An Investigation of Annual Ring Width and Physical, Biometry Properties of Nnatural and Planted Alder Wood (Case Study in Zirab Forest)

The present study was carried to investigate annual ring width, physical and biometry properties of natural and plantation of alder wood. For this purpose six trees of natural and planted alder trees were selected from Zirab-Savadkouh city of Mazandaran province. A log of -15 cm thickness was taken at breast height from each tree for biometry, physical propeties and annual ring width. Binocular system was used to determine annual ring width along radial direction from pith to the bark. Three samples were prepared along radial position from the pith to the bark to examine physical and biometry properties, then wood data were analysed by SPSS software. Analysis of variance (ANOVA) indicated that there are significant differences between natural and plantation alder tree in fiber length and slenderness ratio. The plantation condition did not show significant difference regarding the annual ring width, oven-dry density, basic density, volumetric shrinkage, volumetric swelling, fiber diameter, cell wall thickness, Runkel ratio and flexibility coefficient. The amount of fiber length and slenderness ratio in plantation of alder tree was higher compared to natural alder trees. Positive relationship was found between wood density and shrinkage in both species, while this relationship in natural alder tree was about 50% higher than plantation of alder forest.