** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** SPRUCE-FIR FORESTS ARE WIDELY RECOGNIZED AS ONE OF THE MOST AT-RISK FOREST TYPES IN THE NORTHEASTERN US DUE TO THEIR SENSITIVITY AND EXPOSURE TO CLIMATE CHANGE. THE COAST OF MAINE HAS HISTORICALLY SERVED AS A CLIMATE MACROREFUGIA FOR SPRUCE FORESTS. HOWEVER, EXTREME OCEAN WARMING, RISING INLAND TEMPERATURES, AND INCREASINGLY VARIABLE PRECIPITATION STRONGLY SUGGEST THAT MAJOR DECLINES IN COASTAL SPRUCE FORESTS MAY BE IMMINENT. UNFORTUNATELY, WE HAVELITTLE KNOWLEDGE ABOUT HOW THESE SPRUCE FORESTS WILL CHANGE AND THE IMPACTS ON FOREST ECOSYSTEM SERVICES. THE OVERALL OBJECTIVE OF THIS PROPOSAL IS TO IDENTIFY THE FACTORS THAT PROMOTE COASTAL SPRUCE FORESTS, ASSESS THE RISKS POSED BY CLIMATE CHANGE, AND DEVELOP TOOLS TO MANAGE FOR RESILIENCE. OUR CENTRAL HYPOTHESIS IS THAT RAPID CLIMATE WARMING MAKES COASTAL SPRUCE ECOSYSTEMS EXTREMELY VULNERABLE TO CLIMATE CHANGE DUE TO THE SPECIES' REQUIREMENT FOR COOL MOIST CONDITIONS, LOW TREE SPECIES DIVERSITY, AND THE REGION'SLIMITED ACTIVE MANAGEMENT. WE WILL ACHIEVE THIS OBJECTIVE BY 1) IDENTIFYING THE FACTORS DRIVING RECENT AND CURRENT TRENDS IN COASTAL SPRUCE DISTRIBUTIONS, 2) QUANTIFYING COASTAL SPRUCE FOREST DYNAMICS AND SENSITIVITY TO CLIMATE STRESSORS, AND 3) IDENTIFYING HOW CLIMATE REDUCES SPRUCE GERMINATION, ESTABLISHMENT, GROWTH, AND SURVIVAL. WE HAVE BROUGHT TOGETHER NINE TOP CONSERVATION ORGANIZATIONS FROM COASTAL MAINE IN THIS MULTIDISCIPLINARY PROJECT TO COPRODUCE THESE RESEARCH OBJECTIVES. WE WILL PRODUCE THE FIRST FINE-SCALE MAPS OF THE CURRENT DISTRIBUTION OF COASTAL SPRUCE FORESTS INCLUDING POTENTIAL LOCATIONS FOR CONSERVATION, MANAGEMENT, AND RESTORATION AS WELL AS GENERATE NEW DATA ON STAND DYNAMICS AND CLIMATE SENSITIVITY TO INFORM LOCAL MANAGEMENT AND CONSERVATION DECISIONS. OUR DIVERSE RESEARCH TEAM ALLOWS US TO BRIDGE SCALES FROM LEAF TO LANDSCAPE, MAKING US UNIQUELY POSITIONED TO IMPROVE MANAGEMENT AND CONSERVATION OF THIS THREATENED ECOSYSTEM.