Avicennia marina: Growth, Allometry and Carbon Potential

Updated 2026-11-02 · 4 min read · By the akar.earth specialist team

Avicennia marina (api-api) carbon sequestration: pioneer mangrove ecology, wood density, mangrove allometry, blue carbon role and restoration risks.

Avicennia marina sequesters carbon as a pioneer mangrove that colonises new mudflats and builds soil, so its biggest carbon contribution is often the sediment and soil carbon that accumulates under it. It also tolerates more salt and harsher conditions than most mangroves, which makes it valuable where other species fail.

Identity and range

Avicennia marina is a true mangrove now placed in the family Acanthaceae (formerly Avicenniaceae or Verbenaceae). In Indonesia it is called api-api or api-api putih. In English it is the grey or white mangrove. Indonesia also has A. alba and A. officinalis, also called api-api, so confirm species identification in the field.

A. marina has one of the widest ranges of any mangrove, from East Africa and the Red Sea through Asia to Australia and New Zealand. In Indonesia it occurs along most coasts with mangroves, including the north coast of Java, Bali, Nusa Tenggara, Sulawesi and Papua. It is common in drier and more saline settings, such as parts of East Nusa Tenggara and Bali.

Growth habit and rotation

A. marina ranges from a shrub to a tree of 10 m or more, with pale grey bark and leaves that excrete salt from their surfaces. It produces dense, pencil-like pneumatophores (breathing roots) that rise from shallow cable roots. These trap sediment and help raise the soil surface.

It is a pioneer on the seaward fringe and on newly accreting mud, and it tolerates high salinity and periodic drought. Its propagules are smaller than those of Rhizophora and germinate quickly after falling. Natural recruitment is often strong where tidal flow is restored. It is not usually managed on a harvest rotation, though it is cut locally for fuelwood and fodder. Reported growth rates vary widely with salinity, tide and climate.

Wood density and biomass estimation

Reported basic density for A. marina is roughly 0.60 to 0.75 g/cm³. Wood density varies with site and age.

Common approaches:

• Komiyama et al. 2005 common mangrove equation, based on DBH and wood density, with a companion root equation. It is widely used for mixed mangrove stands.
• Species-specific Avicennia equations, published from Asia, Australia and other regions. Choose one whose size range and growth form match yours, because A. marina ranges from shrubby to tree form.
• Chave et al. 2014: AGB (kg) = 0.0673 × (ρ × D² × H)^0.976.

Multi-stemmed shrubby trees need each stem measured. See our allometric equations guide.

Convert to carbon with a carbon fraction (IPCC default 0.47, or mangrove values in the IPCC Wetlands Supplement) and to CO2 with 44/12.

Carbon role in blue carbon projects

• Natural regeneration. Restoring tidal flow to abandoned ponds often lets Avicennia recruit naturally. This is the core idea behind ecological mangrove restoration. See aquaculture pond rehabilitation.
• Soil building. Sediment trapping raises the soil surface and builds organic carbon. See mangrove soil carbon.
• Crediting. Projects claiming soil and biomass carbon usually use Verra’s VM0033. See mangrove restoration carbon and the blue carbon hub.

Co-benefits and livelihoods

A. marina protects eroding shorelines and pond banks, supports fisheries and shellfish, and provides fodder and fuelwood. Its flowers support honey production in some areas.

Risks and cautions

• Overlooked in planting. Projects focused on Rhizophora often ignore Avicennia, even where it would grow better. Match species to zone.
• Small trees. Carbon per tree is lower than for Rhizophora. Model soil carbon carefully rather than inflating biomass.
• Cutting and grazing. Local fuelwood and fodder use can reduce stocks.
• Conversion and erosion. Ponds, reclamation and coastal works destroy fringe stands.
• Sea-level rise. Fringe stands are first to drown if sediment supply falls.

Planning notes for project developers

• Survey before planting. Check elevation relative to tide levels, and look for natural Avicennia seedlings. Where they already recruit, planting may be unnecessary.
• Measure soil carbon properly. Most of the credit potential sits in soil, so plan cores to the depth your methodology requires and measure bulk density.
• Mixed-species monitoring. In natural regeneration, several mangrove species appear. Identify each tree and apply the right wood density.
• Map with remote sensing. Fringe mangroves change fast. Repeat imagery helps document gains and erosion losses; see remote sensing for biomass.

Worked example

An A. marina with DBH 15 cm, height 8 m and density 0.65 g/cm³, using Chave et al. 2014:

1. ρ × D² × H = 0.65 × 225 × 8 = 1,170
2. AGB = 0.0673 × 1,170^0.976 ≈ 66 kg
3. Carbon = 66 × 0.47 ≈ 31 kg C
4. CO2e = 31 × 44/12 ≈ 114 kg CO2e (above-ground only)

Compare with the Komiyama common equation in your model and test values in the tree CO2 calculator.