Abstract
The relationship between radial variation in fiber length, fiber wall thickness and earlywood vessel lumen area and growth rate of natural-grown and plantation-grown keyaki (Zelkova serrata Makino) were investigated. Fiber length increased rapidly during the first 10 years or 2cm from pith regardless of growth rate. Fiber wall thickness showed no distinct pattern or tendency to increase slightly from pith to 10 years. Earlywood vessel lumen area was closely related to early radial growth. Earlywood vessel lumen area increased rapidly to 7cm from pith, and then subsequently increased gradually. It is presumed that wood properties are unstable for 10 years or 7cm from pith.
