COASTAL WETLANDS STORE DISPROPORTIONATELY LARGE AMOUNTS OF CARBON DUE TO HIGH RATES OF NET PRIMARY PRODUCTIVITY AND SLOW MICROBIAL DEGRADATION OF ORGANIC MATTER IN WATER-SATURATED SOILS. WIDE SPATIAL AND TEMPORAL VARIABILITY IN PLANT COMMUNITIES AND SOIL BIOGEOCHEMISTRY NECESSITATE LOCATION-SPECIFIC QUANTIFICATION OF CARBON STOCKS TO IMPROVE CURRENT WETLAND CARBON INVENTORIES AND FUTURE PROJECTIONS. WE WILL USE FIELD MEASUREMENTS, REMOTE SENSING TECHNOLOGY, AND SPATIOTEMPORAL MODELS TO QUANTIFY REGIONAL CARBON STORAGE AND MODEL FUTURE SPATIAL VARIABILITY OF CARBON STOCKS IN MANGROVES AND COASTAL MARSHES IN SOUTHWEST FLORIDA. WE WILL EXAMINE CARBON ACCUMULATION AND ACCRETION RATES ON TIME SCALES RANGING FROM DECADAL TO MILLENNIAL TO PROJECT RESPONSES TO CLIMATE CHANGE, INCLUDING SEA-LEVEL RISE AND CLIMATE-DRIVEN HABITAT SWITCHING (MARSH TO MANGROVE CONVERSION), AS WELL AS INVESTIGATE THE INFLUENCE OF SOIL MICROBIAL COMMUNITIES AND VEGETATION TYPE ON THE TRANSLOCATION OF NEW LITTER MATERIAL INTO THE SOIL C POOL. THE STUDY REGION WILL INCLUDE A GRADIENT OF URBANIZATION AND VEGETATION TYPES (FROM NORTH TO SOUTH): TAMPA BAY (HIGHLY URBANIZED), CHARLOTTE HARBOR (VARIABLE URBANIZATION), TEN THOUSAND ISLANDS AND EVERGLADES NATIONAL PARK (UNDEVELOPED), ALL OF WHICH SHOW EVIDENCE OF HABITAT SWITCHING FROM MARSH TO MANGROVE-DOMINATED WETLANDS, WHICH IS EXPECTED TO CONTINUE WITH FURTHER WARMING.