XVI International Botanical Congess

We measured terpenoid concentration [T] and diversity (H') within young (YL) and mature leaves (ML), chemical distances among individuals (using their terpenoid profile) and leaf herbivory damage for trees growing in gaps (G) or in neighbor closed forests (CF). Damage was higher in YL than in ML of both G and CF, and overall damage was greater in G than in CF. H' was similar among leaves from both ages and habitats. [T] of G leaves doubled that of CF leaves. YL and ML from G had the same [T], but that of CF YL was higher than that from CF ML. Chemical distance was higher among G individuals than among the CF ones, distance was similar among G YL and G ML, but distance among CF YL was higher than among the CF ML. Results are discussed under the optimal defense theory and considering the possible reduction of chemical diversity by herbivores in a plant population starting in a gap and maturing in a closed forest.