Application of structural equation modelling to study complex "blue carbon" cycling in mangrove ecosystems.

Blue carbon cycling in mangrove ecosystems is proving to be more complex than previously thought. The objective of this study was the application of structural equation modelling (SEM) to capture such complex and varying data types and provide a holistic understanding of mangrove blue carbon cycling using data from the Indian Sundarban as a test case. We found that SEM was effective at integrating multiple data types and characterizing the processes and variables that regulate the nature and magnitude of CO2 fluxes within a mangrove ecosystem, including atmosphere-hydrosphere, atmosphere-pedosphere, and net ecosystem exchange. Overall, this study finds that atmospheric, water, and soil temperatures were the main and common drivers of CO2 effluxes towards the atmosphere from the entire ecosystem, waterbodies, and soils of mangrove ecosystems, respectively. We conclude that SEM is useful for combining data from different sources, gaining an overarching view of the complex biogeochemical cycling of the blue carbon ecosystems.