Radial variation of vessel lumen diameter in relation to stem increment in 30 hardwood species

Abstract

Vessel lumen diameter (VLD) is one of the most important anatomical indicators for demarcating juvenile wood and mature wood in hardwoods. In several species, we previously found that the age at which VLD stabilizes (maturation age) and the age at which the mean annual increment in radial stem growth was maximal were approximately the same. In the current study, we investigated the extent to which this relationship is true for 30 species of hardwoods. We found that two types of relation exist between the maturation age of VLD and radial stem growth, i.e., the type in which the maturation age of VLD was similar to the age at which the current annual increment was maximal (Type-I), and the other type in which the maturation age of VLD was similar to the age at which the mean annual increment was maximal (Type-II). Where more than one species was studied for a given genus, the type was shared. Porosity (ring- or diffuse-porous) is not related with maturation type.