The study presents information on changes in the demand for wood on the primary wood market in the years 1997-2005. Results of analyses are presented together with an assessment of the relationship between changes in demand and changes in prices for wood assortments. The paper also discusses results of investigations concerning an analysis of sales of pine round wood, taking into consideration the analysis of price elasticity of demand. The study was also an attempt to present current problems connected with timber market.

The paper presents the analysis of the breast height diameter, height and biosocial structure of 39-year old European silver fir introduced artificially and growing, until winter 1991/92, in different conditions created by three different fellings carried out in hornbeam-oak old forest growing on a fresh mixed forest site type. Following the removal of the old forest in winter 1986/87 on the plot with the group clear cutting and in winter 1991/92 on the plot with the shelter wood cutting, the fir is growing in all three variants in open area. The inventory carried out in 2005 revealed that, in each case, the best experimental results were obtained by the stand on the surface with the group clear cutting (3-Rg). The stands from surfaces with the clear cutting (1-Rz) and shelter wood cutting (2-Rcz) show worse results which also differ from each other. From the point of view of mean breast height diameter and height, a better situation was observed on the 1-Rz, while from the point of view of the number of trees, mean Kraft class and productivity – on surface 2-Rcz.

The paper presents the results of investigations carried out on the experimental plot which was established in 1914 by professor Busse from Tharandt. The objective of the experiment was to determine the age of maternal trees on the growth and development of progeny stands. The study describes the course of investigations as well as the results obtained during the consecutive periods. The presented results refer to seven provenances of Scots pine derived from the stands of the following forest districts: Zielonka, Bolewice and Brójce. The experimental surface was established on the Trzciel Forest District in Poland. Busse’s principal methodological assumption was to employ in his experiment seeds of trees of different age (16 to 170 years old). The presented paper discussed the results obtained during the period from 1965 to 2006. Two provenance groups were identified on the basis of statistical differences and similarities: older maternal stands – more favourable characters of progeny growth and development: IV, V, VI (101-170 years of age) and younger maternal stands – less favourable characters of progeny growth and development: I, IIb, III (16-80 years of age).

The aim of the study was to investigate the energy expenditure and static load of a worker during harvesting wood in pine stand clear cuttings. The performed experiments involved two technological treatments in which timber was harvested either in the form of large-size logs or medium-size rollers and blocks. The above variants differed with regard to the spatial order on the felling area (organised and unorganised felling). The energy expenditure was determined on the basis of measurements of lung ventilation, while static load – using the OWAS method. The obtained net unit energy expenditures were similar in both variants and reached 30 kJ/min and exceeded the limiting value of the so-called durable efficiency of the organism. With regard to the static loading, in each variant, the worker was found to be loaded moderately.

Light conditions exert direct effects on metabolism, growth and development of plants, including their ability to defend against pests. In this study, we explored the impact of light conditions on response of six understory shrub species (Sambucus nigra, Prunus serotina, Prunus padus, Cornus sanguinea, Frangula alnus and Corylus avellana) to grazing by herbivore insects. Shrub species differed significantly in the level of foliar perforation by insects. Except for C. avellana, leaves of plants exposed to full sun were less affected by leaf-chewing insects than leaves from plants grown in low light. It is likely that shade-grown plants have higher host quality due to their lower content of secondary metabolites (soluble phenols and condensed tannins) and higher content of nonstructural carbohydrates and nitrogen. However, there were no significant relationships between interspecific susceptibility to grazing and leaf chemistry, indicating that other factors such as combined effect of host defense and herbivore abundance may be responsible for observed differences in foliar perforation.