Data from: Ecological convergence of secondary phytochemicals along elevational gradients

Biologists still strive to identify the ecological and evolutionary
drivers of phytochemical variation that mediate biotic interactions. We
hypothesized that plant species growing at sites characterized by high
herbivore pressure would converge to produce highly toxic blends of
secondary metabolites, independent of phylogenetic constraints. To address
the role of shared evolutionary history and ecological niches in driving
variation in plant phytochemistry, we combined targeted metabolomics with
insect herbivore bioassays and with a set of growth-related traits of
several Cardamine species growing along the entire elevational gradient of
the Alps. We observed that Cardamine phytochemical profiles grouped
according to previously-established growth form categorizations within
specific abiotic conditions, independently of phylogenetic relationship.
We also showed that novel indices summarizing functional phytochemical
diversity better explain plant resistance against chewing and sap-feeding
herbivores than classic diversity indices. We conclude that multiple
functional axes of phytochemical diversity should be integrated with the
functional axis of plant growth forms to study phenotypic convergence
along large-scale ecological gradients.