Community structure, population dynamics and biomass estimation of Bombacaceae in the 50 ha plot at Pasoh Forest Reserve, Negeri Sembilan, Malaysia

Abstract

A study was carried out to determine the population dynamics and biomass estimation of Bombacaceae in the 50 ha plot at Pasoh Forest Reserve, Negeri Sembilan. Census data for the year 1985, 1990, 1990, 2000 and 2005 were obtained from the Forest Research Institute Malaysia, Kepong. The study was mainly focused on data of the year 2005. Nevertheless, comparisons between each census year were carried out to observe variations between each census. Based on the 2005 data, a total of 1,152 stems of Bombacaceae was recorded, representing three genera and five species. Durio recorded the highest number of stems with 950 individuals. The species with the highest total number of individuals was Durio griffithii with 781 individuals. Tree class size of 1.0–9.9 cm, consisting of 840 stems, accounted for 72.92% of the total abundance. The growth rate was 0.06 cm/year and the total basal area measured 0.19 m2/ha. Through distribution pattern analysis using Morisita’s Index of Dispersion (Id), Bombacaceae shows a clustered pattern distribution, with value Id = 11.46. The stimation of biomass for the year 2005 was at 2.24 t/ha, with above ground biomass at 1.98 t/ha and below ground biomass at 0.27 t/ha. Durio has the highest biomass with an estimation 2.09 t/ha, while Durio griffithii contributed to an estimated 1.01 t/ha of the biomass. A total of 237 stems were found dead (12 stems/year) and 118 new recruitments (6 stems/year) had been recorded.