How do soil resources affect herbivory in tropical plants along environmental gradients? : a test using contrasting congeneric species.

Abstract

Plants adapted to different habitats exhibit

differences in functional traits and these characteris- tics are influenced by soil properties. We tested the

hypothesis that soil resource availability influences the

functional traits of plants, affecting therefore her- bivory levels. We examined three Byrsonima plant

species with different life forms that occurred across a distinct edaphic habitat along the Doce River Basin, South-eastern Brazil. We characterized habitats according to soil nutrient concentration and measured functional characteristics of crown architecture, leaf nutrients, sclerophylly, leaf area and leaf density. In addition, we evaluated how these variables influenced herbivory levels of congeneric plants. Our data show that species along a gradient of soil nutrients have functional characteristics influenced by habitat, which

in turn affect herbivory levels. By comparing con- geners with different life forms found along a stress- gradient of continuous habitats, we describe a corre- sponding gradient of plant functional traits and tissue

consumption by herbivorous insects.