The effect of initial spacing on wood density and biometric properties of fibers in Populus deltoids (Case study in Sari region)

The wood and paper factory of Mazandran has been planting poplar species at various initial spacings in order to raw material for pulp and paper production. Initial spacing can affect the value of stem diameter, height, and ultimately the wood quality due to root and crown competition in light, water and food production. In the present study, the effects of initial spacing and axial position on the oven-dry density and biometrical properties of Populus deltoids were examined.
Nine normal poplar trees (Populusdeltoids) were randomly selected in three initial spacings (2×2, 2×3, 3×3 m) from Mazandran wood and paper industries forest. Three samples were taken along axial position from bottom to upward (breast height, 50 and 75% stem height) to determine wood density and fiber biometrical properties (fiber length, fiber diameter and cell wall thickness, slenderness ratio, flexibility coefficient, and runkel ratio).
Results of ANOVA indicated that the initial spacings had significant differences on the density, fiber dimensions, and slenderness ratios and hadn’t on the flexibility coefficient and runkel ratio. The effect of longitudinal position on density and fiber biometry wasn’t significant. Interaction effects between initial spacing and longitudinal position on the wood properties wasn’t significant except in fiber diameter. The highest and lowest of oven-dried density, fiber length, fiber diameter, cell wall thickness and flexibility coefficient were found at initial spacing 2×2 and 2×3, respectively. The average of slenderness ratio and runkel ratio in 2×3 is higher than other initial spacings. There are significantly positive relationships between stem diameter and height grows with density and fiber dimensions in poplar wood.
According to the obtained results, it can be said that planting in lower initial spacing is more suitable than other initial spacings for pulp and paper production.