Penentuan Masa Transisi Kayu Juvenil ke Kayu Dewasa pada Bagian Tengah Batang Sengon (Falcataria moluccana (Miq.) B. Grimes) dan Jabon (Anthocephalus cadamba Miq.)

Abstract

Sc. Wood is an important forest resources which has been processed in large quantities to meet growing human needs. To meet the increasing demand for wood, wood supplies are able to be taken from fast-growing species planted in plantations and community forests. These fast growing species tend to be harvested in short rotation and have a high proportion of juvenile wood. The objective of this research is to determine the characteristics of juvenile wood in order to use wood Jabon and Sengon properly. The approach of segmented regression model is used to describe the development of juvenile wood to mature wood while non-linear procedures at the level of two orthogonal polynomial equation is used to identify the starting point of the formation of mature wood. To determine the transition of juvenile to mature wood in Sengon and Jabon, samples of two trees with ages 5, 6 and 7 years are taken from the community forest in Sukabumi. Disk with a thickness of 5 cm is taken at a height of 3.5 meters from each sample tree for measuring fiber length, MFA, density and moisture content. Wood moisture content from pith to bark is measure by using gravimetric method. Fiber length and MFA are measured on each circle grows as wide as 1 cm from pith to bark by using maceration and microtome technique. That was an analysis of segmented regression model in radial to fibers and MFA, showing that Sengon and Jabon wood were young wood until the age of 7 years. Fiber length and MFA were the best indicator to determine the transition from juvenile to mature wood, although the transition point varied to their properties. The proportion of juvenile wood on Sengon and Jabon wood at the age of 7 years were respectively 80-100% and 100%.