The stumps left after trees damaged by lightning were invaded by 20 species of insects, mainly characteristic for weakened trees. Among them the Scots pine (Pinus sylvestris) stumps inhabited by Rhagium inquisitor were the most abundant (79%). Norway spruce (Picea abies) stumps were inhabited in 48% both by Xyloterus lineatus and Hylurgops palliatus. Stumps of other trees such as silver fir (Abies alba), Douglas fir Pseudotsuga menziesii, European beech (Fagus sylvatica) and pedunculate oak (Quercus robur) were inhabited in 23-27% by Rhagium inquisitor (Abies alba), Xyloterus domesticus (Pseudotsuga menziesii), Rhagium mordax (Fagus sylvatica) and Agrilus biguttatus (Quercus robur). No signs of insects activity were found in European larch (Larix decidua) stumps. Beside the mentioned species of insects, the presence of Cryphalus piceae in fir stumps and Phaenops cyanea in pine stumps was observed despite, that these species usually inhabit in fact higher parts of trees.

The purpose of this study was to recognize the thermic and pluvial factors affecting the radial increment of partial populations of Douglas-fir growing in the Polish Carpathians. The investigated trees were growing in 12 localities situated in the area from the Silesian Beskid to Bieszczady and the eastern part of the Carpathian foot-hills (Fig. 1). In each locality increment cores were taken from 25 healthy trees. The relationship between the tree-ring width and temperature, as well as precipitation, were analyzed by a linear correlation and multiple regression – response function [Fritts 1976]. It was found that in spite of similarities in the course of chronologies (Fig. 2, 3, Tab. 1), as well as in the models of associations climate-increment (Fig. 6), of different populations of trees there are differences in their susceptibility to thermic and pluvial conditions prevailing in respective regions of the Carpathians. These differences are connected not only with the specific climate associated with the geographic location, but also with microclimatic conditions of the place of their growth. The air temperature of winter (January-March) is the factor having the strongest influence (Fig. 4, 5). While the air temperature and precipitation of summer (July-August) is the main factor differentiating the increment rhythm of Douglas-fir (Fig. 4, 5). However, Douglas-fir seems to be the species which has been well adapted to climatic conditions of the Carpathians, in spite of the fact that even when mature it is susceptible to winter frosts, dry growing season, and deficiency of warmth in summer (Fig. 6).

Studies carried out on twenty plots in the Forest Districts of Czerniejewo and Jarocin were aimed identify at and characterising the site conditions of the Calamagrostio arundinaceae-Quercetum petraeae association in the central part of Wielkopolska. It was found that this association occurs on cambic arenosols, gleyic podzols and haplic luvisols developed from deep fluvio-glacial sands, outwash sands, boulder sands or boulder clays with a high sand content. All soils occupied by Calamagrostio arundinaceae-Quercetum petraeae are highly acidified with strongly leached surface layers, which determines the kind of vegetation ground cover. The productivity of soils and sites is due to the fertility of deep and very deep soil horizons which often contain carbonates. Depending on the trophy of these horizons, various site types have developed, namely a fresh mixed coniferous forest, fresh mixed broadleaved forest or less fertile variants of fresh broadleaved forest.

The reduction of fuel fossil resources and the tendency to limit emission of harmful substances into the atmosphere have influenced an increase of utilization of wood, especially wood chips. The object of performed investigations was to determine the operative labour consumption of technologies applied in wood chips harvesting that nowadays are used in the PGL State Forests. The technologies analysed, differed in the extent to which machines were used. The assesment comprised work output. The technology based on mechanical skidding and chipping with a chipper with a mechanical feeding system was the least labour-consuming. The technology in which horse skidding was used and the wood was chipped with a chipper with a manual feeding was the most labour-consuming. Manual skidding was the most labour-consuming and chip trucking the least, with the exception of technology with horse skidding, which was the most labour-consuming.

The woodiness of Poland in the years 1990-2001 is presented by commune and causes of its spatial differences in the index are explained. An analysis is also made of changes in woodland area and their sources are identified. A significant element of the paper is the presentation of the possibility of an increase in the country’s woodiness level in the future. The research has shown that in more than one-fifth of the communes woodland occupies in excess of 40% of their total area, but there are also those where woodland is a mere 10%. It has also been established that over the years 1990-2001 significant changes occurred in the woodland area of Poland.

During investigations carried out by the questionnaire method, information was collected about means of communication used in units of State Forests, the usefulness assessment of the individual types of equipment for work and the evaluation of the degree of utilisation of the investigated pieces of equipment. In situations, which are not hazardous to the existence of the forest, it is the cell phone that is thought to be the most important (94.4% of those questioned described the usefulness of mobile phones as essential or necessary). The network of radiotelephone communication is essential in situations of threats posed by forest fires or other natural disasters. The remaining tasks carried out with the assistance of radiotelephones are of secondary importance. Data transfer is conducted most frequently using traditional cable phones. A relatively small number of respondents takes advantage of additional facilities and functions offered by various network operators (e.g. 5% uses fax machines and 20% – the automatic secretary).

The study was carried out in 2001-2003, covering 32 stands in 14 forest districts. Except of survey of sample plots, each at least 2500 m², a total of 960 beech trees from all over the Poland’s beech forest zone were subjected to detailed measurements and assessments in order to provide a possibly comprehensive description of different aspects of trees’ vitality status. It is concluded that, despite several threats, the condition of beech stands in Poland should be assessed satisfactorily, in the potentially most vulnerable localities.

In the course of the performed investigations, 4 indices of the volume increment were subjected to basic analysis concerning the main statistical characteristics. The empirical material comprised 94 pine trees derived from an 86-year old pine stand. A complete bole analysis was carried out on cut trees and then, in consecutive 5-year increment periods, 4 indices of the volume increment: C₁, C₂, C₃, C₄ and volume increment intensity as i’. Set against the variability of the volume increment intensity i’, the variability coefficients in the consecutive 5-year increment periods of the volume increment index C₁ were bigger, C₃ and C₄ – comparable and C₂ – smaller than the variability coefficients i’. There was no correlation between the mean of two volume increment indices (C₂ and C₃) and the age of trees. The mean of the C₁ index increased with the age of trees. The C₄ mean declined with the increase of tree age. The population of the volume increment intensity i’ in each increment period was characterised by the distribution which did not differ from the normal distribution. The C₃ index distribution differs for the normal distribution for 1 increment period, of the C₄ – for 2, C₂ – for 6 and of the C₁ – for 12 out of the 15 analysed periods.

Requirement for seeds of Silver fir (Abies alba Mill.) is actually about 17 ton per year. Seeds storage as well as new technologies of seedling material production require production of qualified sowing material. Relatively low vitality of the Silver seeds and small difference between physical properties of vital and dead seeds make necessary application of precision selection equipment. Pneumatic devices are widely used in the separation of seeds of forest trees because they offer many advantages: simultaneous purification and sorting of seeds, no damage to seeds, no change in the physical and biological properties of seeds, continuous regulation of the parameters of separation, high efficiency associated with low dimensions and low energy demand, low level of noise, no air contamination The paper presents the results of investigations into the effectiveness of separation conducted in a pneumatic separator with a vertical air column, designed and produced at the Department of Forest Works Mechanization of the Agricultural University of Cracow.

The dendroflora of the “Olszak I, II” ecological site includes 108 taxons from 25 families. Tree stands are dominated by stands with Pinus sylvestris and Betula pendula but there are also significant numbers of deciduous bushes and trees associated with oak-hornbeam forests, flood plain forests and alder forests. Stand fragments with species composition closest to the natural one can be found in flood plain forests, alder forests and oak-hornbeam forests, primarily in the valley of the Cybina River and the adjacent areas. Although the dendroflora of this land is under a strong anthropogenic pressure, it should be considered as one of the most valuable dendrofloric objects in Poznań. We can find here 4 species under legal protection, 7 species from the regional red list, 20 plants from the list of threatened species in Poznań and 76 trees selected for protection as monuments of nature.

The objective of this study was to present the general situation and conditions of lowland bison breeding in Poland in the years 1997-2000, at four Closed Bison Breeding Stations, the Wolin National Park in Międzyzdroje, the Forest Culture Center in Gołuchów, the Wildlife Park in Kadzidłowo, Municipal Enterprise for Urban Green Areas Preservation in Leszno, and eight zoological gardens.

The objective of the present study was to describe the management of free-ranging bison in Poland, on the basis of four populations of the lowland bison (Białowieża Primeval Forest, Borecka Primeval Forest, Knyszyńska Primeval Forest, Forest Division Wałcz) and one population of the highland or Białowieża-Caucasus bison (Bieszczady Mountains). The analysis concerned their sex structure, herd size, and population dynamics in the years 1997-2000.

Using laboratory wood sample’s tests the ability for wood protection against wood decaying fungi of a group of systemic fungicides was tested. Five different fungicides were examined: Bayleton 25 WP, Benlate 50 WP, Falcon 460 EC, Preventol R 80 and Sarox T 500 FS. As testing fungi two species were used: Laetiporus sulphureus and Trametes versicolor. In the experiment four kinds of samples were tested: made of sapwood and heart-wood of common oak and of wood of external and internal parts of small-leaved lime stem. Among the tested fungicides Falcon 460 EC and Preventol R 80 appeared the most effective. In every case and variant of the experiment, samples protected by them were destroyed much slower as related to control samples. According to these results both Falcon 460 EC and Preventol R 80 seem to be useful in practical wood protection.

The aim of the research was evaluation of effectiveness of conservation of waterlogged archaeological wood with selected chemical compounds, as well as an attempt to find a correlation between a degree of degradation of wood and its dimensional stabilization after impregnation. The tests were carried out on archaeological oak, elm, pine and fir wood. The degree of wood degradation was evaluated on the basis of loss of wood substance and contents of basic chemical components. Wood samples were impregnated with solutions of sucrose, lactitol and polyethylene glycol (PEG) 300 and 4000. The study compares shrinkage of non-impregnated wood with deformation of the modified wood. It presents relations between the uptake of the investigated chemical compounds and a degree of cross-section strain of the wood. The tests showed a large diversification of moisture strains of softwood and hardwood, as well as essential differences in effectiveness of conservation of the archaeological wood with the tested impregnants.

The study investigated the effect of the modification of phenolic resin with organic acid esters, such as ethyl, butyl and pentyl acetates, on the possibility to shorten pressing time of particleboards produced with modified PF resin. Conducted investigations showed that all types of esters added to resin make it possible to produce particleboards with good properties at shortened pressing times. Butyl acetate turned out to be the most effective modifier, as it facilitated shortening of pressing time by 30%.