Monodominance in an African Rain Forest: Is Reduced Herbivory Important?1

Abstract

ABSTRACTTropical monodominant forests in which one tree species dominates the canopy occur in all three major tropical regions, but few studies have focused on the mechanisms responsible for dominance. This study tests the hypothesis that relative to other species in the community, dominant species are well defended and escape herbivore and pathogen damage. We surveyed the rate of damage on young expanding leaves of seedlings and saplings belonging to eight species within both monodominant Gilbertiodendron dewevrei forests and adjacent mixed–species forests in eastern Congo. Results showed that escape from herbivore and pathogen damage is not a mechanism by which Gilbertiodendron achieves dominance, as it suffered the highest damage level of any species surveyed. Similarly, other sub–dominant common species also suffered high rates of damage. These results are discussed in relation to the phenolic, fiber, and nitrogen content of leaves, and in the context of current theories pertaining to plant–herbivore interactions.