akar.earthMangrove: Definition
What is a mangrove? Why salt-tolerant coastal forests store so much carbon, how mangrove carbon is measured, and Indonesia's restoration opportunity.
A mangrove is a salt-tolerant tree or shrub that grows in the intertidal zone of tropical and subtropical coasts, and the term also refers to the forests these plants form. Mangrove forests are one of the main blue carbon ecosystems, storing large amounts of carbon in their roots and waterlogged soils.
Why it matters
Mangroves hold far more carbon per hectare than many inland forests, mostly in sediments that build up over centuries. Clearing them, often for shrimp ponds, releases that carbon. Mangroves also protect coasts from storms and erosion, support fisheries and supply wood and food. Restoration and conservation projects can earn carbon credits and deliver strong co-benefits.
How mangrove carbon is measured
- Biomass: mangrove-specific allometric equations for genera such as Rhizophora, Avicennia, Bruguiera and Sonneratia, with DBH measured above stilt roots.
- Roots: below-ground biomass is large and needs specific ratios or equations.
- Soil: cores to 1 m or deeper, with bulk density and carbon content measured.
- Survival and zoning: planted seedlings must match tidal elevation and salinity.
Verra’s VM0033 covers tidal wetland restoration. See our guides to mangrove restoration carbon and mangrove soil carbon.
Indonesia angle
Indonesia has the largest mangrove area of any country, across Papua, Kalimantan, Sumatra, Sulawesi and many smaller islands. Large areas were lost to aquaculture, and many ponds are now abandoned and suitable for hydrological restoration. National policy prioritises mangrove rehabilitation. Common restoration species include Rhizophora mucronata, Rhizophora apiculata and Avicennia marina. Tenure on coastal land often involves forestry, marine and local authorities, so clarify rights early.
Common mistakes
- Planting single species in rows on mudflats where mangroves never grew.
- Ignoring hydrology; restoring tidal flow often matters more than planting.
- Using terrestrial allometry or ignoring soil carbon.
Related terms
See blue carbon, seagrass and WRC, or explore the blue carbon hub.
Frequently asked questions
How much carbon do mangroves store?
Mangroves store high amounts of carbon per hectare, with most in their deep, waterlogged soils. Values vary widely by site, so projects measure soil cores rather than rely on a single figure.
Can mangrove planting earn carbon credits?
Yes, if it meets methodology rules, such as Verra VM0033, including land eligibility, additionality and monitoring of both biomass and soil carbon.