MANY TEMPERATE FORESTS IN EUROPE AND NORTH AMERICA ARE RECOVERING FROM A LEGACY OF ACID RAIN, THOUGH RECOVERY OCCURS SLOWLY, AND ECOSYSTEM ACIDIFICATION CAN AFFECT THE AVAILABILITY OF CALCIUM, AN ESSENTIAL PLANT NUTRIENT. FURTHER, INTENSIVE FOREST BIOMASS HARVESTING FOR RENEWABLE ENERGY MAY DEPLETE SOIL CALCIUM STOCKS. THEREFORE, IT IS IMPORTANT TO UNDERSTAND HOW SOIL CALCIUM AVAILABILITY AFFECTS FOREST PRODUCTIVITY AND SOIL CARBON STORAGE OVER LONG TIMESCALES, ESPECIALLY GIVEN THAT THESE FACTORS ARE IMPORTANT BOTH IN CLIMATE REGULATION AND FOR THE QUANTITY OF WOOD AND PAPER PRODUCTS THAT FORESTS CAN PROVIDE. REPLENISHING SOIL CALCIUM AND AMELIORATING ACIDIFICATION CAN IMPROVE TREE GROWTH AND SURVIVAL IN SOME SPECIES, AND IT CAN ALSO EXERT STRONG INFLUENCES ON SOIL CARBON STOCKS. THE FACTORS GOVERNING SOIL CARBON RESPONSES TO CALCIUM ADDITION ARE CURRENTLY UNRESOLVED, THOUGH EVIDENCE SUGGESTS THAT CHANGES IN BELOWGROUND CARBON ALLOCATION BY TREES ARE LIKELY INVOLVED, IN LINE WITH INCREASING RECOGNITION OF THE IMPORTANCE OF BELOWGROUND CARBON INPUTS FOR SOIL CARBON DYNAMICS. THE PROPOSED RESEARCH SEEKS TO ADDRESS THIS KNOWLEDGE GAP BY QUANTIFYING THE LONG-TERM EFFECTS OF CALCIUM ADDITION ON ABOVEGROUND-BELOWGROUND CARBON ALLOCATION, PRIMARY PRODUCTION, MYCORRHIZAL PRODUCTION, AND THE ROLES OF THESE RESPONSES IN SOIL CARBON DYNAMICS IN A MIXED HARDWOOD FOREST IN NORTHERN NEW YORK.SPECIFICALLY, WE WILL MEASURE WOOD GROWTH AND LEAF LITTERFALL PRODUCTION; FINE ROOT PRODUCTION, TURNOVER, AND BIOMASS; AND MYCORRHIZAL PRODUCTION AT WOODS LAKE IN ADIRONDACK PARK, NY, WHERE LIME WAS APPLIED TO TWO SUBCATCHMENTS, PAIRED WITH TWO UNTREATED SUBCATCHMENTS, OVER 30 YEARS AGO. THESE MEASUREMENTS WILL PROVIDE INSIGHTS INTO HOW TREE CARBON ALLOCATION AND PRODUCTIVITY RESPOND TO CALCIUM ADDITION OVER THE LONG TERM, AND WILL SHED LIGHT ONTO THE FACTORS DRIVING EXTRAORDINARY FOREST FLOOR CARBON ACCUMULATION THAT HAS OCCURRED WHERE LIME WAS APPLIED. OVERALL, THE PROPOSED RESEARCH WILL CONTRIBUTE TO OUR BASIC UNDERSTANDING OF FACTORS GOVERNING PRIMARY PRODUCTION, ABOVEGROUND-BELOWGROUND CARBON ALLOCATION, AND SOIL CARBON STORAGE IN FORESTS. THE KNOWLEDGE GAINED FROM THIS RESEARCH CAN BE USED TO IMPROVE PREDICTIVE CARBON MODELING EFFORTS, AND TO INFORM MANAGEMENT DECISIONS INCLUDING SUSTAINING FOREST PRODUCTIVITY, ENHANCING FOREST CARBON UPTAKE AND STORAGE, AND MAINTAIN AND IMPROVING SOIL HEALTH.