Technical Abstract: We identify and review an approach that views ant species diversity as a consequence of energy flux through an ecosystem. In this bottom-up view, energy apportioned to trophic guilds drives ant community responses to mesoscale variation generated by land-use and other processes. We introduce a conceptual model based upon this idea, and offer an interpretation of some data we have collected in the light of the model. Operationally, the concept focuses analysis upon the relationships between species richness/composition, trophic group identity, body size, and abundance. These attributes are compared among ecosystems that vary in total net primary productivity (NPP) and in how that productivity is divided among plant functional groups. We offer a brief example of how biomass and abundance of three ant trophic groups, large granivores, small granivores and scavengers, differed between two ecosystems that varied strongly in NPP patterns. We emphasize the value of linking ant measurements directly with NPP at mesoscales.