Light environment, sapling architecture, and leaf display in six rain forest tree species

Architecture and leaf display were compared in saplings of six rain forest tree species differing in shade tolerance. Saplings were selected along the whole light range encountered in a forest environment. Species differed la rgely in realized height and crown expansion per unit support biomass, but this could not be related to differences in shade tolerance. The results de monstrate that there exist various solutions to an effective expansion of p lant height and crown area. It is argued that choice of the study species a nd the ontogenetic trajectory regarded determine to a large extent the outc ome of interspecific comparisons. No evidence was found that pioneers were characterized by a multilayered and shade tolerants by a monolayered leaf d istribution. Yet, sun plants had a similar crown area, a deeper crown, and a higher leaf area index compared to shade plants and their leaves were mor e evenly distributed along the stem. This suggests that differences in leaf layering are found between plants growing in different light environments, rather than between species differing in shade tolerance.