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Poršinsky Tomislav, PhD. Prof.

Looking Forward to the 45th International Symposium FORMEC 2012

volume: 33, issue: 1

Productivity Models for Operational Planning of Timber Forwarding in Croatia

volume: 33, issue: 1

110 Years of University Forestry Education in the Republic of Croatia (p.109-112)

volume: 29, issue: 2

Are We on the Right Path? (p.1-4)

volume: 29, issue: 1

Methodology for Development of Secondary Forest Traffic Infrastructure Cadastre (p.75-83)

volume: 29, issue: 1

Forest road network in the Republic of Croatia ? Status and perspectives

volume: 28, issue: 1

Comparison of two approaches to soil strength classifications

volume: 27, issue: 1

Skidding of fir roundwood by Timberjack 240C from selective forests of Gorski Kotar

volume: 26, issue: 1

Recent Challenges of Forest Engineering Academic Education

volume: 34, issue: 1

Modelling of Downhill Timber Skidding: Bigger Load – Bigger Slope

volume: 37, issue: 1

Integrated Oak Timber Protection from Ambrosia Bark Beetles: Economic and Ecological Importance in Harvesting Operations

volume: 37, issue: .2

Current State and Improvement Potential of Forestry Workers Training in Croatia

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.

Round Wood Waste and Losses – Is Rationalisation in Scaling Possible?

volume: issue, issue:

The term »loss« should be distinguished from the term »waste« commonly used by forestry practitioners to indicate the difference between gross volume (planned production based on official tariffs) and net volume (produced timber volume) of trees. Volume loss in round wood refers to the difference between the actual volume of round wood and the volume determined based on the prescribed method of measurement and calculation. As a result of prescribed scaling methods and calculations, volume losses appear due to 1) used volume equations, 2) prescribed method of measurement (i.e. measurements of length and mid-length diameter) and 3) deduction of double bark thickness. In Croatia, round wood is cross-cut and transported with bark, while logs are measured and sold without bark. In this way, the bark is an unnecessary ballast in production, but has many possible applications such as energy source, in the production of wooden boards in construction, in nurseries and horticulture, etc. The research was conducted on 225 butt-logs of sessile oak (Quercus petraea (Matt.) Liebl.) ranging in diameter classes from 27.5 cm to 67.5 cm from even-aged forests in the central part of Croatia. Deduction of double bark thickness caused a higher average loss in the volume when using Huber’s equation at 14% and when using Riecke-Newton’s equation at 13.5%. In both volume estimation methods, the loss due to double bark thickness was slightly reduced exponentially as the diameter of but-logs increased. The determined dependence of the bark thickness on diameter of butt-logs over bark indicates the need for correction of the bark deduction tables that are in operational use in Croatian forestry and are provided by trading practices, and since they are not the result of scientific research, they lead to unfair payment between sellers and buyers of round wood. Comparison analysis of the simulation of butt-logs indicated that the introduction of Riecke-Newton’s equation for estimating the volume of commercially important assortments in Croatian forestry is justified. The use of Riecke-Newton’s equation in these terms leads on average to a 6.6% higher volume of butt-logs than the use of Huber’s equation for estimating the volume of assortments.

Round Wood Waste and Losses – Is Rationalisation in Scaling Possible?

volume: 41, issue:

The term »loss« should be distinguished from the term »waste« commonly used by forestry practitioners to indicate the difference between gross volume (planned production based on official tariffs) and net volume (produced timber volume) of trees. Volume loss in round wood refers to the difference between the actual volume of round wood and the volume determined based on the prescribed method of measurement and calculation. As a result of prescribed scaling methods and calculations, volume losses appear due to 1) used volume equations, 2) prescribed method of measurement (i.e. measurements of length and mid-length diameter) and 3) deduction of double bark thickness. In Croatia, round wood is cross-cut and transported with bark, while logs are measured and sold without bark. In this way, the bark is an unnecessary ballast in production, but has many possible applications such as energy source, in the production of wooden boards in construction, in nurseries and horticulture, etc. The research was conducted on 225 butt-logs of sessile oak (Quercus petraea (Matt.) Liebl.) ranging in diameter classes from 27.5 cm to 67.5 cm from even-aged forests in the central part of Croatia. Deduction of double bark thickness caused a higher average loss in the volume when using Huber’s equation at 14% and when using Riecke-Newton’s equation at 13.5%. In both volume estimation methods, the loss due to double bark thickness was slightly reduced exponentially as the diameter of but-logs increased. The determined dependence of the bark thickness on diameter of butt-logs over bark indicates the need for correction of the bark deduction tables that are in operational use in Croatian forestry and are provided by trading practices, and since they are not the result of scientific research, they lead to unfair payment between sellers and buyers of round wood. Comparison analysis of the simulation of butt-logs indicated that the introduction of Riecke-Newton’s equation for estimating the volume of commercially important assortments in Croatian forestry is justified. The use of Riecke-Newton’s equation in these terms leads on average to a 6.6% higher volume of butt-logs than the use of Huber’s equation for estimating the volume of assortments.

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Web of Science Impact factor (2018): 2.258
Five-years impact factor: 2.197

Quartile: Q1 - Forestry

Subject area

Agricultural and Biological Sciences

Category/Quartile

Forestry/Q1