Changes of Biometric, Physical and Anatomical Properties of juvenile wood and mature wood of Morus alba tree in Longitudinal and Transverse Directions

In this study, we investigated the biometrical properties of fibers, the physical and microscopic properties of Morus alba wood. For this purpose, three healthy mulberry trees were randomly selected and cut in Babol city (Mazandaran province). Three discs of 5 cm thickness were prepared at breast height, 3 m height, and 4.5 m height. In the transverse direction, the test specimens were cut 2 × 2 cm to 3 cm from the pith to the bark sequentially and examined. Then the biometric properties of fibers including fiber length, fiber lumen diameter, fiber diameter, and cell wall thickness were measured. Also, microscopic sections of wood close to the pith and bark were studied using light microscopy according to the List of International Association of Wood Anatomists (IAWA). Anatomy of the wood near the pith and bark of the Morus alba tree revealed differences. Vessel grouping and its arrangements near the pith were more radially, while these features were more clustered near the bark. Rays in the area of the pith were more heterogeneous, while near the bark, many rays were homogeneous. The mean tangential vessel diameter near the larger bark (237 microns) was greater than that of the near-pith wood (144 microns). The porosity of wood was observed to be ring porous, near the bark, and semi ring porous near the pith. The results also showed that there was a significant difference in both the transverse and longitudinal directions of the Morus alba tree in terms of length, fiber diameter, fiber lumen diameter, and the cell wall thickness. The biometric properties of the fibers increased from the pith to the bark. The mean length, total diameter, fiber lumen diameter and cell wall thickness of the fibers were 1.51 mm, 27.25 µm, 18.74 µm, and 8.5 µm, respectively.