ERC advanced grant to Sue Trumbore on terrestrial carbon cycling

(Picture by: Sven Doering)
The overall goal of Sue Trumbore’s newly granted ERC project “14Constraint” is to enhance the availability and use of radiocarbon data as constraints for process-based understanding of the age distribution of carbon in and respired by soils and ecosystems.
Carbon enters ecosystems by a single process, photosynthesis. It returns by a range of processes that depend on plant allocation and turnover, the efficiency and rate of litter decomposition and the mechanisms stabilizing C in soils. Thus the age distribution of respired CO2 and the age of C residing in plants, litter and soils are diagnostic properties of ecosystems that provide key constraints for testing carbon cycle models. Radiocarbon, especially the transit of ‘bomb’ 14C created in the 1960s, is a powerful tool for tracing C exchange on decadal to centennial timescales. 14Constraint will assemble a global database of existing radiocarbon data and demonstrate how they can constrain and test ecosystem carbon cycle models. The project will furthermore fill data gaps and add new data from sites in key biomes that have ancillary data sufficient to construct belowground C and 14C budgets. Overall, this project is urgently needed before atmospheric 14C levels decline to below 1950 levels as expected in the next decade.