TERRESTRIAL ECOSYSTEMS IN THE NORTHEASTERN U.S. CURRENTLY STORE CARBON IN PLANTS AND SOILS. WHILE THERE IS GENERAL AGREEMENT ABOUT HOW MUCH CARBON IS RELEASED FROM THE BURNING OF FOSSIL FUELS, THERE IS SOME UNCERTAINTY ABOUT HOW CHANGES IN LAND USE AND AIR POLLUTION, SUCH AS ATMOSPHERIC DEPOSITION AND GROUND-LEVEL OZONE, AFFECT HOW MUCH CARBON IS TAKEN UP DURING PHOTOSYNTHESIS AND STORED IN VEGETATION AND SUBSEQUENTLY IN SOILS. THE GOAL OF OUR RESEARCH IS TO DETERMINE HOW BOTH CHANGES IN LAND-USE AND AIR QUALITY AFFECT THE RATES AND MAGNITUDE OF CARBON CYCLING IN FOREST ECOSYSTEMS OF NEW ENGLAND. WE WILL USE A VARIETY OF APPROACHES TO CONDUCT THIS RESEARCH, INCLUDING (1) MEASUREMENTS OF PLANTS, SOILS, CARBON, NITROGEN, AND OZONE IN FORESTS THAT SPAN AN URBAN TO RURAL GRADIENT, (2) MONITORING OF AIR CHEMISTRY, AND (3) AND MODELING THAT ALLOWS US TO UNDERSTAND HOW BOTH PAST LAND-USE AFFECTS CURRENT-DAY RATES OF CARBON CYCLING AND HOW CHANGES IN LAND-USE AND AIR QUALITY MAY AFFECT CARBONCYCLING IN THE FUTURE. THE ULTIMATE GOAL OF THIS WORK IS TO IMPROVE OUR UNDERSTANDING OF HOW FOREST ECOSYSTEMS FUNCTION AND CYCLE BOTH CARBON AND NITROGEN.