Hardness and basic density variation in the juvenile wood of maritime pine

This paper investigates the within- and between-tree variability of hardnes s and basic density in two stands of 11-year-old and 20-year-old maritime p ine trees grown in the south-west of France. A slight increase was found in the inner core hardness of the 11-year-old trees (+13.9 %) and in basic de nsity of the 20-year-old pines (6.5 %) with decreasing tree height. Between the 1st and 13th annual rings of the 20-year-old trees, hardness increased by +49.8 % and basic density by +18.7 % on average. These variations were strongly tree-dependent. A significant correlation was found between hardne ss and basic density, even when each sampling position was considered indep endently. (C) Inra/Elsevier, Paris.