Tree growth and potential yield of plantation grown Dryobalanops aromatica of Peninsular Malaysia

The study focused on the growth of 50- to 70-year-old planted Dryobalanops aromatica, potential yield and factors affecting its growth within the research area of the Bukit Lagong Forest Reserve at the Forest Research Institute Malaysia (FRIM). Trees were evaluated on periodic annual diameter increment over a period of four years (1997-2000) consisting of six experimental plots with sizes ranging from 0.21 to 0.96 ha. The observed periodical annual diameter increments (P ) were significantly different between plots and years, with a mean of 0.28 ± 0.01 cm year (ranging from 0.21 ± 0.02 to 0.43 ± 0.04 cm year ). The P already falls below the mean annual diameter increment indicating that growth of the species had passed the culmination point of the mean annual increment. Two of the six plots (2 and 6) had significantly higher P than the remaining plots. Both of these plots had lower stand densities (161 and 184 stem ha respectively) and maintained the highest diameter increments throughout the observation period. The occurrence of a prolonged drought in 1997 did not effect these plots much. Plot 5 with the highest stocking had the lowest rate for P at 0.21 ± 0.02 cm year . Assuming all trees P > 50cm were harvested in 2000, the potential yield ranged from 61.3 to 425.8 m ha .