Now let's take a closer look at juvenile wood, and compare it with mature wood. Juvenile wood is added within and just below the live crown.
Production gradually shifts to mature wood as the distance from the centre of the crown increases.
As the crown lifts, a core of juvenile wood develops within a shell of denser mature wood which is relatively strong, stiff and less likely to warp when cut into boards. Here relative density, an important component of wood quality, characterizes the juvenile to mature wood transition at breast height. Pith to bark changes in fiber length and fibril angle are similar except that the pattern of the latter is reversed. The density drops briefly, and then rises rapidly before crossing an arbitrary boundary which defined mature wood in the previous figure. Now watch TASS simulate the development of juvenile and mature wood.