Marina Chavenetidou

Charcoal production sites serve as palaeoarchives and contain wood charcoal, which can be identified taxonomically and be utilized to obtain information and reconstruct the past vegetation, based on the occurrence of woody taxa. In the present research, the study material was collected from the Black Forest south of Freiburg (Germany), in the Schauinsland region. Charcoal samples were gathered from the surface as well as from various depths in the soil (30 cm, 60 cm and 90 cm). The main identified taxa were Abies and Fagus, almost at the same percentage of constitution, providing evidence for their growth in the area and their selection for charcoal production. The number of growth rings and samples dimensions were measured, in order to gather information of the climatic conditions and the productivity of those past time periods.

The aim of this study was to evaluate the suitability of eight softwood species most commonly used by Greek timber industries, including furniture manufacturers and companies producing roundwood, sawn timber, and plywood. The analysis was based on integrated Multi-Criteria Decision Analysis (MCDA), using a combined approach of the PROMETHEE method and the Analytical Hierarchy Process (AHP), taking into consideration some important criteria that affect timber quality. According to the PROMETHEE complete ranking, Aleppo pine (Pinus halepensis Mill.) achieved the best performance under the selected criteria among the examined softwood species, underlying the importance of Aleppo pine to the Greek timber industry. Our findings could be highly beneficial to the wood industry, promoting the recovery and advancement of the forest sector in general, taking into account that sustainable wood supply is lower than the total biomass available in Europe. Policymakers should prioritize the selection of conifer tree species that can strengthen Greece’s forestry sector, promote sustainable management practices, and increase the economic value derived from the country’s diverse forest resources.

Anatomical features of wood cells and their size variations are key elements of wood identification. This research focuses on the microscopic differentiation between four Quercus species, two Red Oaks (Q. cerris and Q. rubra) and two White Oaks (Q. alba and Q. petraea). More specifically, it studies the variation of vessels width in earlywood and latewood. The results showed that in earlywood, Q. rubra exhibited the widest vessels (332.27 ± 65.21 μm), followed by Q. cerris (300.27 ± 57.62 μm), Q. petraea (286.09 ± 58.83 μm), and Q. alba (200.82 ± 43.50 μm), in descending order of size. Conversely, in latewood, Q. cerris displayed the largest vessels (83.89 ± 20.31 μm), with Q. rubra following closely (74.05 ± 20.31 μm). Q. petraea (35.34 ± 6.11 μm) and Q. alba (26.70 μm) maintained their order, appearing a consistent pattern between the wood growth phases. The variability in vessel dimensions was also supported by statistical differences among most species combinations both in earlywood and latewood. The investigation of certain vessel traits may serve as a valuable component of studies related to wood properties and species adaptability in the context of climate change.

Wood constitutes a unique and valuable material that has been used from ancient times until nowadays in a wide variety of applications, in which the surface quality of wood often constitutes a critical factor. In this study, the influence of different wood areas and therefore, of different anatomical characteristic areas of chestnut wood (Castanea sativa Mill.) on the surface quality, was thoroughly studied, in terms of surface roughness. Five different chestnut tree trunks were harvested, from which five different disks were obtained corresponding to five different trunk heights. Surface roughness was measured on these disks on the transverse, radial, and tangential planes, on the areas of sapwood and heartwood, measuring the roughness in each point both vertically and in parallel to the wood grain. The results revealed that the examined roughness indexes (Ra, Rz, Rq) follow a parallel path to one another. In the case of all surfaces (transverse, radial, tangential) of the disks examined, when the measurement was implemented perpendicularly to the wood grain, a significantly higher roughness was recorded, compared to the wood grain measurements being implemented in parallel with the wood grain. Significant differences between heartwood and sapwood roughness were not demonstrated, although sapwood often appeared to exhibit a higher surface roughness than heartwood sites. Among the roughness values of the three different surfaces, the highest roughness in the vertical-to-wood-grain measurements was recorded by tangential surfaces, with slightly lower values on the transverse surfaces and the lowest roughness on radial surfaces. Meanwhile, for the measurements in parallel with the wood grain, the transverse surfaces presented significantly higher roughness values compared to the tangential and radial surfaces. Significant roughness differences were not detected among the surfaces at different trunk heights. Although, significant differences in roughness were recorded among different trees, it was observed that all the studied trees align with the identified and described within-tree trends.

Examination of the technical and economic dimensions of skidding operations is imperative for sustainable forest management, offering invaluable insights crucial for the formulation of sustainable forestry strategies. In many countries, the shift from modified agricultural machinery to purpose-built forest machinery has become apparent in forest operations. However, this transition often accompanies a reduction in logging crew size, raising new questions about productivity, costs, and ergonomics of the introduced harvesting systems. This study investigates two skidding systems utilizing the cable-grapple skidder Welte 115/5L, differing in work team size: one with one skidder operator and two chainsaw operators (WT3) and the other with one skidder operator and one chainsaw operator (WT2). Conducted in natural European beech forests in southern Bulgaria, the research focused on the group shelterwood system within the Natura 2000 network. Both WT3 and WT2 exhibited net skidding productivity of 9.96 m³ PMH⁻¹ over a mean skidding distance of 300 m and a mean winching distance of 20 m, outperforming conventional systems in the area. Despite this, there were notable differences in gross skidding productivity (8.64 m³ SMH⁻¹ for WT3 vs. 7.30 m³ SMH⁻¹ for WT2), affecting skidding cost (EUR 5.41 m⁻³ for WT3 vs. EUR 6.62 m⁻³ for WT2) and unit production cost (EUR 9.33 m⁻³ vs. EUR 11.53 m⁻³). This study highlights that the cable-grapple skidder can be effectively employed by smaller teams, providing higher productivity, lower unit cost, and increased flexibility during piling, primarily due to the presence of the knuckle-boom loader. While WT2 experienced more delays and production pressure, the findings suggest that WT3 represents a balanced option for small logging crews, ensuring sustainable forest operations in the face of workforce challenges.