The goal of this organized oral session is to highlight the spectrum of current and potential research in above-belowground interactions, and in doing so to inspire attendees to push the boundaries of their research beyond the typical scope of above-belowground research. Plants exist as part of two dynamic and diverse systems: the above-ground system and the below-ground system. Research suggests that the above- and below-ground systems often interact in unpredictable and surprising ways. For example, belowground herbivores can alter plant volatile blends thereby modifying plant signals to higher trophic levels. Belowground herbivores can also alter the feeding preferences of above-ground herbivores on host plants, while soil organisms such as mutualists, pathogens, and even worms can alter plant physiology, secondary chemistry, and attractiveness of host plants to herbivores and pollinators. Moreover, the above-ground systems can also alter resource allocation and root exudation in ways that influence root and rhizosphere organisms. The evolutionary significance of these interactions often remains uncertain and challenges current ecological thinking (as in the case of the plant optimal defense theory of herbivory). By bringing together researchers investigating above-belowground interactions across the spectrum of ecology from genomics through to ecosystems, we aim to highlight both ends of this spectrum and thereby begin to address the next generation of research questions in this field. The organized oral session will begin with researchers manipulating single genes and researchers comparing the influence of genotypes on the outcome of above-belowground interactions. This will then be expanded to address the evolutionary consequences of genotypes which will lead into presentations of research conducted at the population and community level. Our final speakers will wrap up by identifying the consequences of above-belowground interactions at the ecosystem level and address the overall significance of these interactions. The 2012 ESA Meeting Theme (Life on Earth: Preserving, Utilizing, & Sustaining our Ecosystems) highlights the importance of the full spectrum of the definition of biodiversity which includes both genetic and ecosystem effects. In this organized oral session we will emphasize the full spectrum (from genomics to ecosystems) of the diversity of species interactions. As a result, this organized oral session will both address the meeting theme as well as capture the broad interests of ESA members due to the diversity of topics and the spectrum of ecological fields covered.