Ecology and Evolution of Young Leaf Defenses in Tropical Rainforest Legumes

University Of Utah, Salt Lake City UT

Investigators

Abstract

Plants and herbivores comprise the majority of the earth's biodiversity and their evolutionary interactions have resulted in an arms race in which plant defenses are met by counter adaptations on the part of herbivores. In tropical forests, the vast majority of herbivory occurs by insects feeding on young rather than mature leaves and there is enormous variation in damage among species, yet we know little of the underlying causes of this variation. Using an approach that explicitly considers the evolutionary history of the interaction, this project will examine the chemical defenses of young leaves of tropical legume trees, and correlate this with other plant defenses, with leaf damage by insect herbivores, and with herbivore life history traits. Methods include analyses of plant chemistry, feeding trials with herbivores to assess toxicity, and field measurement of herbivory, timing of leaf expansion, and diet breadth of herbivores. This project will improve our general understanding of the ecological and evolutionary interactions between plants and herbivores, and will provide data on poorly known tropical forests. In addition, the plants under study have commercial value (fruit), and are used for reforestation and for enriching soil nutrients.