The objective of the presented studies was the determination of Armillaria species causing root rot in stands growing in habitats of a higher fertility in the Siemianice Experimental Forest District. With the application of the mycelium intersterility test, the occurrence of A. gallica and A. ostoyae was found on the area of the mentioned Forest District, while in the nearby situated Mansion Park, Armillaria cepistipes was identified.

Thermal modification of the oak wood causes changes of the characteristics of wastes resulted from wood processing. The waste particles of thermally modified oak wood are characterised by a higher degree of crumbling and clearly different shape. It influences, first of all increasing of the main bulk characteristics of the wastes – bulk density and tapped bulk density. Slight differences in the scope of the angle of repose, the sliding angle of repose and the entrainment velocity of particles including in the same fractions appeared. The exact knowledge of the range of characteristics changes of the wastes resulted from the thermally modified oak wood in the relation to wastes from natural oak wood makes possible the introduction of suitable corrections by establishing the design data for pneumatic conveyors and dedusting devices of woodworking machines applied in the processing of the thermally modified oak wood.

This study evaluated the applicability of particles of white mustard straw as a substitute of wood chips in the manufacture of particle boards, resinated with UF resin. The scope of work included the determination of suitability of mustard straw in the manufacture of particle boards, the manufacture of boards with different proportions of straw and the determination of their basic physico-mechanical properties. Produced single-layer particle boards contained 10, 25, 50, 75 and 100% mustard particles in relation to chip mass. Recorded results indicated that straw of white mustard may constitute a valuable substitute of wood chips in the production of general use particle boards and interior boards, including furniture, used under dry conditions. It was also shown that partial substitution of wood chips with particles of mustard straw in case of boards with density reduced by 30%.

In the work, an attempt was made to evaluate quickness of mycological biodegradation of paper products, with various percentage content of cationized starch and resinous glue, with help of FT-NIR spectrophotometric analysis. As a biotic factor – Ch. globosum axenic culture and mixture of microfungi: A. niger, T. viride, P. funiculosum were used. As a criterion of biodegradation, one assumed resistance to overgrowth of samples’ surface by test mycelium, and determined self-breaking, having completed mycological test on the 2^nd , 4^th , 7^th , 10^th and 14^th day of observation. For the needs of research, one selected cellulose sulfate bleached deciduous pulp from which, together with the above listed pulp additives, sheets of paper were created, everything in laboratory conditions. Starch and resinous glue additives as packing of deciduous pulp caused an increase of susceptibility to overgrowth by test fungi, in comparison to samples without any additives. Paper products infected by Ch. globosum microfungus, generally showed bigger tendency towards biodegradation. Usage of FT-NIR spectroscopy allowed to analyse the complex process of degradation of ligno-cellulose material Changes in the case of peak intensity of degraded waste paper pulps, were mainly noticed in the case of functional groups of cellulose C-H (4280 cm^-1), C-H₂ (4404 cm^-1), and O-H groups (range 4620-4890 cm^-1). Simultaneous usage of several independent methods of degradation degree evaluation, enabled objective interpretation of results, and the carried analyses mutually support the obtained research results.

Chemical composition of selected exotic wood species derived from the area of Africa was investigated by determining the contents of: cellulose, lignin, holocellulose, pentosans and substances soluble in organic solvents, in 1% NaOH solution, in cold and hot water, as well as the contents of mineral substances. The performed investigations revealed that concentrations of the determined constituents in individual wood species varied despite similar site and climatic conditions.