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Effect of Fungus Meripilus giganteus (Pers.) P. Karst. on Occurrence and Development of False Heartwood and Rot in Fagus sylvatica L. Round Wood

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Common beech is one of the most widespread and important European tree species, widely used in timber industry and for energy production. Under specific set of complex factors, it facutatetivly develops false heartwood, which considerably decreases market demand and value of processed logs. Due to its properties, false heartwood is more susceptible to attack of wood decay fungi, which leads to further loss of wood quality and value. One of the most common fungi able to cause heart rot in beech is Meripilus giganteus, known for its spread in the basal parts of the tree, where it can affect most valuable sections of round wood. The aims of this study were to monitor the distribution of fungus and appearance of its fruiting bodies in research area, and to analyze the extent of fungus impact on shape and size of false heartwood and occurrence and length of rot in infected trees, while taking into account the observed stem damage as a possible influential factor. Fruiting bodies occurrence, life span and position on a tree were monitored during a six-year period. For trees with confirmed infection, stem damage was evaluated and appointed to one of four size classes. False heartwood shape and share in associated stem cross-section were observed and measured on 1–4 cross-sections per tree at different heights, and compared between infected and uninfected trees. If present, length of wood decay extent on butt-log was measured. The obtained results confirmed increased susceptibility of mature trees to infection, which seemed to occur mostly via roots from where mycelium spread into stem base. It was found that Meripilus giganteus has a significant impact on enlargement and change of FH shape from cloud- to star-like, up to approximately 5 m of the stem height, thus causing devaluation of the first assortments. The presence of rot was confirmed on the majority of infected trees, extending averagely 0.5 m into the first processed log, causing the loss of utilizable volume and thus the value of round wood. Stem damage category showed no significant effect on false heartwood or rot, supporting the prevailing impact of the fungus.

Bearing Capacity Standards for Forest Roads Constructed Using Various Technologies from Mechanically and Chemically Stabilised Aggregate

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Forest roads are essential for adequate forest management and environmental protection. They enable tourism and recreation activity, while at the same time playing a very important role in fire protection. When open to the local traffic, they significantly supplement the public traffic networks. Costs of constructing permanent roads in forested areas are considerable, because they need to have adequate bearing capacity. Forest roads are predominantly constructed using natural or anthropogenic aggregate stabilised mechanically and chemically. A tangible parameter verifying the proper construction of road structure is provided by its bearing capacity, i.e. the capacity of the pavement to carry loads generated by traffic without excessive strains hindering normal use of the pavement or reducing its durability. Some forest road networks are also constructed as temporary roads composed of cheaper aggregates. It seems reasonable to assume different bearing capacity standards for such roads than for permanent roads.

The aim of the studies presented in this paper was to develop bearing capacity standards for forest roads constructed using various technologies. The adopted research hypothesis assumes that each of the analysed technologies is characterised by a different bearing capacity required during road construction inspections. An example of such a structure may be provided by the so-called geotextile mattress and crushed stone constructed on wetland soils. When developing the standards, the analyses included the predicted traffic intensity, assumed operation time before rehabilitation is required, soil conditions and the type of construction material.

Bearing capacity of the testing road sections was assessed based on values of strain moduli calculated from the static plate load tests (VSS). As a result, bearing capacity standards were obtained for structures constructed using aggregates and chemical stabilisers as well as geotextiles potentially facilitating reduction of the layer thickness without deterioration of road durability.

Workability and Well-Being at Work Among Cut-To-Length Forest Machine Operators

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This study assessed the situation of Finnish cut-to-length (CTL) machine operators’ work well-being with workability index (WAI), investigated CTL machine operators’ lifestyle habits, and collected operators’ good practices to maintain and promote well-being and vitality at work. A questionnaire was conducted in electronic form, including questions concerning background information, work environment, work organisation, well-being at work and free time, and workability index. Mean WAI among respondents was 42.2 points (max. 49) falling into the rank »good«, while the current workability compared with the lifetime best was 8.2 (range 0–10). WAI was strongly impacted by age (p<0.000), the score declined during ageing, and standard deviation grew. The results were in line with previous WAI studies. Statistic differences were found between youngest age group (age≤25) versus all others. Compared to other studies and occupational groups, CTL machine operators’ WAI was average. Operators revered independent nature of work and forest as a working environment, thus promoting and maintaining well-being at work. Furthermore, breaks during work shift, with or without physical exercise, was recognised to ensure and retain vitality and concentration at work.

Machine Rate Estimates and Equipment Utilization – A Modified Approach

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As mechanization increases, the percentage of the total cost of the logging operation due to equipment purchase and operation increases. This makes assumptions about machine life, machine maintenance costs, and fuel consumption more critical in understanding the costs of logging operations. For many years machine rate calculations have followed a fixed format based on the concept of scheduled and productive machine hours. When equipment utilization is less than 100%, the traditional machine rate calculation assumes that the machine continues to depreciate and machine wear occurs during the non-productive time at the same rate as during the productive time. This can lead to overestimates of the hourly cost of machine operation by effectively shortening the machine lifetime productive hours as the utilization decreases. The use of inflated machine rates can distort comparisons of logging systems, logging strategies, equipment replacement strategies, and perhaps the viability of a logging operation. We propose adjusting the life of the machine to account for non-productive time: machine life in years should be increased with a decrease in machine utilization, while cumulative machine life in hours remains the same. Once the life has been adjusted, the traditional machine rate calculation procedure can be carried out as is normally done. We provided an example that shows the traditional method at 50% utilization yielded a machine rate per productive hour nearly 30% higher than our modified method. Our sample analysis showed the traditional method consistently provided overestimates for any utilization rate less than 100%, with lower utilization rates yielding progressively increasing overestimates. We believe that our modified approach yields more accurate estimates of machine costs that would contribute to an improved understanding of the machine costs of forest operations.

The Effect of Yarding Technique on Yarding Productivity and Cost: Conventional Single-Hitch Suspension vs. Horizontal Double-Hitch Suspension

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Cable yarding is a well establish technology for the extraction of timber in steep terrain. However, it is encumbered with relatively low productivity and high costs, and as such this technology needs to adapt and progress to remain viable. The development of biomass as a valuable byproduct, and the availability of processors to support yarder operations, lend themselves to increasing the level of whole-tree extraction. Double-hitch carriages have been developed to allow for full suspension of whole-tree and tree-length material. This study compared a standard single-hitch to a double-hitch carriage under controlled conditions, namely in the same location using the same yarder with downhill extraction. As expected, the double-hitch carriage took longer to load up (+14%), but was able to achieve similar productivity (10–11 m3 per productive machine hour) through increased inhaul speed (+15%). The importance of this study is that it demonstrates both the physical and economic feasibility of moving to whole-tree extraction using the double-hitch type carriage for longer corridors, for settings with limited deflection, or areas with lower tolerance for soil disturbance.

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Web of Science Impact factor (2019): 2.500
Five-years impact factor: 2.077

Quartile: Q1 - Forestry

Subject area

Agricultural and Biological Sciences

Category/Quartile

Forestry/Q1