Sonneratia alba: Growth, Allometry and Carbon Potential

Updated 2026-11-02 · 3 min read · By the akar.earth specialist team

Sonneratia alba (pedada) carbon sequestration: seaward pioneer ecology, wood density, mangrove allometry, blue carbon role and restoration risks in Indonesia.

Sonneratia alba sequesters carbon on the most exposed seaward edge of mangrove forests, where it stabilises sediment that later supports other species. Its wood is lighter than Rhizophora, but its role as a pioneer that protects the rest of the forest makes it important in blue carbon restoration.

Identity and range

Sonneratia alba is a true mangrove in the family Lythraceae (formerly Sonneratiaceae). In Indonesia it is called pedada or perepat. In English it is the mangrove apple. Indonesia also has S. caseolaris (often in brackish river mouths) and S. ovata; confirm identification, because their zones and growth differ.

S. alba is native from East Africa across South and Southeast Asia to northern Australia and the western Pacific. In Indonesia it is common on the seaward fringe of mangroves throughout the archipelago, including on small islands, sandy coasts and near coral reefs in Sulawesi, Maluku and Papua, such as North Sulawesi and Maluku.

Growth habit and rotation

S. alba is a tree that can reach 15 to 20 m or more, with a spreading crown and thick, cone-shaped pneumatophores that rise from horizontal roots. Its flowers open at night, have many long white stamens and are pollinated by bats and moths. Its fruit is a round, flattened berry.

Unlike Rhizophora and Bruguiera, Sonneratia is not viviparous. It spreads by seeds from its fruit, so restoration usually relies on nursery-raised seedlings or natural recruitment rather than direct propagule planting. It tolerates frequent flooding, wave exposure and high salinity, and colonises sandy and muddy substrates.

It is not usually harvested on a rotation. Reported growth rates vary widely with exposure, sediment and salinity.

Wood density and biomass estimation

S. alba has lighter wood than Rhizophora. Reported basic density values fall roughly between 0.50 and 0.70 g/cm³, varying with site and age. Record your wood density source.

Common approaches:

• Komiyama et al. 2005 common mangrove equation, based on DBH and wood density, plus a companion root equation.
• Species-specific Sonneratia equations from Southeast Asia and elsewhere, where available.
• Chave et al. 2014: AGB (kg) = 0.0673 × (ρ × D² × H)^0.976.

Large pneumatophores can contribute meaningful below-ground and above-ground root biomass. Check whether your equation and methodology account for them. 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

• Seaward protection. Sonneratia and Avicennia fringes reduce wave energy and erosion, protecting inland mangroves and their soil carbon.
• Zonation-based restoration. Planting Sonneratia on exposed seaward sites, where Rhizophora often fails, raises survival. See mangrove restoration carbon and Avicennia marina.
• Soil carbon. Fringe soils accumulate sediment and organic carbon; see mangrove soil carbon.
• Crediting. Restoration claiming soil carbon usually follows Verra’s VM0033.

See the blue carbon hub for project pathways.

Co-benefits and livelihoods

S. alba fruits are eaten and made into drinks and sweets in some coastal communities. Its flowers support bats and insects. Fringe stands protect shorelines, fisheries and coastal settlements.

Risks and cautions

• Exposure. Seaward sites have high wave energy. Seedlings may need temporary protection, and some sites are simply too exposed.
• Nursery dependence. No propagules means more nursery work and cost. See nursery and survival rates.
• Erosion and sea-level rise. Fringe stands are first to be lost when sediment supply falls.
• Coastal works. Reclamation, ports and sea walls remove fringe mangroves.
• Misidentification. Mixing up S. alba and S. caseolaris leads to planting in the wrong salinity zone.

Planning notes for project developers

• Use nursery seedlings. Raise seedlings from fruit in nurseries near the site and plant at a size that withstands waves.
• Temporary wave protection. Bamboo or brushwood barriers can shelter seedlings on exposed sites until roots establish.
• Check identification. Confirm S. alba versus S. caseolaris before collecting seed.

Worked example

An S. alba with DBH 20 cm, height 12 m and density 0.55 g/cm³, using Chave et al. 2014:

1. ρ × D² × H = 0.55 × 400 × 12 = 2,640
2. AGB = 0.0673 × 2,640^0.976 ≈ 147 kg
3. Carbon = 147 × 0.47 ≈ 69 kg C
4. CO2e = 69 × 44/12 ≈ 253 kg CO2e (above-ground only)

Test values in the tree CO2 calculator, and compare with the Komiyama common equation in your own model.