Oak tree differentiation of defense and reallocation strategies in response to herbivore pressure
Plant strategies against herbivory may involve defending themselves by producing plant secondary metabolites (PSM), regrowing to negate injuries from tissue loss (tolerance), or reallocating resources to better defend or protect themselves from further damage. We investigated the strategies of oak plants to minimize herbivory by investment in tannins and reallocation of non-structural carbohydrates. Oak species may differentially invest in defenses and reallocation depending on the intensity and location of herbivore feeding. We simulated the effects of herbivory by removing 25% or 75% of oak tissue, removing either the apical or lateral meristems. The investment in defenses may act as a selective pressure driving herbivore diversity and behavior. Using 12 oak species from different parts of a well-supported phylogeny, we applied five treatments of simulated herbivory, varying in intensity and location. The 12 species were chosen to represent a broad array of geographical and phylogenetic diversity. Using an untransformed statistical analysis, we found that oak species invest differentially in defensive mechanisms. We will also present a more thorough phylogenetic comparative analysis of the data to determine if differences in defense and reallocation strategies are a result of adaptation to herbivory or if defense and reallocation strategies are associated with particular oak lineages.
Perkovich, Cindy L. and Ward, David L.(2019). Oak tree differentiation of defense and reallocation strategies in response to herbivore pressure. Environmental Science & Design Research Initiative. Paper 38.