Abstract:

The radial variation patterns of wood density in Pinus elliottii and Pinus teada planted with different tree spacing in Hunan Province and Jiangsu Province were studied by x-ray wood densitometry. The main results obtained are: 1) Tree spacing affected the radial variation patterns of wood density components mainly on their average levels but insignificantly on the shape of density curves. 2) Tree spacing made significant effects on the average levels of the ring width curves and earlywood width curves, and the shape of ring width curves, earlywood width curves, and latewood width curves. 3) In the light of the results from loblolly pine, tree spacing influenced average ring density in two ways: to change the average level of the intraring density curves and to change the ring width so that it is not always ture that there is a monotonous negative correlation between tree spacing and wood density.

Key words: Wood density, Radial variation pattern, Tree spacing, Pinus elliottii, Pinus teada