Abstract
The spatial distributions of fallen fruits, seedlings, and trees of Swintonia schwenkii (T. & B.) T. & B. were studied in plots totaling 1.86 ha in a tropical foothill forest near Padang, West Sumatra.We recorded the positions of al1 fruits (2240 mature and 6715 immature), and 572 trees in the plots inSeptember and October 1989. Swintonia schwenkii was the dominant emergent in the plots, and had eightcanopy-to-emergent trees from 36 to 62 m in height. Seven of them produced fruits. There were no S.schwenkii of 20 < H ≤ 36 m in height. An index of spatial association showed that S. schwenkii in these edling-to-pole layer (0 < H ≤ 20 m) tended to be distributed away from those of conspecific emergent trees.
The mature fruits are 2 g in fresh weight, having five wings 6 × 1 cm in size and one seed inside. In contrast with the distribution of seedlings and small trees, many fruits dropped under the crowns of moth-er trees. The number of fruits decreased exponentially with distance from a mother tree, and fruits dispersed further than 50 m were rare.
