Plant Ecology

, Volume 132, Issue 2, pp 121–136

Spatial distribution patterns of two predominant emergent trees in a tropical rainforest in Sarawak, Malaysia


  • Akira Itoh
    • University Forest, College of AgricultureEhime University
  • Takuo Yamakura
    • Department of Biology, Faculty of ScienceOsaka City University
  • Kazuhiko Ogino
    • Laboratory of Forest Resources, College of AgricultureEhime University
  • Hua Seng Lee
    • Forest Department of Sarawak
  • Peter S. Ashton
    • Arnold ArboretumHarvard University

DOI: 10.1023/A:1009779424279

Cite this article as:
Itoh, A., Yamakura, T., Ogino, K. et al. Plant Ecology (1997) 132: 121. doi:10.1023/A:1009779424279


Spatial distribution patterns of two emergent tropical rainforest tree species (Dryobalanops aromatica & D. lanceolata) were examined in where they were dominant (17–20% of total basal area of canopy trees) in Sarawak, East Malaysia. Newly established seedlings (< 2 years old) were restricted to areas < 40 m from mother trees for both species, suggesting a limited seed dispersal. Seedling (< 1 cm in dbh) density was highest around conspecific adults (≥ 30 cm in dbh). Negative spatial patterns were observed between larger juveniles (1–5 cm in dbh) and conspecific adults for both species; the most dense populations of sapling (1–5 cm in dbh) and poles (5–30 cm in dbh) were found at a distance of 15–20 m from the nearest conspecific adult. Seedlings of both species were distributed randomly with respect to light conditions evaluated by a forest floor diffuse site factor and a canopy closure index. Saplings of both species, and poles of D. lanceolata, were distributed under more open conditions than expected from spatially random distributions, and from average light conditions of all species of the same size classes. Possible mechanisms for the observed distribution patterns and intermediate canopy dominance of Dryobalanops were discussed from the viewpoints of gap-dynamics and distance-dependent mortality.

CoexistenceDipterocarpaceaeDryobalanops aromaticaDryobalanops lanceolataGap dynamicsJanzen-Connell hypothesis

Copyright information

© Kluwer Academic Publishers 1997