Väätäinen Kari, MSc.

Logistics of roundwood and biomass comprise a high number of operations, machinery, storage sites and transportable roundwood and biomass assortments. Moreover, complex and highly varying operational environment through the year poses logistics challenges incurring additional costs. An extensive review of studies was conducted in Sweden and Finland concerning roundwood and biomass logistics, starting from roadside landings and ending with delivery to a mill or a conversion facility. The main aim of the review was to describe trends in roundwood and biomass logistics since the start of the century. Papers were classified to categories of truck transports and roads, terminals, multimodal transports, storage and supply chain logistics. Slightly over 50% of reviewed articles were constrained to biomass only, 31% to roundwood only and 14% to both. Rapid technology development, amendments concerning road transports, increasing environmental concerns and forestry sector’s push to decrease the logistics costs can be seen as the biggest drivers for the reviewed studies and their study objectives. These aspects will also drive and increase the demand for research and development in roundwood and biomass logistics in the future.

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.

Stump harvesting for energy has decreased in Finland, and many heat and power plants no longer accept stumps in their fuel portfolio due to fuel quality problems. However Finland is a forested country, and land clearing stumps need to be extracted, e.g. in infrastructure construction projects. If stumps cannot be used for energy production, they are dumped in landfills, where they start to decay and release CO2 into the atmosphere. One option to avoid CO2 emissions would be the burying of stumps underground so that the decaying process of wood would be inhibited in anaerobic conditions. The aim of this study was to define the carbon sequestration potential of stump burying logistics and calculate their CO2-eq emissions to compare them with the emissions of decaying stumps in piles. The analysis was performed as a spreadsheet-based system analysis at a worksite level as a function of time and size of extracted stumps. As a result of the analysis, the emission effiency of the logistics chain based on stumps stored below the ground was good. The net carbon stock varied between 743.7 and 775.0 kg CO2-eq/m3 as a function of stump diameter, when the emissions of the stump burying logistics chain were 49.0 and 17.7 kg CO2-eq/m3 respectively. In the case of a Finnish municipality with an annual accumulation of 1000 m3 of land clearing stumps, the carbon sequestration potential of stumps buried underground is equivalent to the emissions of between 280,000 and 290,000 liters of diesel fuel consumption, depending on the diameter of the extracted stumps and the diesel fuel emission factors for different engine and diesel fuel types.

Fuel consumption is one of the key parameters in mechanised forest operations, particularly on lower bearing capacity soils, as wheel chains or bogie tracks can have a strong effect on it. This study aims to analyse the fuel consumption of several individual wheeled cut-to-length forwarder set-ups with different types of bogie tracks on peatland using automatic recording of data bus information. Two types of forwarders, 8-wheeled and 10-wheeled, and three types of tracks were tested on peatland in Eastern Finland. A mixed-model approach is the basis to study the fuel consumption as a function of the soil bearing capacity, the number of passes of the machine on the same soil, the section (curve or straight) and other variables related to the machine performance and set-up, for a total of N=27,928 fuel observations on three machines in 33 plots (trail segments). The model results in an R2=0.78; the number of passes increases the fuel consumption significantly, while the soil bearing capacity did not affect the fuel consumption. There are, however, important differences between the machines performance, which are addressed in the model. By contributing to the knowledge on the connection between operational conditions and fuel consumption, the study can contribute to the aim towards a sustainable forest operation through minimizing negative environmental impacts and providing the necessary tools for further research efforts.