Growth, defense, and storage responses of 12 oak (Quercus) species to varying locations and intensities of simulated herbivory

The evolution of plant defenses is often constrained by phylogeny. Many of the differences between competing plant-defense theories hinge upon the differences in the location of meristem damage (apical vs. auxiliary) and the amount of tissue removed. We analyzed the growth and defense responses of 12 Quercus (oak) species from a well-resolved molecular phylogeny using phylogenetically independent contrasts. Access to light is paramount for forest-dwelling tree species, such as many members of the genus Quercus. We therefore predicted a greater investment in defense when apical meristem tissue was removed. We also predicted a greater investment in defense when large amounts of tissue were removed and a greater investment in growth when less tissues were removed. We conducted five simulated-herbivory treatments including a control with no damage and alterations of the location of meristem damage (apical vs. auxiliary shoots) and intensity (25% vs. 75% tissue removal). We measured growth, ...