Abstract

A long history of ecological research in vegetated coastal ecosystems supports the blue carbon concept, which refers to the carbon stored in mangroves, salt marshes, and seagrass meadows. The combination of high plant productivity, slow decomposition, sediment accumulation, and unique soil characteristics makes these ecosystems efficient carbon sinks. Under the current climate change scenario, their importance has grown significantly, becoming central to several climate policies at both local and global scales and a key component in implementing natural climate solutions. Yet, global blue carbon accounting is incomplete, with major gaps in southern hemisphere data. It also shows large variability, suggesting that the interaction between environmental and biological drivers is important at the local scale. In this seminar, I will present our findings exploring the biological and environmental factors that determine blue carbon stocks in the southwest Atlantic salt marshes. We identify that the impact of burrowing crabs, along with the identity of the dominant plant species, accretion rates, and granulometry, are the main factors in determining organic carbon stocks. These results help fill a major gap in blue carbon data for southern hemisphere salt marshes and contribute to understanding the ecological mechanisms behind them.