Jakość techniczna drewna 35-letnich świerków (Picea abies L. H. Karst) rosnących na powierzchni proweniencyjnej w LZD Rogów

The aim of this paper is to investigate and compare structural, mechanical and physical properties of wood of Norway spruce growing on experimental plot in Rogów (central Poland). The planting material consisted of seeds sourced from six selected provenances. Three of them originated from lowlands, while the others have mountain origins (tab. 1). The plot was established in 1975 and the wood was harvested in 2010. Wood samples were prepared and measured according to the Polish Standards describing those procedures. The following properties were subjected to the research and statistical analyses: average tree−ring width, share of latewood, wood density, compression strength parallel to grain, static bending, modulus of elasticity in static bending and the coeffi− cients of compression strength parallel to grain, static bending, and modulus of elasticity in static bending. Results of the investigation were correlated in the frame of each provenance. Wood density determines values of compression strength parallel to grain, static bending and modulus of elasticity in static bending. The higher wood density, the higher values of the mechanical properties. Ordering provenances by the wood density demonstrates the same results as ordering by values of compression strength parallel to grain. The high values of density and mechanical properties prove good technical quality of the analysed wood. The structural properties (the average tree−ring width and the share of latewood) are correlated to the wood density as well. They are additional features to describe wood quality, but are not as accurate as the mechanical properties. The quality of wood from all investigated provenances is high, what makes impossible to distinguish wood from selected provenances using applied features. Wood from Nowe Ramuki and Kartuzy (i.e. lowland) provenances has the best quality parameters, while one from Istebna Bukowiec and Stronie Śląskie (mountain) provenances demonstrated the worst properties (tab. 2). The results do not prove the opinion about the best quality of Norway spruce wood originating from the mountains.