Template-Type: ReDIF-Article 1.0 Author-Name: Trairat Neimsuwan Author-Workplace-Name: Department of Forest Products, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Kitipong Tangkit Author-Workplace-Name: Department of Forest Products, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Chakrit Na Takuathung Author-Workplace-Name: Department of Forest Engineering, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Nopparat Kaakkurivaara Author-Workplace-Name: Department of Forest Engineering, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Ponthep Meunpong Author-Workplace-Name: Department of Silviculture, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Narinthorn Jumwong Author-Workplace-Name: Forestry Research Center, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Pattama Sangvisitpirom Author-Workplace-Name: Forestry Research Center, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Author-Name: Tomi Kaakkurivaara Author-Workplace-Name: Department of Forest Engineering, Faculty of Forestry, Kasetsart University, Bangkok, Thailand Title: Mechanical and physical properties of three Eucalyptus spp. clones planted in Thailand Abstract: Eucalyptus plantations are an important source of raw materials for the Thai forest products industry. Despite its economic value, only a few noncomprehensive papers have been published about the wood properties and fungal susceptibility of eucalyptus. Our study covered the most commonly used commercial eucalyptus clones with a wide variety of sizes from eastern Thailand. We assumed that the properties of the clones would differ based on the tree sizes. The objectives of this study were to determine the effects of diameter at breast height (DBH), size, and clone type on wood properties and mould susceptibility. The optimal usage of each log characteristic based on the log quality and properties could be used to determine the maximum payoff. The wood properties and log characteristics of five eucalyptus log classes with three clones were investigated. In general, the levels of means and standard deviations were as follows: the modulus of rupture (MOR) was between 39 ± 4.9 MPa and 66 ± 5.4 MPa, and the modulus of elasticity (MOE) was between 14.5 ± 9.7 GPa and 24.0 ± 2.7 GPa. In addition, the compression parallel to the grain was between 28 ± 3.2 MPa and 43 ± 2.4 MPa, and the compression perpendicular to the grain was between 13 ± 0.7 MPa and 19 ± 1.1 MPa. The shear strength parallel to the grain was between 10 ± 0.3 MPa and 14 ± 0.6 MPa. The cleavage and hardness were from 4.7 ± 1.6 N to 7.4 ± 0.9 N and from 3.6 ± 0.3 kN to 6.2 ± 0.6 kN, respectively. The toughness and nail withdrawal were from 27.3 ± 3.5 kN.mm-1 to 50.5 ± 1.0 kN.mm-1 and from 28.56 ± 4.1 N.mm-1 to 34.52 ± 2.8 N.mm-1, respectively. Eucalyptus clone K7 had lower MOR and other mechanical properties than clones K58 and K62 except MOE. When DBH increased, the mechanical and physical property values increased as well. This happened for all clones, and especially when DBH was over 200 mm. The results of this study showed that log characteristics, such as taper, slenderness, and crookedness, should be used for log grading standards and that each fast-growing eucalyptus clone could be applied to different product classes. Keywords: clone K7, clone K58, clone K62, eucalyptus wood, modulus of elasticity (MOE), modulus of rupture (MOR) Journal: Journal of Forest Science Pages: 512-528 Volume: 70 Issue: 10 Year: 2024 DOI: 10.17221/34/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/34/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202410-0001.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:10:id:34-2024-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Dominika Gaj-Gielarowiec Author-Workplace-Name: State Forests, Daleszyce Forest District, Daleszyce, Poland Author-Name: Karol Gielarowiec Author-Workplace-Name: State Forests, Radoszyce Forest District, Radoszyce, Poland Author-Name: Grzegorz Szewczyk Author-Workplace-Name: Department of Forest Utilization and Forest Techniques, Faculty of Forestry, University of Agriculture in Krakow, Krakow, Poland Author-Name: Paweł Tylek Author-Workplace-Name: Department of Forest Utilization and Forest Techniques, Faculty of Forestry, University of Agriculture in Krakow, Krakow, Poland Title: Characteristics of the workplace of harvester operators in Poland Abstract: The objective of the presented research was to create an average image of a harvester operator in Poland and to identify factors influencing the degree of mental workload. We used a survey of environmental assessments of workload. The creation of an electronic survey and the support of a company that indirectly employs operators (State Forests) made it possible to reach a large group of surveyed people. The respondents indicated the occurrence of ailments typical of sedentary work at the researched workstation. These included mainly monotony, back pain and numbness in the upper limbs. Stress at work was felt by the majority of respondents; hence the analyses of mental stress, which also translates into other diseases, should indicate key responses to questions regarding comprehensive ergonomic assessments at the researched workstation. Keywords: ergonomics, harvesting, mental workload, survey research Journal: Journal of Forest Science Pages: 501-511 Volume: 70 Issue: 10 Year: 2024 DOI: 10.17221/49/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/49/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202410-0002.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:10:id:49-2024-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Tamás Ábri Author-Workplace-Name: Department of Plantation Forestry, Forest Research Institute, University of Sopron, Püspökladány, Hungary Author-Name: Zsolt Keserű Author-Workplace-Name: Department of Plantation Forestry, Forest Research Institute, University of Sopron, Püspökladány, Hungary Author-Name: Veronika Honfy Author-Workplace-Name: Department of Plantation Forestry, Forest Research Institute, University of Sopron, Püspökladány, Hungary Author-Name: Attila Borovics Author-Workplace-Name: Department of Forest Tree Breeding, Forest Research Institute, University of Sopron, Sárvár, Hungary Author-Name: Károly Rédei Author-Workplace-Name: Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary Title: Stand structural analyses of grey poplar (Populus × canescens) stands focused on the expected volume in Hungary Abstract: Grey poplar (Populus × canescens) is a natural hybrid of white poplar (Populus alba L.) and Eurasian aspen (Populus tremula L.). It could play a significant role in the afforestation of marginal sites which stretch out on ever more areas due to the negative effects of local climate change. Based on stand structure analyses of grey poplar stands grown on the sandy sites of Hungary, the following relations were found: There is a strong relationship between tree height and stand volume (R2 = 0.7256), as well as between basal area per ha and stand volume (R2 = 0.9158). There is a moderate relationship between diameter at breast height and stand volume (R2 = 0.6175). The results could contribute to a more accurate assessment of applied silvicultural technologies. Keywords: marginal sites, poplars, tree growth, yield modelling Journal: Journal of Forest Science Pages: 539-544 Volume: 70 Issue: 10 Year: 2024 DOI: 10.17221/53/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/53/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202410-0003.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:10:id:53-2024-JFS Template-Type: ReDIF-Article 1.0 Author-Name: Stanislav Novotný Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Josef Gallo Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Vilém Podrázský Author-Workplace-Name: Department of Silviculture, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Economic parameters of the natural forest regeneration in changing conditions - A case study Abstract: Natural regeneration is a crucial factor in improving the economy of forest estates. The presented study analysed the economic parameters of three different approaches to forest regeneration: (i) artificial regeneration with Norway spruce, (ii) a 25% admixture of soil-improving and stabilising species (SSTS), and (iii) natural regeneration. The expenses for these specific operations related to individual regeneration methods were derived. These variants were investigated before the bark beetle calamity (2014) and after the outbreak (2023) for management sets (MS) 531, 551, 571, and 591, i.e. for acidic, nutrient-rich, gleyed, and waterlogged sites of higher elevations. In all cases, natural regeneration decreased expenses by approximately 2 000 EUR.ha-1 (50 000 CZK.ha-1) to 6 000 EUR.ha-1 (150 000 CZK.ha-1). The 25% admixture of SSTS increased the expenses. The proportion of natural regeneration subsequently decreased due to the bark beetle calamity from roughly 40% to 10% in recent years, which is comparable with the Czech Republic as a whole. Keywords: admixture, bark beetle calamity, economic efficiency, Norway spruce Journal: Journal of Forest Science Pages: 529-538 Volume: 70 Issue: 10 Year: 2024 DOI: 10.17221/56/2024-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/56/2024-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-202410-0004.txt Handle: RePEc:caa:jnljfs:v:70:y:2024:i:10:id:56-2024-JFS