Food webs or antagonistic ecological networks represent descriptors of trophic interactions in a community. A recent advance in ecological network analysis is the integration of both energy and nutrient fluxes within ecosystems. Chemical constraints on predator-prey interactions may play a key role on food web structure. Web-building spiders are outstanding model systems for the study of predator-prey interactions and network structure because actual predator-prey interactions are relatively easy to quantify. We are combining energetic and stoichiometric approaches to explicitly examine how different web architectures may affect the structure of spider-prey interactions on the basis of prey biomass and flows of C, N, and P along environmental gradients.