HERBIVORY AND ITS CONSEQUENCES

We argue that herbivores often induce nonlinear or biphasic growth and development in plants. Collectively these individual responses translate into a system-level optimization curve wherein at low levels of herbivory overall community responses show increases in production potential, whereas extreme herbivory causes extreme reduction in productivity. The transition between these two states defines a point of optimal herbivory in respect to C and N processes. We present four case examples from the literature demonstrating such nonlinear responses, suggesting a widespread existence for this herbivore-plant phenomenon. The nonlinear responses appear to demonstrate temporal and spatial scale dependencies.