Trend of changes in basic density and green moisture content in the vertical and radial ‎direction of hornbeam tree trunks (Carpinus betulus L.) in Hyrcanian forests

The aim of this study was to investigate the trend of changes in basic density and green moisture content of hornbeam trees in the vertical and radial direction of trunk wood. Therefore, a complete disk was prepared from 10 fallen trees in 20-40, 40-60 and 60-80 diameter classes and different decay degrees (grades 1, 2 and 3). The disks were prepared at intervals of 5, 35 and 65% of the vertical sections of the trunk. Then, the sample pieces with a fixed volume of 2× 2× 2 cm3 were fragmented at a ratio of 10, 50 and 90% of the radial sections of the disks and were obtained their basic density and green moisture content. The results showed that the green moisture content and trunk basic density of hornbeam trees in different diameter classes with the degree of decay had a significant difference with a probability of 99% (P <0.001). The highest mean basic density values were observed in the distance of 5% in the vertical direction and 90% in the radial direction of the trunk wood with 0.59 and 0.60 g / cm3, respectively. The highest mean values of green moisture content were observed in 90% in the radial direction of 0.65 and the distance of 5% in the vertical direction of 0.66. Of course, green moisture content in vertical sections showed a significant difference with changing the degree of decay (P> 0.05), but no significant difference was observed in radial sections. The results of correlation showed that basic density has the highest significance correlation with diameter equal to the breast and the lowest significance correlation with the coefficient of moisture.