EASTERN U.S. FORESTS PROVIDE AN IMPORTANT ECONOMIC AND CULTURAL RESOURCE AND ARE RESPONSIBLE FOR SEQUESTERING 40% OF THE REGION'S CARBON EMISSIONS. SUSTAINABLE FOREST MANAGEMENT (SFM) PRACTICES ARE ESSENTIAL TO OPTIMIZE THESE ROLES AND ENSURE THAT FORESTS OF THE FUTURE WILL BE RESILIENT TO PROJECTED CHANGES IN CLIMATE. TO MAXIMIZE THE SUCCESS OF SFM PRACTICES, WE NEED TO UNDERSTAND HOW ENVIRONMENTAL CONDITIONS WILL CHANGE, AND HOW TREES AND FORESTS WILL RESPOND TO THAT CHANGE. IN THE EASTERN U.S., SPRING AND SUMMER DROUGHTS ARE PREDICTED TO BECOME MORE FREQUENT IN THE COMING DECADES. HOW EASTERN FORESTS WILL RESPOND TO DROUGHT, WITH REGARDS TO CARBON SEQUESTRATION AND BIOMASS PRODUCTION, IS POORLY UNDERSTOOD DUE TO CRITICAL KNOWLEDGE GAPS AND INCONSISTENT CLASSIFICATIONS OF DROUGHT TOLERANCE FOR THE DOMINANT SPECIES. THE PROPOSED RESEARCH SEEKS TO ADDRESS THIS LIMITATION THROUGH A 3-FOLD APPROACH: USING A COMBINATION OF NEWLY DEVELOPED AND TRADITIONAL PHYSIOLOGICAL METHODS TO MEASURE INDIVIDUAL TREE DROUGHT SENSITIVITY AT A FOREST PRECIPITATION MANIPULATION EXPERIMENT TO REVEAL THE MECHANISMS UNDERPINNING TREE-LEVEL DROUGHT RESPONSES (AIM 1), SURVEYING NITROGEN AND WATER-USE TRAITS AT 7 EDDY FLUX SITES THAT HAVE EXPERIENCED DROUGHT TO IDENTIFY THE DRIVERS OF ECOSYSTEM LEVEL DROUGHT RESPONSES (AIM 2), AND MODIFYING AN ECOSYSTEM MODEL (PNET) WITH THE INFORMATION LEARNED IN AIMS 1 AND 2 TO FORECAST CARBON SEQUESTRATION AND BIOMASS PRODUCTION UNDER VARIOUS CLIMATE AND MANAGEMENT SCENARIOS (AIM 3). THROUGH THIS WORK WE WILL BE ABLE TO PROVIDE PRACTICAL INFORMATION TO VARIOUS STAKEHOLDERS THAT WILL INFORM SFM IN THE EASTERN U.S.