Ontogenetic changes in the phenotypic integration and modularity of leaf functional traits

1.Changes in resource availability, functional demands, hormonal regulation and developmental constraints can promote differences in the expression of leaf traits during plant development and foster changes in the targets of natural selection. As a consequence, the pattern and magnitude of covariation among traits, and therefore their phenotypic integration and modularity are equally expected to change throughout ontogeny. However, these changes have not been described yet. 2.We measured leaf economic, defensive and morphological traits in plants of Turnera velutina and estimated the magnitude and pattern of foliar integration and modularity for juvenile and reproductive individuals. In addition, we assessed the relationship between plant biomass and foliar integration within and among ontogenetic stages. 3.Both the pattern and magnitude of foliar integration changed across plant ontogeny. Foliar integration was lower in juvenile than in reproductive plants, and the pattern of phe...