A Study of Fiber Characteristics and Chemical Composition in Paulownia (Paulownia fortunei) of Gorgan Region

Paulownia (Paulownia fortunei) is one of the exotic trees which has been successfully growing in
Gorgan region since twenty five years ago. The eight years old paulownia trees have born hundred
percent juvenile wood, in which fiber length for the first and eighth annual rings were measured 0.800
and 1.11 mm respectively. Postcambial growth of fiber length begins starting from the sixth annual
ring. Fiber diameter and thickness in the first annual ring were 31.00 and 4.14 and in the eighth annual
ring 33.18 and 5.18 micrometers respectively. A maximum coefficient of variation was found for fiber
thickness, while a minimum value obtained for fiber diameter. Minimum fiber diameter variation was
observed starting from first to eighth annual rings, in which fiber indices were measured 26 and 34
respectively. Water soluble extractive material was measured 6.94%, the most among all solutions.
Aceton and aceton+alcohol soluble and extractable materials were 5.05% and 4.88% respectively, very
similar to each other. Average lignin content was calculated as 29.77%, that is pretty high and
comparable with coniferous, lignin content. Cellulose and hemicellulose contents were measured as
45.55% and 24.66% respectively.