Influence of age and growth rate on the red heartwood of Pinus laricio

Abstract

Pinus nigra subsp. laricio is greatly valued as a highly productive source of good quality wood. However, the red coloration of the heartwood causes downgrading or considerable output lasses from trunks with a large amount of red heartwood. A study of cores taken at a height of 1.30 m showed that the growth of the heartwood in terms of number of rings is primarily determined by age. The growth of the heartwood and the sapwood measured linearly or by cross-sectional area depends on the age and the speed of growth, which in turn depends on the silviculture rather than conventional forestry provided a major increase in the depth and the cross-sectional area of the sapwood. Introducing heartwood development parameters into growth models should enable the phenomenon to be better understood and should enable the silviculture to be optimised to obtain high quality wood.