The Impact of Site Index on Wood Density and Fiber Biometry of Populus Deltoids Clones

The variability of wood density and fiber biometry was determined in four 12-year-old populus deltoids clones grown under two different site conditions in Iran. The values of wood density and fiber length, fiber diameter and fiber wall thickness were obtained and variance analyses were performed considering site and clone as the sources of variation. Components of genetic and phenotypic variations were determined to calculate heritability in its broad sense. The results indicated that site and clone had significant effect on wood density and fiber biometry. The pattern variation of properties showed that the clone 77/51 corresponded to the higher wood density and fiber biometry range in both sites, but the clone 45/51 had the lowest. Also, the wood density of populus deltoids from Safra-baste site in Guilan was higher than that it Shast-kolateh site in Gorgan. For each clone, the mean values of wood density, fiber length and fiber diameter and fiber wall thickness varied between 305.7 - 367.1 kg m , 0.96 - 1.29 mm, 24 - 28.46 µm and 5.02 - 6.25 µm respectively. 3