# Sonneratia apetala stem biomass, a x^b of DBH^2 * H (Table 4)

Stem biomass equation for Sonneratia apetala, Myanmar (Burma), from Lwin et al. 2026. 15 trees, DBH 5.1–20 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Lwin et al. 2026 (Table 4):

> Stem (kg) DBH2H (cm2, m) 15 0.0125 (±0.0411×10−1) 1.046 (±0.0506) 0.970*

Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#equation

In this library's units, ready to compute (stem biomass in kg):

```
Stem biomass = 0.0125 * (D^2 * H)^1.046
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: 0.0125 * (DBH^2 * H)^1.046, with DBH in cm, H in m; output in kg.
Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#canonical

## What it covers

- Output: Stem biomass, kg
- Taxon: Sonneratia apetala (species), family Lythraceae; mangrove
- Where: Letkhokkon delta mangrove, Myanmar. Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#where
- Biomes: tropical, mangrove
- Stand: natural
- Trees measured: 15. Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#n_trees
- DBH range: 5.1–20 cm. Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#dbh
- Height range: 4.6–13.6 m. Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#height
- R²: 0.97. Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#r2
- Method: Power function y = a x^b fitted in SPSS Curve Estimation (OLS on log-transformed variables, then back-transformed). Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#checked_at

A missing fit statistic is one the source doesn't state, or that we haven't recorded; it is never estimated. Outside the stated DBH range or region, the equation is an extrapolation.

## Source

Lwin, K.M., Hien, C.T.T., Chan, N. (2026). Establishment of site- and species-specific allometric models of the dominant mangrove species and estimation of mangrove biomass in Letkhokkon Area, Myanmar. TROPICS, 35(1), 39–53.

- DOI: https://doi.org/10.3759/tropics.simm01
- Access: open access
- Copy we read: https://www.jstage.jst.go.jp/article/tropics/35/1/35_SIMM01/_pdf/-char/en
- Every equation from this source: https://treeallometry.org/sources/lwin-2026/
- Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#source

## The facts, in the source's words

**Equation** (Table 4):

> Stem (kg) DBH2H (cm2, m) 15 0.0125 (±0.0411×10−1) 1.046 (±0.0506) 0.970*

Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#equation

**Trees measured** (Table 2):

> Sa 15 5.1 20 4.6 13.6

Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#quote-fit-n-trees

**Smallest DBH** (Biomass measurement section):

> The S. apetala had a DBH range of 5.1 cm to 20.0 cm and a H range of 4.6 m to 13.6 m

Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#quote-fit-dbh-min-cm

**Our note:** Power-law fit; the paper states coefficients are back-transformed from the log-log OLS fit and prints no correction factor, so none is applied. Site-level model for the Letkhokkon delta mangrove (Ayeyarwady delta region), Myanmar.

## Checks this equation passes

On every build, the library's form and the source's own form (in its units) must both give these values within 1%.

| Inputs | Expected | We get | From |
| --- | --- | --- | --- |
| D = 8, H = 6 | 6.31 | 6.31 | Computed from the printed form: computed from the Table 4 coefficients |
| D = 15, H = 9 | 35.9 | 35.9 | Computed from the printed form: computed from the Table 4 coefficients |

Cite: https://treeallometry.org/equations/lwin-2026-sa-stem/#checks

The calculator on the page shows carbon as biomass × 0.47 (IPCC 2006 Guidelines, Vol. 4, Ch. 4, Table 4.3) and CO₂e as carbon × 44/12.

## How to cite

Cite the source for the equation: Lwin, K.M., Hien, C.T.T., Chan, N. (2026). Establishment of site- and species-specific allometric models of the dominant mangrove species and estimation of mangrove biomass in Letkhokkon Area, Myanmar. TROPICS, 35(1), 39–53. https://doi.org/10.3759/tropics.simm01

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Sonneratia apetala stem biomass, a x^b of DBH^2 * H (Table 4)", checked 2026-11-02, https://treeallometry.org/equations/lwin-2026-sa-stem/. Data CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Quotes are the authors' words.

Data for this equation: https://treeallometry.org/data/equations/lwin-2026-sa-stem.json
Report a problem: email info@restorationscope.com with the equation id (lwin-2026-sa-stem) and where the right value appears.