How mangroves store carbon in their soil
Waterlogged mud keeps dead roots and leaves from rotting, so mangrove soils hold most of the ecosystem's carbon.
A mangrove forest stores carbon in three places: the living trees, the dead wood and litter, and the soil. In most mangroves the soil holds the largest share, often more than half and sometimes more than three-quarters.
Why the soil is so rich
- Tides keep the mud waterlogged, so there is little oxygen.
- Without oxygen, the microbes that normally rot dead roots and leaves work very slowly.
- Roots and fallen leaves pile up as peat-like soil that can be metres deep.
- Tidal water also brings in sediment carrying carbon from rivers and the sea, which is trapped by the roots.
Orders of magnitude. Studies of mangroves worldwide report whole-ecosystem stocks averaging around 1,000 tonnes of carbon per hectare, with a very wide range from a few hundred to well over 2,000 depending on soil depth and the place. Atlas uses 400 / 700 / 1,000 tC/ha as an illustrative low / central / high bracket so results are conservative.
Why it matters for climate. If the forest is cleared or drained, soil carbon is exposed to air and can be released as CO₂ over years. A hectare of lost mangrove can therefore release far more carbon than a hectare of lost upland forest.
Related reading
More in Knowledge Base
- LAPSSET: why a corridor project matters to mangroves
- Seagrass meadows: blue carbon's quiet partner
- Mangroves in Africa: the big picture
- Sea-level rise and the "coastal squeeze"
- How satellites see mangroves
- Mangrove zonation: why different species grow in bands
- How to read a hot-spot map
- What mangroves do for people (ecosystem services)
Still have a question?
The AI analyst answers from these articles and from the data.
Ask Atlas