This research deals with the problem of the accessibility of urban forests and parks for people with disabilities in wheelchairs. Through an analysis of spatial data, trails were categorized on the basis of the measurements of the independent movements of eight subjects on six trails. The critical longitudinal slopes were determined for independent movement in wheelchairs, complex independent movement with certain risk, and categories of trails that are not suitable for wheelchair movement. The results indicate that a slope of 5.50% was the tipping point, after which all respondents experienced some uncertainty. In addition, a gradient of more than 9.01% was almost impassable for people in wheelchairs, with respect to the gravel trails examined in this study. Modern measurement technology was used in the field, including the mobile apps GAIA GPS and GNSS GPS, and a total (geodetic) station; the subjects’ heart rates were measured using a Garmin Fenix 6 Pro watch. In addition, people with disabilities were included in the implementation of the research through the Croatian Association of Paraplegics and Tetraplegics (HUPT). The results indicate the zones/trails that disabled people in wheelchairs can pass independently, the zones that can be accessed with a certain risk, and those that are not accessible, all according to the defined longitudinal slope zones using measurements of the movement of people in a wheelchair, their heart rate loads, and personal communication with the subjects regarding the insecurity they felt.

During forest harvesting operations, exhaust emissions from forest vehicles are released at different levels depending on several variables. This pollution released into the atmosphere is considered one of the main anthropogenic factors that negatively affect forest ecosystems. In this study, we analyzed exhaust emissions from a skidder diesel engine during various engine loads. Measurements were done on an ECOTRAC 140 V skidder with the water-cooling diesel engine and a built-in catalyst with an SCR system. The composition and amount of exhaust gases (CO, CO₂, O₂, NO_x,) at different loads of the diesel engine of the skidder and engine temperature were measured using a MAHA MET 6.3 measuring device. The amount of exhaust gases was analyzed in relation to the engine speeds, engine temperatures, and the European emission standards for engines used in nonroad mobile machinery (NRMM). Influences of catalyst systems and recommendations for more environmentally friendly forest harvesting practices are addressed. With the engine unloaded, the amount of CO₂ increased when engine speed was increased, while other amounts of exhaust gas decreased. During the cold start, the concentrations of hydrocarbons and nitrogen compounds were high. The composition of the exhaust gas was affected by the exhaust reduction system installed in the tractor and the amount of the exhaust gas was dependent on the engine load. The skidder engine met the requirements of the exhaust gas standards EPA/COM IIIB Tier 4 (I) under which it is declared. With a load engine during winch operation (2300 rpm), NO_x amounts mostly exceed the limit values of the standard. Exhaust emissions can be reduced at various operating levels by utilizing the most environmentally friendly technologies and following the correct procedures, such as warming the engine up to operating temperature prior to operation and operating in the most favorable mode with optimal speed. The regular reduction of exhaust limit values to newer stages of the standard therefore leads to the continuous development of engines and forest vehicles in general.

Compiling the research on forestry ergonomics, which is still a marginal field in terms of the sheer volume of published forestry-related articles, gives a good foundation and guidance for future research and publishing. This review aims to compile, classify, and analyze forestry ergonomics publications in JIF (Journal Impact Factor) journals regarding their spatial and temporal distribution, observed operations, machines and tools, and risk factors. A reference period from 2014 to 2023 was observed in this study. The Web of Science Core Collection database was used to filter publications in the field of forestry and ergonomics. A total number of 102 articles were selected. After selection, data regarding publishing year, journal name, main field, country of origin, forest operation, machine/tool, and risk factor were noted. The number of articles is ever-increasing with the last four years having above average numbers of articles. Countries from Europe and South America (Brazil) have the most publications. Most of the journals are ranked in the top 50%. Harvesting, wood extraction, and pre-harvesting operations have the highest number of records. Chainsaw, skidder, and pre-harvesting tools are the most observed means of work. The risk factors with the highest percentage of records are workload (23%), noise (20%), vibration (20%), postural load (16%), and MSD (Musculoskeletal Disorder) occurrence (7%).

The increasing importance of utilizing new technologies, such as GNSS (Global navigation satellite system) devices, total stations, drones, scanners, etc., in forestry has become evident with the development of these tools. Combined with precise GNSS devices, UAVs represent an efficient tool that facilitates field measurements and reduces time spent in the field while also providing highly accurate data. To accurately determine the application of spatial data for calculating the longitudinal slope of forest/logging roads in a research project, measurements based on UAVs were conducted and compared with GNSS data. GNSS data were considered the reference values for the studied area, assuming that satellite positions and internet signals were good. An accurate longitudinal slope was necessary to define fuel consumption on forest/logging roads and slopes throughout the project and to verify the calculation method that could be applied for such or similar terrain conditions and overgrowth. The main goal of this research phase was not to study fuel consumption but to obtain an accurate longitudinal profile of forest/skid roads on rocky terrain that is not overgrown or poorly grown. The study put forth two hypotheses, one of which was ultimately confirmed, while the other was refuted. The results show no significant differences when comparing the absolute elevation of the points in the profiles for defining the longitudinal slope of the road using the program for designing forest/skid roads. While applying such a method of data collection to create the main projects for the (re)construction of forest/skid roads, there are significant deviations in earthwork masses. There was a difference of over 22.64% in one of the types of earthwork excavation on the designed forest road, so the method implemented in the research does not give sufficiently accurate results.

SEEFOR - South-East European Forestry

The paper deals with the analysis of the fuel consumption of skidders during timber extraction from thinning of even-aged beech forest on mountain terrain. Fuel consumption research was conducted on the Ecotrac 140V cable skidder over 8 working days at the same worksite during real timber extraction work. The worksite was organized so that the empty skidder traveled uphill, and when loaded, it moved downhill. The skidder was equipped with measuring devices for collecting data from sensors, the motor, and data transfer. The key parameters measured include total fuel consumption (mL) and skidder GPS position, while slopes of skid trails and load volumes were measured directly on terrain. Fuel consumption (L, L/m³) was determined per work cycle and work cycle elements. The highest fuel consumption occurred while driving the unloaded skidder, accounting for 38% of the total. This is primarily because fuel usage during skidder movement is significantly affected by factors such as skidding distance, slope, and skid trail conditions, especially since the unloaded skidder was moving uphill. Guidelines for better and more efficient organization of work and reduction in fuel costs are presented, and the suitability of the skidder and harvesting system are considered based on the results of fuel consumption.