The wood chips (product of chipping) can be assigned for production of particle and fibre boards. The object of the performed investigations was to determine fractions of industrial wood chips. The chips were harvested with chippers of various kinds. The determination of chips fractions was based on 5 fraction classes. In all the samples, fraction 10-35 mm was the most numerously represented. For all the experimental surfaces no statistical substantial differences between < 2 mm fraction and > 50 mm fraction were found. The results of fractions of industrial wood chips dimensions were up to Polish standards of industrial wood chips dimensions.

The study was carried out in 39- and 43-year-old stands of noble fir (Abies procera Rehder) grown in the Rogów Arboretum of the Warsaw University of Life Sciences (Poland). The main objectives of our study were (1) to estimate stem volume over bark of noble fir grown out of its natural range, (2) to develop suitable allometric equations for estimating aboveground woody biomass components and (3) to estimate aboveground woody biomass components using site-specific allometric equations and to compare them with biomass estimated using allometric equations developed in stands grown within natural range of noble fir. The study showed that the mean DBH of trees was 20.14 cm in the younger stand and 22.25 cm in the older stand. The basal area of the 39-year-old stand was 49.01 m²·ha^-1 and 43-year-old stand was 47.53 m²·ha^-1. Based on the developed equation stem volume over bark was 374.87 m³ ha^-1 and 356.24 m³·ha^-1 in the 39- and 43-year-old stands, respectively. Based on the developed site-specific allometric equations total aboveground woody biomass in the 39-year-old stand was 189 Mg·ha^-1 whereas in the 43-year-old stand it was 184 Mg·ha^-1. Branch biomass in both stands equaled 19.9% of total aboveground wood biomass. Total aboveground woody biomass, estimated by allometric equations published by Ter-Mikaelian and Korzukhin [1997], equaled 233 Mg·ha^-1 and 228 Mg·ha^-1 in the 39- and 43-year-old stands, respectively. This means that the aboveground woody biomass is overestimated by ca. 23% in comparison with biomass estimated by our site-specific allometric equation. Generally, the existing equations published by Ter-Mikaelian and Korzukhin [1997] overestimated total aboveground woody biomass and stem biomass, while branch biomass was underestimated across all tree sizes compared to directly obtained biomass data.

The paper presents an analysis of energy consumption values for two machine energy wood harvesting technologies. Both technologies were used to produce woody fuels from logging residues, one focused on chipping and the other on bundling logging residues. The energy analysis comprised the built-in energy in the machines used, the energy contents of the fuels used and physical loads of machine operators. The energy contained in the fuels used by the machines dominated and its share in the total consumption reached 75%. The analysis of energy consumed in different technological operations showed, that the hauling of chips and bundles (50 km) were most energy consuming, and the energy consumption value reached 100 MJ/m³. Both energy wood harvesting technologies, in which wood chips as well as bundles were produced, showed similar energy consumption values, which amounted to about 196 MJ per 1 m³ of woody fuels.

The investigations were conducted on 21 BP Oregon cutting chains, with five top-plate filing angle values: 20°, 25°, 30°, 35° and 40°. The chain saw was a 254 Husqvarna model with an Oregon 15” bar. The vibration measurements were conducted while cross-cutting pine logs, and they were performed according to the PN-91/N-01352 [1991] standard. For each of the angles tested 36 measurements were carried out (18 measurements on the front handle and 18 on the rear one). The investigations proved statistically significant differences in vibration levels between different top-plate filing angle values. Apart from that, significant differences were found between vibration levels on different handles and in different measurement axes (x, y, z). The lowest vibration levels were found with chains with extreme top-plate filing angles (20° and 40°). Statistically significant relations between top-plate filing angles and vibrations levels were also found for the front handle in the x and z axes and for the rear handle in the x and y axes.

The objective of this paper was to test in practical conditions possibilities of the application of GIS to design multi-variant educational pathways in the forest. An attempt was also made to develop a system of management of spatial information which makes it possible to design different alternatives of pathways in a specific forest complex. Nearly every fragment of the forest can be used to create educational paths. Usually, areas chaacterised by a considerable variability, situated in regions easily accessible for people are selected for such purposes. In the case of a strongly diverse area, the creation of multivariant paths may be an ideal solution by providing different routes for persons of different ages and levels of education. There can also be theme alternatives presenting different problems or variants intended for selected ways of movement. GIS is very useful when designing many variants of educational pathways in one area. This system facilitates data collection at the phase of field inventory and allows designing many different alternative routes, as well as managing them in the course of their utilization.