# Acacia mangium (2nd generation) plantation, Sarawak, AGB from D (power)

Aboveground biomass equation for Acacia mangium, Malaysia, from Adam & Jusoh 2018. 35 trees, DBH 11.6–41.5 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Adam & Jusoh 2018 (Table 2, model 2):

> y = 0.1173D2.454

Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#equation

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

```
Aboveground biomass = 0.1173 * D^2.454
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 0.1173 * DBH^2.454, with DBH in cm; output in kg.
Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Acacia mangium (species), family Fabaceae; broadleaf
- Where: Daiken Sarawak plantation, Bintulu district, Sarawak. Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#where
- Biomes: tropical
- Stand: plantation
- Trees measured: 35. Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#n_trees
- DBH range: 11.6–41.5 cm. Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#dbh
- R²: 0.94. Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#r2
- Method: power regression of dry AGB on DBH. Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#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

Adam, N. S., & Jusoh, I. (2018). Allometric model for predicting aboveground biomass and carbon stock of Acacia plantations in Sarawak, Malaysia. BioResources, 13(4), 7381-7394.

- DOI: https://doi.org/10.15376/biores.13.4.7381-7394
- Access: open access
- Copy we read: https://bioresources.cnr.ncsu.edu/wp-content/uploads/2018/08/BioRes_13_4_7381_Adam_Jusoh_Allometric_Model_Biomass_Aboveground_Carbon_Stock_Acacia_14078.pdf
- Every equation from this source: https://treeallometry.org/sources/adam-2018/
- Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#source

## The facts, in the source's words

**Equation** (Table 2, model 2):

> y = 0.1173D2.454

Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#equation

**Trees measured** (Field Sampling):

> Thirty five trees of second generation A. mangium

Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#quote-fit-n-trees

**Smallest DBH** (Results and Discussion, Aboveground Biomass Models):

> The DBH of felled Acacia hybrid and second generation A. mangium ranged from 12.8 to 40.9 cm and 11.6 to 41.5 cm, respectively

Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#quote-fit-dbh-min-cm

**Our note:** About 10-year-old stand. AGB is the sum of stem, branch and leaf dry mass. The paper also prints linear, exponential and logarithmic fits (Table 2) but rejects them (negative predictions for small trees); only the power model, which the authors select, is included.

## 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 = 15 | 90.2 | 90.2 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 25 | 316 | 316 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 40 | 1,002 | 1,002 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/adam-2018-mangium-power/#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: Adam, N. S., & Jusoh, I. (2018). Allometric model for predicting aboveground biomass and carbon stock of Acacia plantations in Sarawak, Malaysia. BioResources, 13(4), 7381-7394. https://doi.org/10.15376/biores.13.4.7381-7394

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Acacia mangium (2nd generation) plantation, Sarawak, AGB from D (power)", checked 2026-11-02, https://treeallometry.org/equations/adam-2018-mangium-power/. 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/adam-2018-mangium-power.json
Report a problem: email info@restorationscope.com with the equation id (adam-2018-mangium-power) and where the right value appears.