This article presents the results of laboratory examinations concerning the effects of soil bulk density on the growth of sessile oak Quercus petraea Liebl. seedlings. The soil for the study was collected from a nursery plot and then compacted into PCV pots in eight different bulk density levels ranging from 0.81 to 1.32 g cm⁻³. Oak seedlings were cultivated in controlled conditions for 76 days after sowing. The growth and mass parameters of particular seedlings together with the parameters of the assimilation apparatus and roots were measured, taking into account the share of various diameter roots in the root system. For the purpose of the experiment, 120 acorns were sowed, of which 73 seedlings were cultured. An analysis of the growth of the sessile oak seedlings revealed that a change in soil density significantly affected root system development, total height of seedlings and dry mass. It was observed that the dry mass of the root system as well as the area and length of the roots decreased with an increase in soil density. Root system reduction was noted, the size of which determines the proper development of the tree and ensures its stability. Besides a decrease in the root system, an increase in soil compaction also resulted in a reduction in the number of roots of a specified diameter. The first to be affected were the smallest roots, i.e., those with diameters up to 0.2 mm, which are responsible for the uptake of mineral components. It was confirmed that even a slight increase in soil compaction might negatively result in the growth of young seedlings, impeding root system development.

Cultivation of seedlings in trays requires the use of specifically developed substrates. This study presents the results of the analyses of selected physical and mechanical parameters of a peat–perlite substrate, in which seedlings of the Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst), European beech (Fagus sylvatica L.), and pedunculate oak (Quercus robur L.) were grown during a production season. For each species, the substrate parameters changed throughout the production season, substrate dry weight decreased, whereas its compactness increased with time. Independent of the species, the bulk density and total porosity of the substrate changed or deviated from the optimum range, although the values of porosity were close to maximum and those of density were close to the minimum. In certain periods in the V265 trays with beech and oak seedlings, the substrate was characterized by very low water capacity and excessive air capacity. Compactness measured with a cone penetrometer showed, that this parameter might be used for monitoring the substrate properties.

Ground contact pressures exerted by elements of the machine chassis on the ground in the forest are associated with the machine impact on the soil during its operation. In the case of a crawler system, determining the ground contact pressure appears simple, which is not entirely true. The aim of the study was to analyze the loads on the ground (forest soil) exerted by the MHT 8002HV crawler harvester chassis. The measurements were made in Forest School Enterprise in Kostelec nad Černými Lesy, Central Bohemia Region in the Czech Republic, on brown soil made of clay on stony formations, fresh mixed mountain forest (FMMF), with the use of a hydraulic scale when extending the harvester crane forward along and perpendicular to the longitudinal axis of the machine. The calculations were carried out with a simulated load of the crane on the tree in question, assuming that the impact on the ground of the crawler system is heterogeneous and that the point impact comes from the crawler support wheels. As it was shown, the average ground contact pressures under the crawler track of the analyzed harvester generally do not exceed 70 kPa. The crane extension with a simulated load, which would have caused the crawler track to act on the ground with an average pressure exceeding 70 kPa, was limited by machine stability. On the other hand, high ground contact pressures may occur under a more loaded section of the crawler track if the active length of the crawler track is shortened. As it was shown in the case of a weak track tension, the course of ground contact pressures exerted on the soil deviates from the assumed usually homogeneous impact over the entire length of the crawler.

The quality of container-grown seedlings is influenced by the air and water properties of the substrate. These properties are closely tied to the amount and frequency of water supplied through sprinkler systems in nurseries, as well as the density of the substrate in the container cells. Throughout the entire growing season, this study examined how various parameters of Scots pine, Norway spruce, European beech, and pedunculate oak seedlings cultivated in HIKO V120SS and V265 containers were affected by two factors. Firstly, the study analyzed the impact of increased substrate density when filling the containers. Secondly, it explored the precise dosing of water applied by the sprinkler system, which was determined based on substrate sensors and meteorological conditions surrounding the seedlings. The results revealed that increased substrate compaction led to a long-term reduction in air capacity and an increase in water capacity within pine, spruce, and beech containers. However, oak seedlings were not affected by the increased substrate density. Additionally, the higher density of the compacted substrate positively influenced the growth parameters of pine seedlings but did not affect the other species. As a result, the current substrate compaction level used in the nursery where the measurements were taken appears to be optimal for spruce, beech, and oak seedlings. Furthermore, precise control over the amount of water applied during irrigation allowed for a reduction in water consumption by about 8%. This control also resulted in improved seedling sturdiness quotient and a more developed root system in the case of pine seedlings. However, no significant differences were observed for the other species.

The aim of the study was to characterize repetitive cycles of harvester operation. The study was conducted in thinning, mature and post-disaster pine stands. The sequences of the activities characteristic of harvester operation were described as time series. In order to detect the cyclic variable structure of the analysed time series, the methodology of the single spectrum Fourier analysis was applied. In standard stands, post-disaster late-thinning stands and mature stands, the existence of stable operational cycles with the length of three activities was discovered while in post-disaster mature stands additional five-activity operational phases were noted. Described in this way, the lengths of the operational cycles of harvesters working in post-disaster areas were higher by about 55% and 30% respectively, as compared to standard thinning and mature stands.

For many years, scientists have been searching for nondestructive methods for the measurement of plant root system parameters. The measurement of electrical capacitance (EC) across the root has been proposed as one such nondestructive method. This article presents a study on the determination of relationships between EC measurement and the shape and size of the electrodes immersed in medium that are used for measurement. Measurement of EC and the parameters characterizing root systems of 1-year-old seedlings of the common beech Fagus sylvatica L. was conducted under laboratory conditions. The measurements of EC were performed between seedling root systems and two different electrodes in the form of a cylinder or a rectangular plate. Statistically significant correlations were found between the capacitance and root system parameters in both the variants; however, the correlations were higher in the case of the flat rectangular plate. Correlation coefficient (r) between EC and total root length was 0.688 for cylindrical electrode and 0.802 for rectangular plate, for total root area 0.641 and 0.818, and for dry weight of root system 0.502 and 0.747. The best-fitted linear regression relationships between the EC and the measured parameters were characterized by low determination coefficients in variants with cylindrical electrodes, and higher with flat rectangular plate electrodes. The results indicated that a two-dielectric media concept is a better model than Dalton’s model when attempting to interpret the behavior of root and soil capacitance. The different electrodes probably allow root capacitance measurements to be interpreted from different aspects. However, this hypothesis requires further verification.