Spatial and landscape-scale variability in global mangrove soil carbon estimates

Accurate global mangrove soil carbon estimates are essential, considering the critical role mangroves play in the coastal carbon cycle. However, current global estimates vary widely, ranging from 2.26 to 10.2 Pg C. Large uncertainties in carbon stocks can be challenging for effective policymaking and inaccurately estimate climate mitigation potential. Here, we identify factors driving spatial and landscape variability by comparing five global mangrove soil carbon stock models. Using the ensemble mean, we generate a global soil carbon stock estimate of 4.13 ± 0.89 Pg C (to 1 m depth). Significant (P < 0.001) spatial variability occurred in Africa and Asia, with high standard deviation between models and limited data representation. High standard deviation occurred in specific geomorphic settings, including terrigenous, deltaic, carbonate and open coasts, within microtidal sites and regions of low and high species diversity. Our findings can help guide future research and reduce uncertainties in carbon stock estimates.