Abstract:

Fiber length within trees of plantation of Cinnamomum camphora increases from pith to bark in radial direction and it levels off after the 10～11 rings. Wood basic density decreases from pith to the 4^th ring, then increases gradually and levels off after the 9^th ring to bark in radial direction. The relationship model of fiber length (FB) of camphortree to tree age (x) is FB=626+73.5661x+0.4171x²-0.3639x³+0.0157x⁴-0.0002x⁵(r²=0.9545,1《x《40) and that of wood basic density (BD) is BD=0.4674306/[1+0.095907x³·EXP (-0.1306871x)] (r²=0.8059,1《x《40). Variation of fiber length within a given tree of Cinnamomum camphora is greater than that between trees. Variation of wood basic density and hot-extracts content are distinctly different from fiber length and their variation between trees are greater than those within a given tree of camphor. Juvenile wood range of camphor trees is within 1～7^th or 1～9^th rings near pith. The significant difference of fiber length between juvenile and mature wood within a given tree of camphor was found. No clear differences were found in wood basic density and hot-extracts content between juvenile and mature wood. Growth rate has no distinctly negative effect on fiber length, basic density and hot-extracts content of camphor tree. Variation of wood properties within camphor trees is very small and there is great variation of wood properties between the trees. Stem form of camphor trees is not straight and often lean in stand. Additionally there is more serious interlocked grain within trees. Controlling tree stem form and better its interlocked grain are main ways to improve wood properties of camphor trees through silviculture and tree genetic breeding.

Key words: Cinnamomum camphora, Wood properties, Growth rate, Modelling equations, Variation within trees and between trees