Juvenile and mature wood characteristics of short and long rotation teak in Java

Teak wood (Tectona grandis) as an important forest resource in Indonesia has been processed to wood furniture in large quantities to fulfill an increasing need of both local and international consumers. To satisfy the increasing demand for wood products, teak wood has been supplied from the State forests (Perhutani) and Community teak plantations. Community teak has been harvested at shorter age rotations (7–10 years) than Perhutani teak (40–60 years). This paper discusses the occurrence and characteristics of juvenile wood in Perhutani and Community teak based on density, shrinkage, bending strength (modulus of rupture - MOR, modulus of elasticity - MOE), fiber length, and microfibril angle (MFA). A segmented modeling approach was used to find the juvenile mature transition. Fiber length and MFA appear to be good anatomical indicators of radial increment demarcation between juvenile and mature wood, although maturation radial increment varies slightly between the fiber length and MFA. The use of radial increment density, shrinkage, MOR, and MOE were not appropriate, because of low coefficients of determination and a large range of radial increment for transition from juvenile to mature wood. The maturations were estimated to start at radial increments 10 and 14 cm from the pith by fiber length, and 11 and 15 cm from the pith by MFA for Perhutani and Community teak, respectively. The projected figures for the proportion of juvenile wood at breast height for Perhutani and Community teak were 65% and 100%, respectively. The results also indicate that short-rotation Community teak was not remarkably inferior in shrinkage, MOE and MOR compared to Perhutani teak, although it was less dense, less attractive and less durable due to lower heartwood content. Therefore, careful attention should be given to the use of the Community teak in some wood-processing technologies.