Regeneration Process of a Climax Species Calophyllum cf. soulattri in Tropical Rain Forest of West Sumatra

Abstract

All individuals of Calophyllum cf. soulattri Burm. (Guttiferae) were surveyed in two plots set in a tropical rain forest, Padang, West Sumatra. In Pin plot (1.0 ha) covered mostly by mature patch of 50-60 m in height, we found four mother trees of C. cf. soulattri (27-39 m in height), and 2,722 juveniles (0-9 m). Instead of the seedling abundance, the mother trees made fruits only in 1981 during the survey period from 1981 to 1989. They seemed to disperse fruits in the whole area of plot. The seedlings and saplings in a subplot of 14 m² adjacent to a mother tree, 30-38% of them survived from 1981 to 1989 and grew 2.5 cm/yr in height. Bigger juveniles (4-9 m) occurred more often in area apart from mother trees. In Gaja plot (0.86 ha) having more gaps than Pin Plot, only 31 C. cf. soulattri existed, which were 0.7-17 m in height.
The following regeneration characteristics are supposed for this species. 1) Only old and big tree can reproduce, and the dispersal area of propagule is wide; 2) the dispersed propagule can survive around the mother trees; 3) the residual life span after maturation is short, and die before offsprings start reproduction. These characteristics will make a mosaic of two types of patches: one composed of mother tree, seedlings and saplings, and the other of young poles. The patch size will be related to dispersal area. Thus the plant population exists continuously in the same area, while sporadic reproduction events create the mosaic pattern.