Forest Machinery and Mechanization

A special issue of Forests (ISSN 1999-4907). This special issue belongs to the section "Forest Operations and Engineering".

Deadline for manuscript submissions: closed (25 April 2024) | Viewed by 11246

Special Issue Editors


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Guest Editor
Engineering and Forest Techniques, Department of Forest Utilization, Faculty of Forestry, University of Agriculture in Krakow, Al. 29 Listopada 46, 31-425 Kraków, Poland
Interests: soil physics; terramechnics; forest technique; container nursery; automation and robotization; renewable energy sources
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Engineering and Forest Techniques, Department of Forest Utilization, Faculty of Forestry, University of Agriculture in Krakow, Al. 29 Listopada 46, 31-425 Kraków, Poland
Interests: environmental impact assessment; water quality; soil science; environment; geochemistry; trees; fertilizers; environmental analysis; water science; precipitation; sustainability; plants
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department of Forestry Technologies and Construction, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, 6 Suchdol, 165 21 Prague, Czech Republic
Interests: forest harvesting; forest mechanization; ergonomics and occupational safety; utilization of biomass
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department of Environmental and Forestry Technology, Technical University in Zvolen, Zvolen, Slovakia
Interests: forestry; agricultural engineering; automotive engineering; mechanical engineering
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The rapid development of technology, combined with an increase in the demand for wood and reduced access to cheap labour, has resulted in significant progress in the construction of machines used in forestry in the last few decades. This has resulted in significant progress in the production, acquisition and processing of wood used in forest management. Automation and robotization are concepts that nowadays are often associated with forestry. This Special Issue aims to present the achievements in the field of modern technical and technological solutions that have recently appeared in forest management, with a particular emphasis on automation and robotization.

Potential topics include, but are not limited to, the following:

  • New design solutions in forest machines;
  • Automation and robotization in forestry;
  • Measuring systems for monitoring work, testing forest machines and their performance;
  • Electronics and computer science in forestry and in forest machines.

Dr. Mariusz Kormanek
Prof. Dr. Stanisław Małek
Dr. Jiří Dvořák
Prof. Dr. Jozef Krilek
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Forests is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • automation
  • robotization
  • electronics
  • measurement systems
  • new forest machines

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Published Papers (11 papers)

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Research

11 pages, 1721 KiB  
Article
The Effect of Technological Progress on Yarder Productivity: An Example from the Bulgarian Mountains
by Raffaele Spinelli, Sotir Glushkov, Erik Findeisen, Dimitar Boyadzhiev and Ivailo Markoff
Forests 2024, 15(5), 780; https://doi.org/10.3390/f15050780 - 29 Apr 2024
Viewed by 642
Abstract
In recent years, a significant import of modern tower yarders has been registered in Bulgaria, where official productivity standards are routinely used for operational planning and control. Given the higher potential of the newer yarder models, the Bulgarian forestry sector has started a [...] Read more.
In recent years, a significant import of modern tower yarders has been registered in Bulgaria, where official productivity standards are routinely used for operational planning and control. Given the higher potential of the newer yarder models, the Bulgarian forestry sector has started a review of the older productivity standards dating back to the 1970s. This new endeavor has offered an ideal opportunity for gauging the effect of technological progress in yarder technology. Therefore, the authors have used the very first results achieved during the development of the new standards for conducting a preliminary quantitative comparison between older and newer yarder types. Modern yarders (e.g., Konrad Mounty 4000) are much faster than the older ones (e.g., Koller K300), and their time consumption per cubic meter is half as large, especially on longer distances. At short distances, however, their performance evens out. Regardless of the distance, the installation time of the Konrad Mounty 4000 is twice as short. As they are largely automated, the new machines can be manned by smaller crews (e.g., two workers instead of three) and are easier and safer to operate. Finally, the new machines are equipped with built-in loaders and processors, which allows them to integrate delimbing, crosscutting and stacking within the same work cycle. With older models, a separate team must be deployed for those tasks. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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15 pages, 4345 KiB  
Article
Modal Variability of Ginkgo Seed–Stem System Based on Model Updating
by Jie Zhou, Linyun Xu, Hongping Zhou, Rongshan Zhang, Zhicheng Jia, Fubao Zhang, Yue Zhang, Juan Chen and Cheng Zhang
Forests 2024, 15(1), 178; https://doi.org/10.3390/f15010178 - 15 Jan 2024
Viewed by 836
Abstract
An accurate simulation model is crucial for the analysis of the correct modal information of the ginkgo seed–stem system (ginkgo subsystem). This underpins the provision of technical rationale for efficient and low-damage precision vibrational harvesting operations in ginkgo cultivation. In this study, [...] Read more.
An accurate simulation model is crucial for the analysis of the correct modal information of the ginkgo seed–stem system (ginkgo subsystem). This underpins the provision of technical rationale for efficient and low-damage precision vibrational harvesting operations in ginkgo cultivation. In this study, based on the modal parameters of the ginkgo subsystem, a finite element model updating method is proposed to correct the elastic modulus of the stem with the natural frequency of the first bending mode. The large difference in the modal results calculated before and after model updating reveals that model updating is a critical step in the finite element analysis of crop subsystems. Then, an uncertainty parameter modeling method is proposed to investigate the modal variability of the ginkgo subsystem by finite element analysis. The results show that the stem length is a key parameter affecting the variability of natural frequencies, and the seed weight is a minor parameter. The variability of the ginkgo seed’s gravity center offset has a negligible effect on the natural frequencies of the system. The first natural frequency of the ginkgo subsystem can be utilized for vibrational harvesting. In addition, since the difference between the upper and lower limits of the first natural frequency of the ginkgo subsystem does not exceed 1 Hz, a specific excitation frequency can cause most ginkgo subsystems to resonate. This result facilitates the determination of precise excitation frequencies for efficient and low-damage ginkgo vibrational harvesting, ensuring both economic and ecological benefits in the management of ginkgo plantations. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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21 pages, 8799 KiB  
Article
Linear Cutting Performance Tests and Parameter Optimization of Poplar Branches Based on RSM and NSGA-II
by Liang Zhao, Weidong Yuan, Linyun Xu, Shouxiang Jin, Wangbin Cui, Jiangkun Xue and Hongping Zhou
Forests 2024, 15(1), 146; https://doi.org/10.3390/f15010146 - 10 Jan 2024
Cited by 1 | Viewed by 894
Abstract
To reduce the cutting force and cutting energy consumption during the operation of tree-climbing pruning machines for poplar trees, a linear cutting test bench device for branches was designed according to the growth characteristics of poplar branches and pruning forestry requirements in this [...] Read more.
To reduce the cutting force and cutting energy consumption during the operation of tree-climbing pruning machines for poplar trees, a linear cutting test bench device for branches was designed according to the growth characteristics of poplar branches and pruning forestry requirements in this study. Firstly, the cutting mechanical analysis of poplar branches was carried out to explore the significance parameters affecting the cutting force, and then the cutting performance test and parameter optimization of poplar branches was carried out through the response surface method (RSM). The test results indicated that cutting speed, tool edge angle and tool back angle had significant effects on the ultimate shear stress, cutting power consumption per unit area, and the branch damage rate of poplar branches, and the established regression equation demonstrated high goodness of fit. Meanwhile, a second-order regression mathematical model was developed between ultimate shear stress, cutting the power consumption per unit area of the cut and the branch damage rate, and the significance parameter. The non-dominated Sorting Genetic Algorithm II (NSGA-II) was used for multi-objective optimization computation to obtain the optimal combination of cutting parameters as 3.02 m/s for cutting speed, 15° for tool edge angle, and 3° for tool back angle. In this case, the ultimate shear stress, cutting power consumption per unit area, and branch damage rate of poplar branches were small, which were 346.63 kPa, 9.35 mJ/mm2, and 12.36%, respectively. Through the test verification, it can be seen that the relative error between the verification test and the predicted value of model was less than 7%. Moreover, under a cutting tool edge angle of 15°, the ultimate shear stress, cutting power consumption per unit area, and branch damage rate were, respectively, reduced by 17.29%, 14.98%, and 34.21% compared with those under a cutting tool edge angle of 20°, which verifies the validity and reliability of the test results and the research method. This study can provide data support and reference for the research and development of energy-efficient poplar tree-climbing pruning equipment and related branch-cutting performance tests. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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17 pages, 9328 KiB  
Article
Field and Laboratory Research of the Rut Development Process on Forest Roads
by Oleg Machuga, Andriy Shchupak, Oleg Styranivskiy, Jozef Krilek, Milan Helexa, Ján Kováč, Tomáš Kuvik, Vladimír Mancel and Pavol Findura
Forests 2024, 15(1), 74; https://doi.org/10.3390/f15010074 - 29 Dec 2023
Viewed by 732
Abstract
The main tasks of this research are an extended analysis of the technological rut formation process’s geometric, force, and energy characteristics as a result of repeated passage of a forest machine on the soil surface. Existing experimental studies of the rutting process are [...] Read more.
The main tasks of this research are an extended analysis of the technological rut formation process’s geometric, force, and energy characteristics as a result of repeated passage of a forest machine on the soil surface. Existing experimental studies of the rutting process are associated with significant material costs and disruption of the forest ecosystem. The purpose of this study is to obtain similar experimental data in laboratory conditions, as well as establishing the correspondence of these experimental results to the results of field studies. The experiments were carried out on the specialized “soil channel” stand of Technical University in Zvolen (Slovakia), as well as in natural conditions in Brody Forestry of the Lviv Region (Ukraine). Geometric track characteristics were determined by length gauges. Power and energy characteristics of the track development process were determined using dynamometers, ammeters, and voltmeters. The physical and mechanical characteristics of the soil with which the mover interacted were determined by a dynamic hardness tester, a penetrometer, and a moisture meter. The characteristics of rut development processes in natural and laboratory conditions are similar to each other. This makes it possible to carry out a wide range of studies of a wheel with soil on a specialized stand and save considerable money during the implementation of full-scale experiments. So, the process of track development can be analyzed with the help of the geometric, force, and energy characteristics of the “wheel-soil” system obtained on laboratory equipment. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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15 pages, 4808 KiB  
Article
Leachate Tables as a Tool for Monitoring Changes in Physical and Chemical Parameters of the Peat Substrate in the Cells of Nursery Containers
by Michał Jasik, Mariusz Kormanek, Karolina Staszel-Szlachta and Stanisław Małek
Forests 2023, 14(12), 2398; https://doi.org/10.3390/f14122398 - 8 Dec 2023
Viewed by 816
Abstract
Measuring the physical and chemical parameters of substrates in the cells of nursery containers during production is difficult. Monitoring these parameters, however, is required for optimizing the use of substrates and their components in nursery production, specifically important in the progressive reduction in [...] Read more.
Measuring the physical and chemical parameters of substrates in the cells of nursery containers during production is difficult. Monitoring these parameters, however, is required for optimizing the use of substrates and their components in nursery production, specifically important in the progressive reduction in the use of peat. A new solution—leachate tables—for those studies is presented. The leachate tables enable the collection of liquid samples draining from individual cells in nursery containers during long-term irrigation and fertilization. During our 2-month-long experiment, changes in the physical and chemical parameters of the substrate were analyzed, as well as the process of accumulation of elements fed to the substrate via fertilizer and irrigation water. It was found that, due to the different cell volumes, filling the containers with the substrate under the same parameters of vibration and initial moisture resulted in different fractions of the substrate ending up inside the cells. In the smaller cells, the larger diameter fraction was dominant, and in the larger cells, the smaller fraction was dominant. This may have influenced the differences in air and water capacity of the substrate in cells of different volumes and confirmed the need for the selection of individual vibration parameters for the containers. In addition, over time, the granulometric composition of the substrate in the containers changed. Along with the systematic administration of elements via fertilization from the sprinkler ramp, their leachate content increased as a result of increased leaching from the substrate. With time, the physical parameters of the substrate in the cells stabilized, which may have affected the accumulation and leaching of elements during irrigation and fertilization. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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14 pages, 5038 KiB  
Article
Analysis of the Water Leakage Rate from the Cells of Nursery Containers
by Mariusz Kormanek and Stanisław Małek
Forests 2023, 14(11), 2246; https://doi.org/10.3390/f14112246 - 14 Nov 2023
Cited by 1 | Viewed by 978
Abstract
In container production, the key issue is proper irrigation and fertilization. Typically, the water required for plant growth is supplied through an irrigation ramp system, which can also perform fertilization. The frequency of irrigation and the amount of water supplied by the ramp [...] Read more.
In container production, the key issue is proper irrigation and fertilization. Typically, the water required for plant growth is supplied through an irrigation ramp system, which can also perform fertilization. The frequency of irrigation and the amount of water supplied by the ramp depends on several factors, such as the species of plants grown, the container used, the substrate, and atmospheric factors accompanying production. For effective irrigation, the substrate in the container cell must retain the supplied water long enough for plant absorption. However, any excess water should drain from the container. To optimize irrigation, it is important to determine the parameter of the water outflow speed from the container cell, which is difficult to determine. This work proposes a new solution for a station that can measure the water outflow speed from various container cells (patent application P.443675 2022). In tests, the water outflow speed was assessed for two Styrofoam container types (V150—650/312/150 mm, 74 cells, and 0.145 dm3 cell volume; and V300—650/312/180 mm, 53 cells, and 0.275 dm3 cell volume). Both were filled with a peat and perlite substrate (95/5%) using the Urbinati Ypsilon line (V150 substrate moisture 75.7 ± 1.1%, and V300 75.9 ± 2.1%, efficiency of the line 400 containers∙h−1, vibration intensity of the vibrating table—maximum acceleration 12 G). The results indicated that the water outflow speed varied between container types. The V300 container had a higher outflow speed (0.0344 cm·s−1) compared to the V150 (0.0252 cm·s−1). This discrepancy may be due to differences in dry bulk density, with a correlation of r = −0.523. The V300 had a lower actual and dry bulk density (0.418 g·cm−3; 0.079 g·cm−3) compared to V150 (0.322 g·cm−3; 0.103 g·cm−3). This highlights the need for individual selection of parameters on the backfilling line for different container types when filling. Using identical parameters for diverse containers can lead to varying substrate volume densities, impacting water outflow rates. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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14 pages, 5384 KiB  
Article
The Influence of Vibration and Moisture Content on the Compactness of the Substrate in Nursery Container Cells Determined with a Multipenetrometer
by Mariusz Kormanek, Stanisław Małek and Jacek Banach
Forests 2023, 14(9), 1750; https://doi.org/10.3390/f14091750 - 29 Aug 2023
Cited by 1 | Viewed by 774
Abstract
An important problem of container nurseries is ensuring equal and favorable growth conditions for cultivated plants. This can be achieved by ensuring the physical parameters of the substrate used to grow seedlings in individual cells of the container are similar. The nursery container [...] Read more.
An important problem of container nurseries is ensuring equal and favorable growth conditions for cultivated plants. This can be achieved by ensuring the physical parameters of the substrate used to grow seedlings in individual cells of the container are similar. The nursery container is filled with a specially composed substrate through an automated line. Quickly controlling the parameters related to the quality of substrate filling presents a significant problem, as it requires the ongoing correction of the filling module settings (e.g., extending the vibration time or changing the vibration amplitude). To address this issue, it would be helpful to determine the compactness of the substrate, which can be easily measured using a penetrometer. This paper presents a prototype automated station, known as a multipenetrometer, designed for the simultaneous testing of compactness in 15 selected container cells. The prototype was put to the test at the Nursery Farm in Sukowo, where two types of polystyrene containers (V150—650/312/150 mm; 74 cells; and 0,148 cm3 cell volume and V300—650/312/180 mm; 53 cells; and 0.275 cm3 cell volume) were filled with peat–perlite substrate on the Urbinati Ypsilon automated line. This study investigated the influence of substrate moisture (two levels—70 and 75%) and vibration intensity (two levels—8 and 12 G) of the vibrating table on its compactness within the individual cells of the nursery container. The results indicated that with an increase in substrate moisture and vibration intensity, the compactness of the substrate increased, and the variation in compactness between individual cells decreased. Notably, the V300 containers, with a larger cell volume (265 cm3), experienced a higher level of change compared to the V150 containers (145 cm3). Despite the use of substrate compaction techniques based on the experience of line operators filling containers, the coefficient of variation between the compactness of the substrate in individual cells of the container remained at 30%. Based on the findings, it was confirmed that the optimal parameters for filling V150 and V300 containers with peat–perlite substrate on the Urbinati line, at a filling capacity of approximately 400 containers h−1, are a moisture content of around 75% and a maximum vibration intensity of 12 G. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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12 pages, 1306 KiB  
Article
Analysis of the Operating Parameters of Wood Transport Vehicles from the Point of View of Operational Reliability
by Ján Kováč, Igor Gregor, Ján Melicherčík and Tomáš Kuvik
Forests 2023, 14(7), 1511; https://doi.org/10.3390/f14071511 - 24 Jul 2023
Cited by 1 | Viewed by 871
Abstract
The aim of the research was to create a universal system for monitoring and evaluating the operating parameters of the haulage vehicles used for the haulage of wood with self-maintenance. The article presents partial results from the entire research. Data for research into [...] Read more.
The aim of the research was to create a universal system for monitoring and evaluating the operating parameters of the haulage vehicles used for the haulage of wood with self-maintenance. The article presents partial results from the entire research. Data for research into the operational reliability of IVECO, SCANIA, and TATRA vehicles were obtained from the real-world operating conditions of two companies dealing with the mining/transportation process. Information from the operating conditions was obtained according to the test plan [n, R, t], according to which n objects were simultaneously tested, and the objects that were damaged during the tests were replaced with new ones; the tests ended after the test time t for each of the n positions. Based on the results and statistical analyses, it can be said that the best operational reliability is achieved by IVECO, followed by SCANIA, and only then by TATRA. The resolution of the above conclusions in operating conditions will contribute to the efficiency of the operation of the investigated facilities and the extension of the technical life of the means of transportation. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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14 pages, 7049 KiB  
Article
Analysis of Cutting Forces in Cross-Sawing of Wood: A Study of Sintered Carbide and High-Speed Steel Blades
by Jozef Krilek, Ján Melicherčík, Tomáš Kuvik, Ján Kováč, Arkadiusz Gendek, Monika Aniszewska and Jan Mareček
Forests 2023, 14(7), 1395; https://doi.org/10.3390/f14071395 - 9 Jul 2023
Cited by 1 | Viewed by 1154
Abstract
This research deals with the processing of wood using a circular saw, which is associated with several risks and factors that affect the wood-splitting process. One of them is the wear of the teeth of the saw blade that change the magnitude of [...] Read more.
This research deals with the processing of wood using a circular saw, which is associated with several risks and factors that affect the wood-splitting process. One of them is the wear of the teeth of the saw blade that change the magnitude of the cutting forces. The aim of this study is to compare real measured values and theoretical values when processing Norway spruce wood using two types of saw blades, i.e., sintered carbide (SC) and high-speed steel (HSS), with a diameter of 600 mm and 54 and 56 teeth, respectively. Experimental measurements were carried out on a special test device with the possibility of moving the tested wood into the cutting devices and a simple saw blade replacement system. The results of the contributions show significant differences, based on defined factors which represent the cutting and feed speed, which are supported by FEM analysis of cutting forces in the process of cutting wood—when changing the design of the saw blade. The results of the experiment show that the cutting conditions (cutting speed and feed speed) do not have a significant effect on the size of the cutting forces. The theoretical and real stress values for HSS discs ranged from 14 to 22 MPa. Significantly larger differences were recorded for discs with SC, where the real values of the maximum stresses were around 14 MPa and the theoretical ones around 25 MPa. When cutting spruce with a disc with SC slices, the maximum values of the theoretical cutting forces were in the range of 76 to 94 N and the maximum values of the measured cutting forces were in the range of 40 to 44 N. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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11 pages, 5843 KiB  
Article
Energy Consumption and Cutting Performance of Battery-Powered Chainsaws
by Zdravko Pandur, Marin Bačić, Marijan Šušnjar, Matija Landekić, Mario Šporčić, Branimir Jambreković and Kruno Lepoglavec
Forests 2023, 14(7), 1329; https://doi.org/10.3390/f14071329 - 28 Jun 2023
Cited by 1 | Viewed by 1150
Abstract
The aim of this research is to measure the energy consumption and compare the cutting performance of three types of battery-powered chainsaws (Stihl MSA 200, Stihl MSA 220, and Stihl MSA 300). Tested chainsaws were powered by two different battery packs (Stihl AP [...] Read more.
The aim of this research is to measure the energy consumption and compare the cutting performance of three types of battery-powered chainsaws (Stihl MSA 200, Stihl MSA 220, and Stihl MSA 300). Tested chainsaws were powered by two different battery packs (Stihl AP 300 S and Stihl AP 500 S) with different energy capacity and output current when cutting two wooden beams, European beech (Fagus sylvatica L.) and black locust (Robinia pseudoacacia L.) with different densities and moisture content. Energy consumption was measured using a multimeter built-in battery charger housing, and consumed energy was noted in watt-hours. Each individual cut was recorded with an action camera at 60 frames per second, and the duration of the cuts recorded in centiseconds was observed on the obtained recordings. Results show significant differences in energy consumption and cutting duration between individual chainsaw/battery combinations. Energy consumption ranged from 2.45 to 4.50 Wh per cut for beech (Stihl MSA300E_AP500S and Stihl MSA220_AP300S, respectively) and from 3.10 to 5.00 Wh per cut for black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP500S, respectively). Duration of the cut ranged from 3.48 to 9.24 s per cut for beech (Stihl MSA300M/H_AP500S and Stihl MSA220_AP300S, respectively) and from 3.74 to 9.35 s per cut for the black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP300S, respectively). In general, it can be concluded that more powerful chainsaw/battery combinations (Stihl MSA300_AP500S) consumed less energy per cut and had better cutting performance (shorter cut). In that regard, more powerful chainsaws had greater cutting efficiency, i.e., more cuts on one charge (battery) but shorter cutting time on one charge. The effect of tree species (fresh-sawed beech/air-dried black locust) on energy consumption and cutting performance is absent on the most powerful chainsaw/battery combinations. Today, lithium-ion batteries still have 70 times less energy density than petrol. However, if there is a significant increase in the energy density of the batteries in the coming times, battery chainsaws will most certainly displace petrol chainsaws from use in the future. Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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15 pages, 3473 KiB  
Article
Accuracy of Double Bark Thickness Estimation Methods Used in Spruce—(Picea abies L. Karst) Timber Production in Czechia
by Martin Jankovský, Zuzana Dudáková, Michal Allman, Jiří Dvořák, Prince Opoku Peseu and Sandra Paola García Jácome
Forests 2023, 14(5), 1026; https://doi.org/10.3390/f14051026 - 16 May 2023
Viewed by 1135
Abstract
The accurate estimation of bark thickness is important for foresters for several reasons. It is crucial for timber volume estimation and can help improve the quality of forestry records, and bark has a growing commercial importance as a high-value bioresource. The problem is [...] Read more.
The accurate estimation of bark thickness is important for foresters for several reasons. It is crucial for timber volume estimation and can help improve the quality of forestry records, and bark has a growing commercial importance as a high-value bioresource. The problem is that models such as the Czech Cubic Tables (CCT) polynomial model are frequently unique. Furthermore, the official method requires rounding down the midspan over-bark diameter (DOB) to the nearest centimetre to estimate the double bark thickness (DBT) and merchantable timber volume. Therefore, we verified the significance of the effects of rounding down the midspan DOB on DBT using a dataset of 438 recently harvested Norway spruce (Picea abies L. Karst.) logs from the Central Bohemian region. The correlation analysis showed that for measured data without rounding down the diameters, the variability of the DBT was able to explain only 8% of the DOB variability. As for the rounded-down data, the coefficient of determination was slightly higher, reaching 9%. The paired-samples T-tests showed a significant difference between the DBT as calculated directly from measured data and that from the rounded-down over-bark diameters (p < 0.05). The polynomial and linear models underestimated the DBT (2.24 and 1.75 mm on average, respectively) on measured data. In contrast, for data from the rounded-down DOB, the models overestimated the DBT (2.70 or 3.18 mm on average, respectively). Full article
(This article belongs to the Special Issue Forest Machinery and Mechanization)
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