DIFFERENCES IN VEGETATIVE MORPHOLOGICAL TRAITS CAUSED BY HABITAT MEDIATES HERBIVORY RATES IN A PERENNIAL HERB

Resumo

Distinct environmental conditions caused by different habitats may promote the development of different plant morphological traits. These different morphologies may alter a plant's relationships with other organisms in the community (e.g. through herbivory or trophic cascades). We studied plant traits and herbivory rates in Ruellia brevifolia specimens in different habitats, and hypothesized that plant vegetative morphological traits are linked to the habitat, and herbivory rates will be higher in habitats with bigger plants. We measured the morphological traits of plants in 10 'Cerrado' areas and 10 'Mata Seca' areas and surveyed the herbivory levels in each area. We tested the influence of the habitat on the plants' traits using generalized linear models (GLM's). We used GLM's to compare herbivory rates between habitats and analysis of covariance in order to compare the relative impacts of herbivory on both populations of R. brevifolia. Habitat strongly influenced plant morphology, and all the measured plant traits were higher in the 'Mata Seca' habitat. The relationship between herbivory levels and plant morphology was straightforward and depended on plant size. We suggest that future studies may focus on chewing insect communities and light variation in different habitats to verify their relationship with the observed herbivory levels.