Variation of fir wood structure from region of Gorski kotar

In this article given are the results of investigation on variation of growth rings width, length, diameter and wall thickness of tracheids and volume percentage of wood rays in juvenile and adult fir wood from region of Gorski kotar. Length, diameter and wall thickness of tracheids rises from pith to approximately 60. growth ring, and later toward the bark remain constant. In the same direction growth rings width fall constantly. Volume percentage of wood structure elements is constant and does not change from pith to bark.