PREDICTING INTRATREE AND INTERTREE VARIAB ILITY OF WOOD DENSITY IN SESSILE OAK (QUERCUS-PETRAEA LIEBL) THROUGH MODELING EARLYWOOD AND LATEWOOD WIDTH AND DENSITY FROM CAMBIAL AGE, RING WIDTH AND HEIGHT IN THE TREE

The oak wood intraring density being considered as an important criter ion of its quality, we studied ring microdensitometric components vari ability (earlywood density, earlywood width, latewood density, latewoo d width). First, we considered the intratree variation of density with cambial age, ring width and level in tree. We used regression methods to establish models of variation with the variables we had considered and we studied parameters of the different models (table II) by analy sis of variance. Within a tree, we showed that earlywood width could b e considered as a constant (fig I)and that earlywood and latewood dens ity were only dependent on cambial age (fig 2). For ring width and cam bial age given, the level in the tree effect was important only on the lowest level of our sampling (tables III and IV). We then studied int ertree density variations on 24 trees collected in northeastern France (table I). We evaluated the site effect and the tree in site effect o n the parameters of the models considered beforehand (table V). We fou nd a 'site' effect and a 'tree in site' effect on some parameters; how ever, these results will have to be carefully assessed because of the relative weakness of our sampling. Nevertheless, we can confirm the im portant wood density variability between trees.