Effects of phylogeny, traits, and seasonality on invertebrate herbivory damage in a meadow community

Invertebrate herbivory affects the composition of meadow communities by differentially decreasing the fitness of individual species. The ability of individual species to resist herbivore pressure depends on their traits, which are often phylogenetically structured, and changes seasonally. We conducted a field study assessing invertebrate herbivory damage of 17 selected plant species in an oligotrophic wet meadow, aiming to assess the effect of functional traits, specifically leaf dry matter content (LDMC), carbon content (C), nitrogen content (N), carbon-nitrogen ratio (C:N), specific leaf area (SLA), and plant height on invertebrate herbivory damage, while taking into account seasonal dynamics of herbivory and phylogenetic relationships of studied species. Herbivory damage was different among individual species, with the biggest distinction between monocots and dicots. Herbivory was best predicted by LDMC, season, and interaction of height with season. After filtering the effect of common evolutionary history from the model, the effect of C, height, and interaction of C with season became significant. LDMC was the best trait predictor in both models. Unique relative contributions of phylogeny and traits to the model explained variability were 15.4% and 33.9%, respectively (with phylogeny using 3 and traits 6 df), with their substantial overlap (35.7%) emphasizing that traits are considerably phylogenetically structured. The effect of seasonality was rather minor (15%). In this study, we point out to the strong interplay between traits, evolutionary history, and seasonal changes influencing herbivory damage and stress the importance of phylogenetic context when evaluating the effect of plant characteristics in plant-herbivore interactions.