Do plant-plant signals mediate herbivory consistently in multiple taxa and ecological contexts?

Abstract

It is becoming increasingly accepted that plant-plant signals can affect plant defense against herbivores. In a few taxa, both the mechanisms of plant-plant signaling and the ecological consequences are well described. However, the current adaptive explanations for plant-plant signaling rely heavily on many ecological contingencies, such as the behavior of herbivores and genetic structure of plant neighborhoods, making it unclear how frequently plant-plant signaling is important across the plant kingdom. Moreover, these same ecological contingencies mean that it may be beneficial for a plant to release a publicly available cue to coordinate its (or its neighbor's) defenses following herbivory in some cases, but it may be disadvantageous in others. In this paper, we focus on recent studies that expand the taxonomic breadth of plant-plant signaling about herbivores that bring classic plant-plant signaling systems into a broader ecological context, and those that find either no consequence or counterintuitive consequences of plant-plant signaling. There is currently a need to explore plant-plant signaling in taxonomically diverse plants and in various ecological settings. © 2013 Copyright Taylor and Francis Group, LLC.