Physical Properties of Juvenile and Mature Sycamore Maple s podrucja Medvednice

Physical properties play an important role in predicting wood quality. The aim of this study was to investigate radial variations in physical properties of sycamore maple (Acer pseudoplatanus L.) wood, to determine the border between juvenile and mature wood and to compare them with analogous variations in beech wood. Radial variation of density in absolutely dry condition, maximum density, nominal density, longitudinal, radial, tangential and volumetric shrinkage, maximum moisture content and annual ring width on five sycamore maple trees from Medvednica region in Croatia were determined. Observing the trend curves and comparing average values of physical properties, different zones in the cross section of the trunk were determined. In the first zone, from the pith to about 30th annual ring, more rapid changes in physical properties occurred. It is followed by transitional zone, which ranges roughly from 30th to 40th annual ring. After 40th annual ring, less pronounced changes in measured physical properties occurred. Sharp boundary between juvenile and mature wood zones could not be determined. According to the results, the first zone is considered to be juvenile wood, while mature wood starts after the 30th annual ring. Key words: sycamore maple (Acer pseudoplatanus L.), physical properties, radial variations, juvenile wood, mature wood Fizicka svojstva drva imaju vaznu ulogu u predvidanju njegove kvalitete. Cilj ovog rada bio je istraziti radijalne varijacije fizickih svojstava drva gorskog javora (Acer pseudoplatanus L.), utvrditi granicu izmedu juvenilnoga i zrelog drva te ih usporediti s odgovarajucim varijacijama u drvu bukve. Utvrdene su radijalne varijacije gustoce u apsolutno suhom stanju, gustoca pri maksimalnom sadrzaju vode, nominalna gustoca, longitudinalno, radijalno, tangentno i volumno utezanje, maksimalni sadrzaj vode i sirina godova u drvu pet stabala gorskog javora s Medvednice u Hrvatskoj. Iz dobivenih krivulja i usporedbe prosjecnih vrijednosti fizickih svojstava drva utvrdene su razlicite zone na poprecnom presjeku debla. U prvoj zoni, od srcike do priblizno 30. goda, vidljive su znatnije promjene fizickih svojstava drva. Slijedi prijelazna zona, koja se otprilike proteze od 30. do 40. goda. Nakon 40. goda promjene fizickih svojstava drva manje su vidljive. Ostru granicu izmedu zona juvenilnoga i zrelog drva nije moguce odrediti. Na temelju dobivenih rezultata pretpostavljeno je da je prva zona juvenilno drvo, a nakon 30. goda pocin