Global Atmospheric Change and Trophic Interactions: Are There Any General Responses?

Abstract

Increasing atmospheric CO 2 is hypothesized to alter plant physiology and metabolism, which may have important implications for species interactions. In this chapter, we review published studies on the effects of elevated atmospheric CO 2 on plant-derived allelochemicals and the possible effects of CO 2 -mediated changes on higher trophic levels such as herbivores, parasitoids, and predators. We provide a critical assessment of conventional ecological theories used to predict phytochemical responses to CO 2 and we make some suggestions as to how this field may be expanded and improved.