Wood density in relation to cambial age and ring width was studied in 23 trees of European oak (Quercuspetraea (Matt) Liebl. and Quercusrobur L.) from northeast France, and based on these relationships, a model predicting intratree wood density through cambial age and ring width was developed. Wood density is closely correlated with both cambial age and ring width, but its relationships with cambial age and ring width, to some extent, vary from tree to tree. The variation, however, does not show an appreciable pattern with tree height. The model developed is able to predict satisfactorily the average wood density of growth rings in European oak, and to explain the main part of the variation in wood density of individual trees. Furthermore, the model appears also possible to predict the average density of a given small piece of wood from any part of the merchantable bole of the trees. A general model, however, accounts for a relatively low percentage of the variation because there is large intertree variability of wood density in the species. The simulation results reveal that the dynamic silviculture applied to European oak might result in the production of denser and more uniform (in the sense of the radial variation of wood density) wood, compared with classical silviculture.

Twenty-three trees of European oak (Quercuspetraea (Matt) Liebl. and Quercusrobur L.) were collected from northeastern France to study intratree and intertree variation in the following characteristics: (i) wood density as well as earlywood density and latewood density; (ii) various types of wood shrinkage; and (iii) ring width and its components. Both intratree variation and intertree variation in the three characteristics are significant, but intertree variation is generally smaller. However, the relative magnitude of intertree variation varies with characteristic: intertree variation accounts for about 40% of the total variation in radial, tangential, and volumetric wood shrinkage, 32.5% of the total variation in ring width, and 12.6% of the total variation in wood density. Furthermore, the intertree variation is closely and positively related to the intratree variation: among the three characteristics studied, both intertree variation and intratree variation were highest for ring width and its components, and lowest for wood density and its components. In addition, intratree variation increased remarkably with increasing tree age in these species. In general, intratree variation in wood density and wood shrinkage depends more on cambial age than on ring width. The present study, together with the information available so far, suggests that the quality of European oak wood could be significantly improved.

Various wood shrinkages in relation to cambial age and ring width were examined in 23 trees of European oak (Quercus petraea and Quercus robur) from northeast France. Based on the relationships, individual models were developed for predicting tangential, radial and volumetric shrinkage. The results show that the models developed are able to predict tangential, radial and volumetric shrinkage satisfactorily. The goodness of the models, however, is different from tree to tree, and a general model explains only small amount of the variation because of a large intertree variation of wood shrinkage in the species. The simulation reveals that the dynamic silviculture applied to European oak may result in the production of wood with higher and more uniform shrinkage, compared with the classical silviculture. IntroductionEuropean oaks (Quercus petraea (Matt) Liebl. and Quercus robur L.) are the most important hardwoods in France, and the oak wood in this country is mainly sliced to produce decorative veneers (CTB 1972; Folge and Keller 1973). It was noticed (Folge and Keller 1973;Marchal 1983) that the veneer quality is closely related to wood shrinkage. This wood characteristics is thus considered to be one of the most important quality characteristics in the species. The Wood Quality Research Laboratory has worked over the years on the variability of wood shrinkage in the species (cf. Nepveu 1991) since a better understanding of the variability in this important characteristics helps to process and utilize the wood efficiently.