In a changing environment, plants and plant-based communities must be able to acclimate to increasingly severe stresses. This session will focus on plant responses to global change, from molecular and physiological mechanisms of phenotypic plasticity to resulting changes in plant ecology. In particular, the session will explore how plant responses to environmental pollutants affect their ecological interactions with primary consumers (i.e., herbivores) and belowground mutualists. The speakers have been selected to highlight a number of key components of global change and their impact on plant ecology. First, since there are many contributing factors to global change, the speakers will collectively address effects of three key atmospheric factors: elevated carbon dioxide, elevated ozone, and increased nitrogen deposition. Second, as global change does not discriminate taxonomically, the speakers will also cover a range of taxonomic plant diversity, including woody and herbaceous species. Agricultural plants are also subject to a changing environment, and the session includes an agroecological perspective on global change. Third, plant ecological interactions occur both above and below ground, and speakers will address the diverse ecological effects of global change that occur in leaves and roots alike. Finally, predicting the ecological outcomes of plant-based communities and ecosystems in a changing world requires a mechanistic understanding of how plants respond to environmental variation. While maintaining an ecological focus, a number of the speakers in this session will provide a mechanistic view of plant responses to global change. These speakers will bring genomic resources and techniques to bear to describe molecular and physiological regulation of plant responses to global change. The session will start by exploring plant responses to elevated CO2, which is considered a central contributor to global warming. Then, the session will highlight effects of ozone pollution and nitrogen deposition. The session will end by presenting a broad look at global patterns of plant response to environmental change and to highlight future directions for focused research.