Modelling variability of within-ring density components in Quercus petraea Liebl. with mixed-effect models and simulating the influence of contrasting silvicultures on wood density

Ring average density, earlywood and latewood widths and densities were measured through microdensitometry on radial strips. The strips were sawn in two radii sampled at various heights from 82 oaks (Quercus petraea Liebl.) split into stands and regions (24 200 available rings). Mixed models were constructed with age from the pith and ring width as quantitative effects to determine which factors influence wood density components, either region, stand, tree or position in commercial logs. The contribution to the total variability of each tested factor was then assessed. The next step consisted in evaluating the ring average density model established at breast height on a new sampling method. The ring average density model was finally used to simulate the influence of contrasting silvicultures on wood density, the simulation including the between-tree variability for both density and radial growth. ((C) Inra/Elsevier, Paris.).