Temperate forests store large amounts of carbon and provide many critical services to the biosphere, but the future function of these forests is becoming increasingly uncertain as Earth enters a period of unprecedented climatic change. Understanding how temperate forest ecosystems will respond to future environmental conditions is key to predicting their role in the global carbon cycle and effectively managing these ecosystems over the coming century. Unfortunately, the complexities of climate change and the forests that it affects make understanding future forest function exceedingly difficult. To address this challenge, we have established the Forest Responses to Warming Atmospheric CO2 and Drought (FORWARD) experiment - a factorial global change experiment with interacting climate manipulation treatments applied to multiple species of different tree-microbe symbioses. The explicit Objectives of this experiment are to 1) understand the interacting and compounding effects of three key climate change factors (CO2, warming, and drought) on temperate forest trees, 2) specifically assess differences in physiological and growth responses of three major tree-microbe symbioses (AM, EM, and N-fixer), and 3) determine how different responses of symbiotic groups will influence future tree and soil carbon capture and storage.