kišomjeri su postavljeni i na otvorenoj površini u neposrednoj blizini šumske kulture. Istraživanja su pokazala da se sa povećanjem broja stabala na jedinici površine i veće sklopljenosti sastojine povećava zadržavanje oborinske vode u krošnjama stabala i do 30%. U sastojini bijelog bora je utvrđeno 720 stabala po hektaru dok bi za optimalnu intercepciju taj broj trebao biti oko 1.400. Međutim, povećanje broja stabala unutar sastojine se može negativno odraziti na stabilnost sastojine. Kod većeg broja stabala unutar sastojine konkurencija je veća, stabla se suše, vitkost stabala je veća i dolazi do preloma ili izvala stabala. Četrdestogodišnja sastojina bijelog bora je na površini tla formirala šumsku stelju koja ima preko 4 puta veću apsolutnu suhu masu od mase suhe materije pokrova na otvorenoj površini. Istraživanja su pokazala da u skopljenoj sastojini bijelog bora na tlo dospije manja količina oborinske vode, ali da šumska tla imaju bolju sposobnost infiltracije, zadržavanja i ravnomjernog rasporeda vode kroz duži vremenski period. Uzgojnim zahvatima u sastojini može se i sa manjim brojem stabala na jedinici površine postići isti efekat intercepcije ukoliko se potiče bolji razvoj krošnji stabala.
Bosna i Hercegovina ima pretežno brdsko-planinsku konfiguraciju terena, bogata je razvijenom hidrografskom mrežom. Pri projektiranju i izgradnji mreža šumskih cesta učestala je pojava presijecanja ...stalnih ili povremenih vodotoka pa je zato prijeko potrebno planirati i graditi vodopropusne objekte.Najrizičnija su mjesta, kada je u pitanju negativan utjecaj vodotoka na erozijske procese, upravo točke presijecanja šumske ceste rijekama i brdsko-planinskim vodotocima. Da bi se smanjio postotak neupotrebljivosti primarne mreže šumske transportne infrastrukture, treba pristupiti kvalitetnim rješenjima odvodnje površinskih voda i izgradnji prelazaka preko postojećih planinskih vodotoka. Vodna je erozija jedna od mogućih pojava, koja može nastati na kolničkoj konstrukciji, ako na odgovarajući način nije riješeno pitanje odvodnje površinskih i oborinskih voda.Procjena erozijskih procesa prilikom provođenja istraživanja utjecaja hidrografske mreže na primarnu mrežu šumske transportne infrastrukture obavlja se na osnovi terenskoga snimanja stanja vodopropusnih objekata i kolničke konstrukcije u njezinoj neposrednoj blizini.Prilikom istraživanja nisu analizirani tehnički elementi šumskih cesta (osim erodiranosti kolničke konstrukcije), aktivnosti su usmjerene na vodopropusne objekte, odnosno njihovo stanje i eventualni utjecaj na erodiranje kolničke konstrukcije. Istraživanja su provedena u GJ »Neretvica« u okviru ŠPP »Konjičko«.Analizirano je ukupno 129 različitih vodopropusnih objekata, od kojih su 16 mostova, 73 cijevna betonska propusta i 40 drugih tipova objekata. U okviru provedene analize vodopropusnih objekata obrađena je oštećenost i funkcionalnost vodopropusnih objekata te erodiranost kolničke konstrukcije u njezinoj neposrednoj blizini.
Water permeable structures on strip roads play a very important role in regulating the flow of surface water and rainwater. Although the
forestry operative of B&H does not use patterns that can be used to
correctly determine the dimensions of water-permeable structures, most often the selection of the dimensions of the structure that can ensure the smooth flow of water is done experientially.
Previous analyses show that investments in forest road infrastructure are insufficient (Sokolović and Bajrić 2011, 2013) and that this is the most common reason for the poor condition of forest road infrastructure. Erosion is a common occurrence on all unpaved roads, especially in heavy rain events and on steep slopes (Wang et al. 2021). Poor technical solutions, along with irregular maintenance of water-permeable structures, are a common cause of intensification of erosive processes and destruction of the road structure.
In the present study, a total of 129 water-permeable structures of various types were analyzed, of which 16 bridges, 73 concrete pipe culverts, and 40 ‘other’ types (improvised solutions of water-permeable structures, most often made of stone slabs). Bridges have the most efficient functionality, which allows water to flow freely through the flow profile. Also, concrete culverts of larger dimensions (Ø 80 and 100
cm) have better functionality than culverts of smaller dimensions (Ø 40
and 60 cm). Namely, in the case of specific small culverts, frequent partial blockages were observed, the maintenance of which was difficult due to the small dimensions of the culvert.
The worst functionality was observed with ‘other types’ of water-permeable structures, where collapses often occur, and as a result, they cannot be cleaned and have to be replaced instead. Of the total number of ‘other types’ of structures, 50% have difficult or disabled functionality, with 20% of the total number having disabled functionality. It is obvious that the choice of the type of water-permeable structures, as well as their dimensions, play a very important role when it comes to their future functionality.
Also, field research has determined the direct correlation between the functionality of water-permeable structures and the occurrence of erosive processes on the pavement structure in the immediate vicinity. That is, in the case of structures with impaired or disabled functionality, the water partially or completely overflows over
the pavement structure, whereby the surface rubs off the pavement and causes its erosion.
Bosna i Hercegovina ima primarno brdsko-planinski karakter, što uz odgovarajuće geološke prilike pogoduje nastanku brojnih vodenih tokova. Česta je situacija da se u okviru jednog šumskog odjeljenja ...nalazi po nekoliko potoka koje, radi potreba gospodarenjem šumama, presijeca primarna ili sekundarna mreža šumske transportne infrastrukture. Mrežu šumske transportne infrastrukture nije moguće položiti tako da se ista ne ukršta sa brdsko-planinskim vodotocima. Pozicije ukrštanja mogu biti jako osjetljiva mjesta, posebno ukoliko im se ne posveti odgovarajuća pažnja, tačnije, ukoliko se ne nađu tehnička rješenja koja će minimizirati mogućnost negativnog uticaja. Nerijetko se u šumarskoj operativi dešava da usljed loših tehničkih rješenja ukrštanja vodenih tokova i mreže infrastrukture dođe do intenziviranja erozionih procesa izazvanih negativnim djelovanjem vode. Također, i sama infrastruktura može negativno djelovati na prirodni tok, te kao posljedicu lošeg rješenja trase preusmjeriti isti traktorskim putem ili traktorskom vlakom. Sam način izgradnje traktorskih puteva/vlaka, pri čemu se izvode samo zemljani radovi bez izgradnje objekata za podužnu i poprečnu odvodnju površinskih i oborinskih voda, stvara optimalne preduslove za razvijanje erozionih procesa različitog intenziteta. Mjesta ukrštanja vodenih tokova i traktorskih puteva ili vlaka su posebno osjetljiva na erozione procese, što je, između ostalog, dokazano i u ovom radu, koji pokazuje da čak 80% pozicija ukrštanja ima značajan ili ekstreman uticaj.
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).
Length of the primary forest roads in the Federation of BiH is 11.821,00 km that includes the categories of public and forest truck roads. Cantonal Public companies for forest management in the ...Federation of BiH are responsible for the design, construction and maintenance of forest truck roads. The starting point in the analysis related to forest truck roads is to determine the quality and quantity of the existing forest road network. This paper deals with data for all forest truck roads in the territory of Federation of BiH that in total includes 2.907 forest truck roads. The following data were collected and analysed: pavement type, pavement width, longitudinal slope and traffic load per year per 24 h. The analysis of these elements can serve as the basis for categorizing of forest truck roads into primary, secondary and access roads, as well as starting point in planning process related to the maintenance works and future forest road construction.
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).
This paper presents the research results of the Ecotrac 55V skidding productivity in mountainous area of forest compartment 89, Management Unit »Igman« in Bosnia and Herzegovina. The work and time study was applied. »Snap-back chronometry« method was used for the measurement of work category duration. Work organization at the research area was 1+1, driver and assistance worker. A skidder was used for the extraction of conifer wood (fir, Norway spruce and Scots pine). Assortment processing method was applied. The following influence factors were recorded: condition of the tractor road (surface), skidding distance, winching distance, number of pieces in the load, volume of the load and longitudinal inclination of the tractor road. The duration of work operation depending on influence factors was established by applying multiple regression analysis. Total work time was divided into productive work time and delay time. The share of productive time in the total work time was 38.75 %, while the share of delay time was 37.56 %. The standard times and daily skidding outputs were expressed depending on the skidding distance, while average values were used for other influence factors. The standard time was between 8.34 min/m3 and 17.65 min/m3 for skidding distances from 100 m to 900 m. Daily skidding output was between 57.58 m3/day and 27.20 m3/day for skidding distances from 100 m to 900 m. It was found that there is a possibility of increasing skidder productivity by applying better work organization and reducing the share of delays in total work time, especially delays due to organizational and personal reasons (meal time and delays due to rest and personal needs of workers).
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.
U pridobivanju drva u BiH, u fazi sječe i izrade, motorna pila lančanica predstavlja glavno sredstvo rada. Cilj istraživanja je utvrditi potrošnju goriva i maziva motornih pila Husqvarna 365 i Dolmar PS – 7310, pri sječi i izradi šumskih drvnih sortimenata na području P.J. Šumarija „Zavidovići“, odjel 203. Kod mjerenja potrošnje goriva i maziva korištena je volumetrijska metoda s preciznim određivanjem sadržaja goriva i maziva u spremnicima motorne pile. U sklopu istraživanja ukupno je posječeno 140 stabala hrasta kitnjaka (po 70 stabala je posječeno sa motornim pilama Husqvarna 365 i Dolmar PS – 7310). Prsni promjer posječenih stabala kretao se od 15 do 84 cm, dok se visina posječenih stabala kretala u rasponu od 10,3 do 37,2 metara. Ukupni obujam izrađenih sortimenata iznosio je 180,11 m3. Izmjerena prosječna potrošnja goriva po obujmu izrađenih sortimenata za stabla koja su posječena motornom pilom Husqvarna 365 iznosi 0,306 L/m3 i veća je za 0,042 L/m3 u odnosu na motornu pilu Dolmar PS – 7310, sa potrošnjom od 0,264 L/m3. Prosječna potrošnja maziva izrađenih sortimenata za stabla posječena motornom pilom Husqvarna 365 iznosi 0,102 L/m3 i veća je za 0,012 L/m3 u odnosu na motorn pilu Dolmar PS – 7310, sa prosječnom potrošnjom 0,09 L/m3. Na osnovi provedenih istraživanja može se zaključiti da za dane uvjete rada postoje razlike u potrošnji goriva i maziva između ova dva tipa motornih pila, a koje statistički nisu značajne.
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