FACE Technology: Past, Present, and Future -- Case Studies -- The Effects of Free-Air [CO2] Enrichment of Cotton, Wheat, and Sorghum -- SoyFACE: the Effects and Interactions of Elevated [CO2] and [O3] on Soybean -- Paddy Rice Responses to Free-Air [CO2] Enrichment -- Growth and Quality Responses of Potato to Elevated [CO2] -- Responses of an Arable Crop Rotation System to Elevated [CO2] -- Short- and Long-Term Responses of Fertile Grassland to Elevated [CO2] -- Impacts of Elevated CO2 on a Grassland Grazed by Sheep: the New Zealand FACE Experiment -- Responses to Elevated [CO2] of a Short Rotation, Multispecies Poplar Plantation: the POPFACE/EUROFACE Experiment -- The Duke Forest FACE Experiment: CO2 Enrichment of a Loblolly Pine Forest -- Impacts of Elevated Atmospheric [CO2] and [O3] on Northern Temperate Forest Ecosystems: Results from the Aspen FACE Experiment -- CO2 Enrichment of a Deciduous Forest: The Oak Ridge FACE Experiment -- Long-Term Responses of Photosynthesis and Stomata to Elevated [CO2] in Managed Systems -- Carbon Partitioning and Respiration - Their Control and Role in Plants at High CO2 -- The Response of Foliar Carbohydrates to Elevated [CO2] -- Processes -- Evapotranspiration, Canopy Temperature, and Plant Water Relations -- Biological Nitrogen Fixation: A Key Process for the Response of Grassland Ecosystems to Elevated Atmospheric [CO2] -- Effects of Elevated [CO2] and N Fertilization on Interspecific Interactions in Temperate Grassland Model Ecosystems -- The Potential of Genomics and Genetics to Understand Plant Response to Elevated Atmospheric [CO2] -- The Impact of Elevated Atmospheric [CO2] on Soil C and N Dynamics: A Meta-Analysis -- The Influence of Elevated [CO2] on Diversity, Activity and Biogeochemical Functions of Rhizosphere and Soil Bacterial Communities -- Increases in Atmospheric [CO2] and the Soil Food Web -- Perspectives -- FACE Value: Perspectives on the Future of Free-Air CO2 Enrichment Studies. Managed ecosystems cover a large part of the Earth's land surface, provide almost all of our food and most of our wood and fibre, and are increasingly a source of renewable energy. Forecasting the ability of managed ecosystems to continue these vital roles in a globally changing environment is an inter-disciplinary challenge. To elucidate the complex responses of managed systems to elevated [CO2], several free air carbon dioxide enrichment (FACE) facilities were established. These FACE systems allow large areas to be exposed to the elevated [CO2] we expect by the middle of the century. This volume summarizes the main findings from 13 experiments with annual crops, permanent pastures and plantation forests at 11 sites throughout the world during the past ten years. The results significantly alter our perception of how rising [CO2] will directly affect these managed ecosystems, with implications for policy, plant-breeding objectives and adaptation.