Stand growth scenarios for jabon (Anthocephalus cadamba Miq.) plantation management in Indonesia
Stand growth and management scenarios were developed for four different site qualities and three different initial stand densities of jabon (Anthocephalus cadamba Miq.) plantations in Indonesia. The objective was to analyze the differences in growth and yield generated for each management scenario and to find the most suitable scenario for maximizing timber volume. The scenarios were simulated based on growth curves generated for tree diameter and height, based on measurement data from 144 plots over six sites in Indonesia. The results indicated that among the 12 combinations of site quality and stand density, the rotation periods varied from age 10 yr to 20 yr, and the final density varied between 220 trees/ha and 367 trees/ha. The mean annual increment of timber volume at the end of the rotations was 8.0–21.2 m3/ha/yr, thus accumulating a total timber volume of 122.4–317.5 m3/ha over the rotation. The most feasible options for thinning in terms of intensity, number of trees and timing varied depending on the site quality and stand density. The two most suitable scenarios for jabon were on high-quality sites with initial stand densities of 1,667 and 1,111 trees/ha; both with three thinnings (intensities of 30–60% removal of the number of trees) and rotation ages of 15 yr and 13 yr, respectively. These two scenarios yielded very similar values of timber volume extracted at the final regeneration cutting (176.5 m3/ha and 180.4 m3/ha) with mean annual volume increments of 21.2 m3/ha/yr and 20.9 m3/ha/yr, respectively.