# Planted Acacia mangium, West Java, branch biomass from D, all ages (model B)

Branch biomass equation for Acacia mangium, Indonesia, from Miyakuni et al. 2004. 59 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Miyakuni et al. 2004 (Table 3, model B, stand age 3-10):

> Y = a·dbh^b; a = 0.0046, b = 2.8669, r2 = 0.9359

Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#equation

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

```
Branch biomass = 0.0046 * D^2.8669
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 0.0046 * dbh^2.8669, with dbh in cm; output in kg.
Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#canonical

## What it covers

- Output: Branch biomass, kg
- Taxon: Acacia mangium (species), family Fabaceae; broadleaf
- Where: Maribaya and Tenjo ranger districts (Parungpanjang), Perhutani, West Java. Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#where
- Biomes: tropical
- Stand: plantation
- Trees measured: 59. Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#n_trees
- R²: 0.9359. Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#r2
- Method: log-linear least squares of Y = a·dbh^b. Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#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

Miyakuni, K., Heriansyah, I., Heriyanto, N. M., & Kiyono, Y. (2004). Allometric Biomass Equations, Biomass Expansion Factors and Root-to-shoot Ratios of Planted Acacia mangium Willd. Forests in West Java, Indonesia. Journal of Forest Planning, 10(2), 69-76.

- DOI: https://doi.org/10.20659/jfp.10.2_69
- Access: open access
- Copy we read: https://www.jstage.jst.go.jp/article/jfp/10/2/10_KJ00007911299/_pdf
- Every equation from this source: https://treeallometry.org/sources/miyakuni-2004/
- Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#source

## The facts, in the source's words

**Equation** (Table 3, model B, stand age 3-10):

> Y = a·dbh^b; a = 0.0046, b = 2.8669, r2 = 0.9359

Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#equation

**Trees measured** (Destructive Sampling to Measure the Biomass of Individual Trees, p. 72):

> We selected 15 trees from the 3-year-old stand, 12 trees from the 5-year-old stand, 16 trees from the 8-year-old stand, and 16 trees from the 10-year-old stand

Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#quote-fit-n-trees

**Our note:** Model B (the authors' recommended general equation): all four stand ages combined (3-10 yr). Fitted in log space (log-linear) and printed as a power law; the paper states no back-transformation correction factor and none is applied. The paper does not print the sampled dbh range. Branch biomass (Yb) includes dead branches still attached to the tree, as defined by the authors (p. 72).

## 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 = 5 | 0.464 | 0.464 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 10 | 3.39 | 3.39 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 20 | 24.7 | 24.7 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/#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: Miyakuni, K., Heriansyah, I., Heriyanto, N. M., & Kiyono, Y. (2004). Allometric Biomass Equations, Biomass Expansion Factors and Root-to-shoot Ratios of Planted Acacia mangium Willd. Forests in West Java, Indonesia. Journal of Forest Planning, 10(2), 69-76. https://doi.org/10.20659/jfp.10.2_69

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Planted Acacia mangium, West Java, branch biomass from D, all ages (model B)", checked 2026-11-02, https://treeallometry.org/equations/miyakuni-2004-branch-b-all-ages/. 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/miyakuni-2004-branch-b-all-ages.json
Report a problem: email info@restorationscope.com with the equation id (miyakuni-2004-branch-b-all-ages) and where the right value appears.