The influence of fragmented private forest property on mechanized cutting

Prikazani so rezultati študije potencialov prostorskega združevanja zasebne gozdne posesti v procesu pridobivanja lesa z vidika učinkovitosti rabe tehnologije kratkega lesa. Učinkovita raba tehnologije kratkega lesa je povezana predvsem s količinsko in prostorsko koncentracijo sečenj, kar je velik problem pri večini slovenskih gozdov v zasebni lasti s prevladujočo drobno posestno strukturo. Velikostna struktura slovenske zasebne gozdne posesti je obravnavana z vidika kriterijev za rabo sodobnih tehnologij kratkega lesa, ki jih uporabljajo v tujini, kjer je ta tehnologija že uveljavljena. Izdelali smo model, ki glede na razdrobljenost posesti, število lastnikov in gozdnih fondov teoretično vrednoti možnosti prostorskega združevanja zasebne gozdne posesti oz. parcel, ki zadostijo pogojem za rabo sodobnih tehnologij kratkega lesa. Zza sedanje in modelno stanje smo analizirali različice z vidika izvedbe pridobivanja lesa in kazalce njene učinkovitosti pri potencialnem skupnem nastopanju v procesu realizacije možnih sečenj. Po gozdnogospodarskih območjih so obravnavane razlike med sedanjim in modelnim stanjem združene zasebne gozdne posesti po kazalcih števila lastnikov, količin in intenziteti možnih sečenj, velikosti delovišč oz. blokov za izvedbo sečenj s tehnologijo kratkega lesa. Med kazalci učinkovitosti rabe sodobnih tehnologij pa so analizirani časi za premik strojev in stroški sečnje glede na vrednosti obravnavanih kriterijev.The paper presents the results of research dealing with potential pooling of private forest property in Slovenia. The aim of pooling fragmented owner structure is to evaluate the potential introduction of mechanized cutting, which demands spatial concentration of forest operation as well as intensitiesof the cutting volume. The fragmented owner structure is evaluated regarding the criteria used in the countries, where mechanized cutting has already been established. Integration of adjacent fragmented owner\u27s properties was carried out, which were determined and selected in view of their suitability for mechanized cutting. The efficiency analyses of cutting operation on fragmented and potential joined private forest property was simulated. The differences between fragmented and potential joined private forest property regarding the number and area of potential working fields, cutting volumes and cutting intensities by forest regions in Slovenia are presented. Manipulation of machinery and costs of cutting operation were used as criteria for the evaluation of cut-to-length technology in both present and potential situations

Učinkovitost obnove gozdov po ujmah na primeru vetroloma v Kidričevem (29.6.2006)

Economic efficiency is one of the many essential demands regarding the technical management of windstorms. The main goal of this paper is to analyze a hypothetical scenario in which a forest owner works independently on windstorm restoration, using his own equipment and work power. Managing windstorm damage is a difficult and dangerous task, although a potentially lucrative endeavour as our investigation shows. A windstorm represents an opportunity for instant profit for forest owners who are independent of regular forest income. Economic damage is greater and longer lasting for owners with large forest properties and for farm households, which depend on regular forest income. We compared two potential scenarios in a wind-damaged area within the 2000-2010 forestry management period. First, we include a hypothetical scenario in which the windstorm did not occur. An inventory of regular thinning as well as simulation of future events based on past dynamics was done. We also performed a second scenario in which we assumed that private owners carry out windstorm restoration alone, although in reality felling has been carried out with short-wood technology (mechanized cutting). The results section presents the possibilities to attain reasonably high yield by dealing with the consequences of a minor windstorm.Ekonomska učinkovitost je ena izmed mnogih nujnih zahtev pri tehničnem odpravljanju škode, ki jo povzročajo gozdne ujme. Glavni namen tega prispevka je analizirati hipotetični scenarij, po katerem se lastnik gozda sam, z lastno opremo in delovno silo, ukvarja z obnovo svojega gozdnega posestva po ujmi. Odpravljanje takšne škode je težka in nevarna naloga, hkrati pa tudi potencialno donosna, kot kažejo naše raziskave. Ujma je namreč priložnost za takojšen dobiček za lastnike gozdov, ki niso odvisni od rednih prihodkov, povezanih z gozdom. Ekonomska škoda je večja in dolgotrajnejša za lastnike velikih gozdnih posestev in kmečka gospodinjstva, ki so odvisna od rednih gozdarskih prihodkov. Avtorja članka sta primerjala dva potencialna scenarija v območju, ki so ga v gozdnogospodarskem obdobju 2000-2010 prizadele gozdne ujme. Najprej vključita hipotetični scenarij, po katerem ujme sploh ni bilo, in napravita popis rednega redčenja ter simulacijo prihodnjih dogodkov na osnovi dotedanje dinamike. Potem se posvetita drugemu scenariju, po katerem se z obnovo gozdov po ujmi ukvarjajo lastniki sami, čeprav je delo dejansko potekalo z uporabo tehnologije kratkega lesa oz. mehanizirane sečnje. Rezultati kažejo na možnost, da je mogoče dosegati tudi sorazmerno visok prihodek pri odpravljanju posledic manjših vetrolomov

The suitability evaluation of cut-to-length in Slovenia in view of terrain and stand

V prispevku avtorja predstavljata metodo in rezultate študije o možni uporabi strojne sečnje lesa v Sloveniji. Študija je bila narejena z računalniškim modelom, pri katerem smo za vplivne dejavnike uporabili razpoložljive digitalne podatke, od katerih je v največji meri odvisna možnost izvedbe strojne sečnje lesa. Analizirali smo različice strogosti upoštevanja pogojev za izločanje primernih površin. Rezultati študije kažejo, da so velike možnosti povečanja ocene površin kot primerne za rabo strojne sečnje na strmejših terenih ter v sestojih z večjim deležem listavcev.The paper presents the method and results of the study of cut-to length suitability in Slovenia. The study was carried out with the aid of a computer model. Decisive variables and all the available digital forest inventory data were used with then most important cut-to-length limiting factors. The variation of decisive variables was analysed and compared with basic values inorder to determine areas suitable for cut-to-length. The results show great variations as far as the selected areas are concerned, with terrain slope and share of conifers in growing stock as the most important factors in the

Determination of increased forest value in denationalization procedures

Vrednost gozda se poveča zaradi gradnje gozdnih cest. Povečano vrednost gozda je mogoče ugotoviti na podlagi ponovne katastrske klasifikacije gozda. Ta način pa je zamuden in drag. Hitrejši in bolj zanesljiv je izračun na podlagi izračuna skrajšanja spravilne razdalje, ki je posledica novih gozdnih cest. Pri tem si lahko pomagamo z digitalizacijo obravnavanega gozda in prometnic, kar omogoča zanesljiv izračun skrajšanih spravilnih razdalj, ki vplivajo na povečano vrednost gozda.Forest value is increased by forest road construction. We can established increased forest value due to anew cadastral survey. The procedure of cadastral survey is time-consuming and expensive. The other possibility is calculation new shorter skidding distance results by new forest roads. The digitalization of forest area and forest roads under consideration enables accurate calculation of skidding distance. The skidding distance has one of the main influential factor used for forest value determination

The suitability evaluation of cut-to-length in Slovenia in view of terrain and stand

The paper presents the method and results of the study of cut-to length suitability in Slovenia. The study was carried out with the aid of a computer model. Decisive variables and all the available digital forest inventory data were used with then most important cut-to-length limiting factors. The variation of decisive variables was analysed and compared with basic values inorder to determine areas suitable for cut-to-length. The results show great variations as far as the selected areas are concerned, with terrain slope and share of conifers in growing stock as the most important factors in them

Labour costs in diverse forest work conditions and utilization of wood harvesters

Sodobne tehnologije v procesu pridobivanja lesa zahtevajo skrbno analizo stroškov dela. V ta namen so analizirani nekateri tuji modeli računanja stroškov za strojno sečnjo. Predstavljamo program za analizo stroškov strojne sečnje, ki omogoča izdelavo kalkulacij za stroje za sečnjo in nadaljnjo analizo učinkov in stroškov pri različnih pogojih dela. Predvidene so različice za majhne in velike stroje ter za sestoje iglavcev in listavcev. Program omogoča analizo vplivnih dejavnikov na višino stroškov, med katerimi so najpomembnejši operativna stopnja izkoriščenosti strojev, analizirana v odvisnosti od učinkov in premikov stroja med delovišči, velikost delovišč, koncentracija sečenj in povprečno drevo poseka. Poleg navedenih vplivnih dejavnikov je mogoče analizirati tudi vpliv letne stopnje izkoriščenosti stroja na višino stroškov strojnega dela. Analize so pokazale, da se v splošnem pojavijo največje razlike v stroških dela pri kombinaciji koncentracije 30-40 m3/ha in 0,3 m3 povprečnega drevesa poseka.In contemporary wood production technologies, there is an urgent demand for precise forest operation cost analyses. Some examples of cost calculation for mechanized cutting are analyzed. A new computer procedure for cost calculationis presented. The procedure enables forest operation cost calculation and analyses of productivity in different work conditions. Forest operation productivity for small and big harvesters in coniferous and deciduous stands can be selected. The program also enables analyses of influential factors which affect mechanized cutting costs. The most important influential factor is the operational degree of utilization, which is influenced by transfer of machines between work fields, size of work fields, cutting and tree volume. It is also possible to conduct sensitivity analyses of machine utilization expressed in working hours per year. Generally, sensitivity analyses showed that the labour cost differences are highest at the cutting volume of 40-50m3/ha and 0.3 m3 mean tree volume

Prostorski model oskrbe majhnih žag z lesom na območju Alp - študij primera

With wood logistics and forest operation modelling, we have connected a technologic chain of cutting, skidding and road wood transport operations. The goal of the paper is to present the possibilities of simulating forest operation activities including cost flow prediction. The case study regarding wood flow and forest operation cost modelling was conducted in four municipalities located in western Slovenia (bordering to Italy). Input data of forest inventory and basic forest data were used in order to predict the wood flow in the test area. We modelled the available cutting volumes with the capacities of local sinks - notably sawmills. Unbalanced hinterland areas of specific sinks that do not cover the local sink capacities were changed (reduced or enlarged) on account of the adjacent hinterland areas with surplus or shortage of wood volume. The hauling distances and wood volumes for covering the sawmillsć capacities of the adopted (balanced) hinterland areas were studied.S pomočjo modela za logistiko in pridobivanje lesa smo povezali tehnološko verigo oskrbe z lesom od sečnje in izdelave, spravila ter prevoza lesa. Cilj prispevka je predstavitev možnosti predvidevanja (simulacije) aktivnosti v procesu pridobivanja lesa, vključno z vidika njihovih stroškov. Raziskava je bila narejena na primeru štirih občin v zahodni Sloveniji na meji z Italijo. Na izbranem območju je bil uporabljen gozdarski informacijski sistem, vključno z osnovnimi podatki popisa gozdov z namenom napovedovanja pridobivanja in transporta lesa. Modelno smo primerjali razpoložljive količine možnih sečenj s kapacitetami lokalnih porabnikov - predvsem žag. Na osnovi neuravnoteženih razmerij med kapacitetami porabnikov in zaledjem gozdov smo posameznim porabnikom spremenili zaledja (pomanjšali ali povečali) na račun sosednjih zaledij s pribitkom ali pomanjkanjem lesa. Na osnovi sprememb so bili analizirani stroški prevoza lesa

Planning Forest Opening with Forest Roads

The article presents the model for determining inaccessible forest areas by density of forest roads. The model is based on the GIS analysis of the distances between the existing network of public and forest roads and inaccessible forest areas, sizes of excluded forest areas, and forest site potentials. In order to increase forest road density, the following must be done: (1) construct connecting roads to the inaccessible forest areas and (2) construct new forest roads with different density in the excluded inaccessible forest areas. The model provides the minimum size of the inaccessible area located at least 300 m away from the existing forest and public road. The selected inaccessible forest areas are first analyzed according to their size – plot size of at least 30 ha is used as a model default size suitable for economically justified construction of the access road that connects the existing road network to the inaccessible forest area. The analysis showed that there are still 210,385 ha of inaccessible forests in Slovenia according to the model criteria. According to the research of regional units conducted by forest experts and based on the determination of priorities for the next ten-year forest management plan, the construction of 758 km of new forest roads is planned at the national level

USPOREDBA MEHANIZIRANE I RUČNO-STROJNE SJEČE U MJEŠOVITIM SASTOJINAMA JUŽNE SLOVENIJE

By increasing the diversity of conditions influencing the forest operation we are often faced with the dilemma of combining Motor manual and Cut to length technologies. The results of time study and productivity of cutting and skidding operation in mixed stands with a substantial proportion of deciduous trees are presented. Older pole stand was divided into four homogeneous strata in which forest operation was executed by applying two different technologies (motor manual and cut to length), each on two research areas. The objective of this study was to identify the influential factors which could be used as guidelines in the decision support system evaluating the suitability of both technologies. The results show that the mechanized cutting productivity is statistically significantly different for different tree morphological characteristics. In order to set up general guidelines it was established that the productivity in stands with single-trunked, short crown and thin branches processed with Cut-to-length technology is 25% higher than in the comparable stands consisting of multi-trunked trees, deep crowns with thick branches in terms of diameter at breast height structure.Povećanjem raznolikosti uvjeta koji utječu na šumske operacije, često smo suočeni s nesuglasicama između tradicionalnih i modernih tehnologija. U radu su prikazani rezultati studije vremena rada i proizvodnosti sječe i privlačenja drva u mješovitim sastojinama sa značajnim udjelom listača. Starija sastojina podijeljena je na četiri jednaka dijela u kojima su izvedene šumarske operacije primjenom dviju različitih tehnologija (ručno-strojna i strojna sječa i izradba), svaka od njih na dvije površine.Cilj istraživanja bila je usporedba proizvodnosti spomenutih tehnologija i izlučivanje utjecajnih čimbenika koji bi mogli poslužiti kao smjernice u procesu ocjene primijenjenih tehnologija kroz sustav za podršku odlučivanju. Rezultati pokazuju da proizvodnost strojne sječe statistički značajno odstupa između morfološki različitih stabala. U cilju donošenja općih smjernica, ustanovljeno je da je proizvodnost kod CTL tehnologije 25% veća u sastojinama onih stabala koja imaju jedno deblo, kratku krošnju i tanke grane, u odnosu na sastojine stabala koja imaju više debala, dugačku krošnju i deblje grane, ovisno o distribuciji prsnih promjera doznačenih stabala

Harvester operator learnig efficiency analysis

Članek obravnava načine učenja bodočih strojnikov za delo s strojem za sečnjo.Na prvem takšnem primeru v Sloveniji je opisan in analiziran potek učenja s simulatorjem in merjeni so časi posameznih postopkov pri dveh kandidatih. Opisano je delovanje simulatorja za učenje na stroju Timberjack 1270 D in potek enotedenskega tečaja. Narejena je primerjava med kandidatoma glede porabe časa in števila poškodb na virtualnem stroju in sestoju, ki jih je beležil program simulatorja. Podane so usmeritve za prihodnje študije in spremljanje učinkov strojnikov pri delu.The article considers the possibilities of training future harvester operators. The course of learning with a simulator is described and analysed on the first such example in Slovenia. The times of individual processes are measured in two candidates. The paper describes the operation of a learning simulator for work on the harvester Timberjack 1270 D and the proceedings of aone-week course. A comparison between candidates regarding the consumption oftime and number of damages to the virtual machine and the stand is derived from the data recorded by the programme of the simulator. Directions for future studies and monitoring of operatorsć efficiency at work are also given