# Mixed mangrove stem biomass, power model (D)

Stem biomass equation for Seven mangrove species (Bruguiera cylindrica, B. parviflora, B. sexangula, Ceriops tagal, Rhizophora apiculata, R. mucronata, Xylocarpus granatum), Malaysia, from Abdul-Hamid et al. 2022. 15 trees, DBH 9–33 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Abdul-Hamid et al. 2022 (Table 2):

> (a) M of stem 0.1761D2.3769 0.9223

Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#equation

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

```
Stem biomass = 0.1761 * D^2.3769
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 0.1761 * D^2.3769, with D in cm; output in kg.
Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#canonical

## What it covers

- Output: Stem biomass, kg
- Taxon: Seven mangrove species (Bruguiera cylindrica, B. parviflora, B. sexangula, Ceriops tagal, Rhizophora apiculata, R. mucronata, Xylocarpus granatum) (mixed species); mangrove
- Where: Sungai Pulai Forest Reserve, Johor. Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#where
- Biomes: tropical, mangrove
- Stand: natural
- Trees measured: 15. Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#n_trees
- DBH range: 9–33 cm. Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#dbh
- R²: 0.9223. Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#r2
- Method: power function (intrinsically linear), SPSS general linear model. Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#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

Abdul-Hamid, H., Mohamad-Ismail, F.-N., Mohamed, J., et al. (2022). Allometric Equation for Aboveground Biomass Estimation of Mixed Mature Mangrove Forest. Forests, 13(2), 325.

- DOI: https://doi.org/10.3390/f13020325
- Access: open access
- Copy we read: https://www.mdpi.com/1999-4907/13/2/325
- Every equation from this source: https://treeallometry.org/sources/abdul-hamid-2022/
- Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#source

## The facts, in the source's words

**Equation** (Table 2):

> (a) M of stem 0.1761D2.3769 0.9223

Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#equation

**Trees measured** (Abstract):

> Destructive sampling was conducted using the selective random sampling method on 15 standing trees.

Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#quote-fit-n-trees

**Smallest DBH** (Section 3.1):

> in the range of DBH from 9.0 cm to 33.0 cm

Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#quote-fit-dbh-min-cm

**R²** (Table 2):

> 0.9223

Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#quote-fit-r2

**Our note:** Table 2, equation 1. Output in kg dry mass (aboveground biomass in kg per Section 2.4). D was measured at about 1.37 m above ground, above the highest stilt root for Rhizophora (Section 2.2).

## 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 = 10 | 41.9 | 41.9 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 20 | 217.9 | 217.9 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 30 | 571.1 | 571.1 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/abdul-hamid-2022-stem-d/#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: Abdul-Hamid, H., Mohamad-Ismail, F.-N., Mohamed, J., et al. (2022). Allometric Equation for Aboveground Biomass Estimation of Mixed Mature Mangrove Forest. Forests, 13(2), 325. https://doi.org/10.3390/f13020325

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Mixed mangrove stem biomass, power model (D)", checked 2026-11-02, https://treeallometry.org/equations/abdul-hamid-2022-stem-d/. 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/abdul-hamid-2022-stem-d.json
Report a problem: email info@restorationscope.com with the equation id (abdul-hamid-2022-stem-d) and where the right value appears.