volume: 39, issue: 1
In the study, the relationship between operators’ age, experience and mechanized cut-to-length
(CTL) harvesting productivity was examined. The data were five-year follow-up data from 28
operators and 38 CTL harvesters collected from southern Finland. Productivities were converted
to relative productivities and average productivity models were created. Case specific
productivities were compared to modelled values, and productivity ratio models including
separate lower and upper quartile models were produced.
The relative productivity of operators at the age of 45 years in clear cuttings was 17.8%
higher and in thinnings 14.9% higher than that of operators at the age of 25 years. The relative
lower quartile productivity increased from operators aged 25 to operators aged 45 years by
38.6% in clear cuttings and 29.4% in thinnings. The relative productivity of operators having
experience of 20 years was 23.6% higher in clear cuttings and 16.2% higher in thinnings than
that of operators having experience of 3 years. Operators’ experience of 20 years produced
43.1% better lower quartile relative productivity in clear cuttings and 29.1% in thinnings
compared to 3 years’ experience. The relative upper quartile productivity was 5.7% higher in
clear cuttings for operators aged 45 years than for operators aged 25 years, but otherwise, there
was no statistical correlation between upper quartile productivity and age or experience.
As a conclusion, CTL harvester operators’ average productivity increases slowly after the
initial learning phase up to 15 years of experience. The peak productivity was uncorrelated to
age or experience, but the experience raised the bottom productivity values.
volume: 39, issue: 1
Within the fuel wood supply chain, comminution and transport have been identified as processes
with the highest costs, energy consumption and emissions. The coordination of comminution
and transport aimed at avoiding operational delays is also complex. Nevertheless,
the use of forest biomass helps to reduce the effects of climate change and produces an additional
income, especially in rural areas. About 20 years ago, at the beginning of the industrial
forest fuel utilisation, the focus of the research was on developing and analysing adequate
supply chains and machines. Nowadays, as state-of-the-art systems have been established, the
focus is on improving the efficiency of the processes and the quality of the products. This paper
provides a review of research trends of the last ten years focusing on comminution and transport
of forest biomass in Europe.
Comminution should become more efficient by analysing the effects of wood characteristics on
chipper performance and product quality, by tailoring chipper configuration according to those
findings and by introducing mechanical devices for improving the quality of chips. Transport
processes have the potential to become more efficient if the configuration of trucks is adapted
according to operational and legal requirements, and when considering moisture content
management. Finally, economic and environmental assessment of supply chains was made by
several studies. Future research is expected to focus on customizing the product quality according
to user’s requirements and on optimising the coordination of chipper and truck by
simulation and automatization tools.
volume: 39, issue: 2
This paper discusses the key issues of forestry workers training in Croatia, especially dealing
with the providers of vocational training, their profile, training procedures and measures
necessary for training improvement. A combined approach of literature review, internet search
and questionnaire of training providers was applied in order to collect data on training programs
conducted in Croatia. The research was conducted during 2016, and it included 94
legal entities authorized for occupational safety training in the Republic of Croatia, with respect
to safe working practice training and vocational training for operating machinery (chainsaw
and/or skidder). The analysis used basic descriptive statistics.
Research results showed that 30.85% of the analyzed legal entities provide only training for
safe working practice, 15.96% provide both trainings – safe work practice and vocational
training for operating machinery, 5.32% of the analyzed entities provide only vocational
training for operating machinery, 31.91% do not carry out any form of training in forestry,
while 15.96% refused to answer questions. On the other hand, 15.56% of the legal entities,
which do not carry out any training or did not answer these questions, have on their official
website services posted for vocational training in operating machinery (chainsaw and/or skidder).
The key findings of the conducted research have pointed out the great heterogeneity
amongst providers of forestry workers training, and certain reductions or limitations in the
current training programs, both from the aspect of duration of the theoretical and practical
training, and the use of non-transparent criteria and standards in the assessment of training.
As an example of successful solution in forestry workers training, European Chainsaw Standard
model (ECS) is shortly presented in the paper. Discussion and conclusion sections provide
an overview of legislative and organizational requirements for the application of previously
developed European model (ECS) in developing the certification system for training of forestry
workers in Croatia.
volume: 39, issue: 2
Economic analysis of even-aged fir stand management was illustrated using the example of the
forests of the Croatian Dinaric region, as well as their transformation into more stable unevenaged
structures. Two scenarios (even-aged, uneven-aged) were simulated against the backdrop
of the existing forest stand structure of future forest stand management during a 140-year
period using forest growth modeling software MOSES version 3.0 in order to identify economic
differences amongst different scenarios both at stand level and at forest level. The research
included forest management analysis throughout the transformation period and subsequently
the continuation of balanced state forest management. Moreover, the research also
provided the opportunity of forest purchase within the price range from 1000 to 12,500 EUR/ha,
amid assumed fluctuation of selling prices of timber assortments throughout the simulation
period. Discount rates from 1% to 5% were used during the economic analysis. The research
findings showed that, according to harvesting costs, Net Present Value and Internal Rate of
Return, uneven-aged forest management system, including the transformation period, achieved
superior economic results, albeit at discount rates that exceeded 1.24%. The conclusion was
reached that, according to all economic criteria, uneven-aged mixed silver fir-beech management
system is preferred compared with the pure even-aged silver fir management.