Height Growth of Engkabang Jantong, Shorea macrophylla (De Vr.) Ashton, in a Plantation Forest in Sarawak.

Abstract

The tree height growth of individual trees of Engkabang :antong (Shorea macrophylla) was monitored in a plantation forest, which was established at the Semengoh forest reserve, Kuching district, Sarawak, Malaysia in 1973. The assessment of tree height growth was repeated fifteen times during 21 observation years. Mean height was 19.3 m at the stand age of 2l years old. The growth trajectories with respect to time after planting were approximated by the simple logistic equation, of which three coefficients were determined by the nonlinear least squares method. The coefficients were the intrinsic growth tate r, cafiying capacity K, and coefficient * g determined by initial conditions. The msan estimated r of 0.2983lyear represented very rapid initial growth of E. jantong compared with Cryptomeria japonica commonly used in Japanese plantation forestry. The repulsive relationship was observed between r and K and framed the r-K continuum, which could visualize a position of an individual along it and suggested a resource limit in partitioning mass and energy into two contrasting biological functions, r and K. Furthermore, unusually large r values for dead trees might be an adaptation against damages caused by planting trees and animal herbivores. All these results were strongly linked with promising properties of E. jantong as a species potentially available in the plantation forestry in the tropics.