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Comparison of structural properties of ash and alder wood species grown in natural and planted stands
Industrial plantations of the fast growing tree species have increasingly becoming important for meeting the demands for raw materials needed by the forest products industry. Plantation forestry is desirably due to rapid growth rates of trees; however, wood quality is highly affected and might decrease for both pulp production and solid wood products.
In this PhD dissertation, anatomical and physical properties, compression strength parallel to grain and natural durability of fast-growing ash (Fraxinus angustifolia Vahl.) and alder (Alnus glutinosa (L.) Gaertner) grown in different plantation regions and natural stands in Turkey were investigated and statistical comparisons were then made among the species. Plantation and natural grown ash trees were sampled from Adapazarı, Samsun and Sinop, whilst alder trees for the study were obtained from Samsun and Trabzon.
Annual ring width and anatomical properties were determined according to the procedures explained in relevant literature sources. In order to determine physical, mechanical and durability characteristics, the related standards were followed.
For macroscopic investigations, annual ring, late wood width and late wood ratio were evaluated for ash wood; however, annual ring width only was measured for alder wood. For evaluations of microscopic properties of ash wood, tangential diameter of earlywood and latewood vessels, earlywood and latewood vessels in mm², rays in 1mm, cell height of uniseriate and multiseriate rays, length of uniseriate and multiseriate rays, width of rays, length of earlywood and latewood vessels, fiber length, fiber diameter and fiber wall diameter were measured. Tangential diameter of vessels, vessels in mm², rays in 1mm, cell height of uniseriate rays, length of uniseriate rays, length of vessels, fiber length, fiber diameter and fiber wall diameter were measured and evaluated statistically in alder wood.
As physical properties, air-dried density, oven-dried density, basic specific gravity, shrinkage-swelling, fiber saturation point (FSP), maximum water content, amount of cell wall, and amount of void volume of plantation and naturally grown ash and alder wood were measured. For both wood species, compression strength parallel to grain was tested.
In testing of natural durability of the wood species, the brown rot fungi Gloeophyllum trabeum (Pers.:Fr.) Murrill Mad-617-R, white rot fungi Pleurotus ostreatus (Jacq.: Fr.) P. Kumm. PLO 9669 and Coriolus versicolor (L.: Fr.) Quél. COV 1030 were employed.
Results from measurements and tests were evaluated by statistically according to differences between inter and intra properties of wood species grown in planted and natural stands.
Results showed that ash and alder trees grown in planted stands have wider annual ring than the trees grown in natural stands. Microscopic evaluations revealed that each property had significant difference between each region.
Density of ash and alder wood grown in planted and natural stands is higher than the literature values. There was significant difference between planted and natural stands for ash wood but there is no significant difference between inter and intra regions for alder wood. With the increase in density, amount of shrinkage and swelling increased.
Fiber properties of alder wood were found to be more suitable than ash fibers for pulping. There was no significant difference in natural durability between planted and naturally grown ash and alder wood.

In conclusion, annual ring width, density, shrinkage-swelling, compression strength paralel to grain values of planted ash wood were significantly different from naturally grown ash wood and there were no significant difference between planted and naturally grown fewer alder wood properties.