As a relatively young science, ecology has yet to assemble a robust theoretical core as has physics, chemistry and even molecular and cell biology. Addressing this deficiency becomes ever more urgent as environmental challenges to human sustainability mount due to anthropogenic global change. This presentation will describe how a network approach to ecology helps address these challenges by integrating core subdisciplines including behavioral, population, community, ecosystem and macro ecology as well as other subdisciplines concerned with the structure and dynamics of ecological systems within virtually all aquatic, marine and terrestrial habitats. More specifically, an “allometric trophic network” theory of ecology will be described based on first principles of organismal bioenergetics, the structure of consumer-resource networks, and the inexorable need for all heterotrophic species to eat while all species including heterotrophs are effectively eaten. Two applications of such consumer-resource theory will be highlighted involving ‘multiplex’ network models of fisheries ecosystems and mutualistic interactions among pollinators and plants. The presentation will conclude by very briefly describing current applications of ecological network theory to forecasting the effects of climate change on massive amounts of carbon regulated by soil food webs and to the sustainability of human-natural networks on islands Polynesians have colonized over the last millennium.