Bilberry in mountain areas was characterized by a higher average intensity of fructification and greater height of dwarf shrubs as compared with bilberry in lowlands; at the same time, the weight of a single berry and its diameter were smaller. In the mountains, dwarf shrubs occurred in bigger formations whose density was larger especially in open areas (outside forest stands). The bilberry base in lowland and mountain areas was analysed against the background of a site type of forest and forest density index.

The experiment was established in 1979. The aim of this study is to determine the most suitable spacing for plantations of common birch, the Polish larch, Norway spruce and Douglas fir by the examination of the dependence between the spacing and the growth of trees. After 22 years clear influence of the spacing on the biometric characteristics (diameter at breast height, diameter at the height 0.3, the height end volume) was stated in case of the tested fast-growing tree species.

A field experiment was conducted in 1996-1997 and it aimed at assessment of different methods of soil preparation in Scots pine natural regeneration originated following the shelterwood cutting system. The experiment was established in the Puszcza Solska Forest. Soil preparation was made with forest plough (LPz-75), disc harrow (BT), and disc plough (PTL-2). It turned out that in the first year the best results were observed in the forest plough (LPz-75) treatment with 11.8 N/m2 seedlings at the beginning of the vegetation season and 4.6 N/m2 at the end of thereof. The second year number of seedlings was maintained at a similar level, but seedlings from the disc harrow (BT) variant were higher and much more vital than those in other variants. According to the present experiment, variants with forest plough and disc harrow are to be recommended for practical use.

The article deals with the change of crown defoliation of Scots pine trees (Pinus sylvestris L.) in the Siemianice Experimental Forest Division on the basis of observations conducted in 1996 and 1999. The discussion comprises the distribution of the level of defoliation, share of degrees of opening according to European classification, defoliation indices and means of tree crown defoliations of 1-3 and 4-5 Kraft classes. The crown state of pine trees in the Siemianice Experimental Forest Division improved considerably during three years. This process is more visible in the case of trees of 1-3 Kraft class than in 1-5 Kraft class, which testifies to a greater vitality of trees from the primary stand. Mean defoliation and defoliation indices of trees of the primary stand and of the entire stand are clearly connected with age classes. Changes in the condition of crowns of pine trees recorded in the examined forest division depict favourable processes in pine stands, which have been taking place since 1995.

In the course of the study increased concentrations of the analysed elements, i.e. zinc, nickel, chromium, cadmium, manganese, iron, copper and lead, in the investigated road surfaces made from granulated blast furnace slag and furnace slag were observed. The levels of concentrations of these metals in the pavements affected their contents in the ground, groundwater, as well as the needles and leaves of trees growing in the vicinity of the investigated sections of the roads. The analyses did not indicate the effect of the concentrations of metals in the assimilatory organs of trees on their health state determined on the basis of visual assessment of arborescent vegetation morphology. The highest concentrations of the analysed elements were detected in the pavement made from granulated blast furnace slag, a material not recommended for forest road surfaces without having a prior chemical analysis conducted on its composition.

The experiment described was established in 1974 in the Wronki Forest Inspectorate, the Smolnica Forest District. The conditions of this plot were described as dry pine forest site and the growth of Scots pine was analyzed in a 25-year-old stand, growing on the plot with different soil preparation. After 25 years a positive influence of these treatments on the taxation features (diameter at breast height, height and volume) of Scots pine, intensity of self thinning and biological structure were analyzed. The obtained results were then elaborated statistically.

The study was conducted in the Game Investigatory Centre “Zielonka” situated about 25 km north of Poznań. The study area encompasses 13000 ha, including 7500 ha of forested area. Currently, the area is populated by one of the best in quality population of fallow deer in Poland, which comprises up to 300 animals. As a result of a three-year- -long research a simil size and the overlapping of the home ranges have been found.

The aim of the work was searching of differences among analyzed, used in forest typology, elements of soil, allowing to differentiate degraded deciduous mixed fresh forest, deformed coniferous mixed fresh forest and coniferous fresh forest. The results of the work point out the range where there is no possibility of univocal differentiation of the investigated habitat types of forest.

The article presents the method of estimating the stand stability and the results of its practical application. The index of global stand stability is calculated by averaging the partial stability values belonging to the selected stand attributes. The selection of the attributes has been made separately for the following stand developmental stages: young stand, thicket, middle-aged stand and mature stand. The main attributes influencing the stability of the tree stand are forest sites, tree species composition, type of stand establishment and stand tending effects (stand density, diameter structure, H/D ratio). The method has been tested in the Lipce Forest (experimental forest of Warsaw Agricultural University in Rogów) including 245 stands covering 885.35 ha. The results of the test show that around 2/3 of stands (mainly young stands and mature stands) are stable (state 1) and satisfactorily stable (state 2). The rest of the stands (mainly thickets and middle-aged stands) are threatened by instability – 28% (state 3) or are already instable – 5% (state 4).

The comprehensive research on properties of dust wastes arising during the sanding of surfaces of furniture elements made of softwood, which is often used in this production, was undertaken. The results bring an essential contribution to creating a solid ground for dust elimination in furniture factories. These results describe in detail basic properties of wooden dusts from longitudinal and transversal sanding with various abrasive materials. A specialist dealing with elimination of dust in softwood working industrial plant receives information allowing designing of pneumatic equipment that pipes off the dusts from the working zone, an installation of transport to destination, and dust extraction centre, which is a barrier to their emission into the environment. Practical usefulness of the given results is their main feature because sanding materials typical of basic equalising and smoothing sanding operations on furniture elements were used in the research. These materials were used for working on the most important kinds of softwood in furniture production.

The length of the wood fibers and vessel elements was found to increase with the cambial age of the rings increasing from 3 to 12. This reflects a weak increase in fiber and vessel member lengths from the very beginning of annual increment up to ?-? of its width and then toward decrease in the length value until the growth ring ends. The vessel members diameter does not depend on the vessel location in the annual increment.

The performed investigations focused on the effect of the feed rate on wood surface roughness. The experimental material comprised samples obtained from beech sawn timber. The machine tool used in the described experimental material was a vertical frame sawing machine of DTPC-71 type. On the basis of measurements and calculations of some selected parameters of surface roughness: Ra, Rmax, Rz and Rm, the authors found a correlation between the feed rate and wood surface roughness.