The study focuses on the fauna and its aim was to prepare a register of mesostigmatid mites reported from the Tatra National Park. The register was prepared on the basis of literature and the author’s own research conducted in the park. The study describes 115 mite species from the order Mesostigmata reported from the Tatra National Park. The most numerous were families Parasitidae (27 species) and Zerconidae (14).

The precision of insect number determination in forest litter using a method, in which the sample element comprised 10 plots of 0.5 m² each, was compared with that of the method, in which the sample element consisted of one plot of 5 m². Investigations were conducted in four pine stands aged 59-80 years. The number of cocoons of Diprioninae found in the litter was counted. It was found that the precision of the compared methods was very low at a slight density of cocoons and it increased with an increase in their density. It would not be justified to say that the two compared methods of measurement for sawfly cocoon density differ in terms of their precision.

Vibration levels were measured while cross-cutting pine wood logs. In the experiment five chisel type cutting chains, with a 0.325” pitch were used. The chains differed in the top-plate filing angle which had the following values: 20º, 25º, 30º, 35º and 40º. The cross-cutting was performed by a chain saw operator. The measurements were carried out on the front and rear handles in the x, y and z axes. There were 18 measurements for each top-plate filing angle on each of the handles. The Robotron M1300 meter was used. Considerably higher vibration levels were observed on the rear handle. The effect of the top-plate filing angle on the mechanical vibrations was statistically significant. The correlation between the angle and the vibration value showed a weak relation, but it was statistically significant in those cases in which it appeared.

The study was undertaken to show the possibility of wood swelling pressure determination on the basis of the time course of its mechano-sorptive creep induced by bending stress of different values and simultaneous moistening of the compressed zone. The creep was induced in the conditions of three-point bending of beech wood (Fagus sylvatica L.). The bending pressure applied in the radial direction was of the magnitude of 0.05, 0.1 and 0.15 of the mean destroying stress determined for the samples of moisture content of about 7%. Immediately after application of loading the samples were subjected to asymmetric moistening in the zone of compressive stress. For the sake of comparison also the free sorptive deformation of analogous samples was observed. On the basis of the linear relations between the deformation (recorded at specific time intervals during the process of mechano-sorptive creep) and the bending stress applied, it was possible to determine the values of the stress at which the samples would remain in the non-deformed state despite their asymmetric moistening. The maximum swelling pressure determined in this way is by about 50% greater than that found in the direct way.

The investigations were carried out on the common sea buckthorn (Hippohaë rhamnoides L.) growing in the coastal areas of the Baltic Sea. The performed analyses comprised the determination of the basic chemical composition and selected heavy metals. For comparative purposes, investigations were also conducted on wood of the common sea buckthorn growing in urban conditions, namely in the city of Poznań. On the basis of the performed experiments it was found that the content of cellulose in the examined material ranged from 33.6 to 39.3% with the highest values determined in the wood of bushes growing in urban conditions. In addition, considerable differences were also observed in the lignin content in the compared samples, whereas the concentration of pentosans remained at the level of 18% irrespective of the place of sample collection. Concentrations of the examined heavy metals did not exceed levels dangerous for the growth and development of the examined bushes.