Carbon sequestration in mangrove forests

Background

Mangrove forests are highly valuable due to the ecological (e.g., sediment deposition, fish nurseries, protection from tropical storms) and economic (e.g., food, fuel) resources they provide. Carbon storage potential in mangroves is also a highly valuable characteristic, especially as a passive method of carbon dioxide capture and storage. In order to protect these important resources and services, it is necessary to create accurate analyses of the global potential and significance of carbon storage in mangroves.

Goals and Methods

This study analyzes the global significance of mangroves as a method of carbon sequestration by reviewing available literature on carbon production, carbon storage, sediment accumulation mechanisms, and soil accretion rates.

Conclusions and Takeaways

Mangrove forests could be significant carbon sinks for up to a century if left undisturbed, due to their rapid carbon production, aboveground and belowground biomass stores, stable maturity, and large pools of soil carbon that increase with age. Mangrove roots and vegetation actively facilitate silt, clay, and organic matter settlement, generating an average soil accretion rate of 5 mm per year that allows most mangroves to keep pace with sea level rise. Despite these carbon storage properties, mangrove forests only sequester about 13.53 Gt of carbon per year globally, due to their small areal extent, whereas other terrestrial forests sequester around 330 to 450 Gt of carbon per year globally. However, there is a high potential for significant greenhouse gas emissions from mangrove forest loss or disturbance, so it is still important to incorporate the conservation and restoration of mangroves into climate change mitigation strategies, like blue carbon projects and REDD+.