查看文章

Mangroves have the capacity to sequester organic carbon (C_org) in their sediments permanently. However, the carbon budget of mangroves is also affected by the total alkalinity (TA) budget. Principally, TA emitted from carbonate sediment dissolution is a perennial sink of atmospheric CO₂. The assessment of the TA budget of mangrove carbonate sediments in the Red Sea revealed a large TA emission of 403 ± 17 mmol m⁻² d⁻¹, independent of light, seasons, or the presence of pneumatophores, compared to −36 ± 10 mmol m⁻² d⁻¹ in lagoon sediment. We estimate the TA emission from carbonate dissolution in Red Sea mangroves supported a CO₂ uptake of 345 ± 15 gC m⁻² yr⁻¹, 23‐fold the C_org burial rate of 15 gC m⁻² yr⁻¹. The focus on C_org burial in sediments may substantially underestimate the role of mangroves in CO₂ removal. Quantifying the role of mangroves in climate change …