# Dipterocarp forests Vietnam, mixed-species AGB from D, H and wood density (M4, Eq. 17)

Aboveground biomass equation for Mixed species, dipterocarp forest (26 species), Vietnam, from Huy et al. 2016. 222 trees, DBH 3.4–48.8 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Huy et al. 2016 (Eq. 17, p. 9):

> AGB = 0.06203 × DBH2.26430 × H0.51415 × WD0.79456

Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#equation

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

```
Aboveground biomass = 0.06203 * D^2.2643 * H^0.51415 * rho^0.79456
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m); rho = Wood density (oven-dry mass / green volume) (g/cm³).
The source's own form: 0.06203 * DBH^2.26430 * H^0.51415 * WD^0.79456, with DBH in cm, H in m, WD in g/cm3; output in kg.
Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Mixed species, dipterocarp forest (26 species) (mixed species); broadleaf
- Where: Dipterocarp forests, Central Highlands and Southeast ecoregions, Vietnam. Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 222. Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#n_trees
- DBH range: 3.4–48.8 cm. Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#dbh
- Height range: 2.5–23.5 m. Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#height
- Method: nonlinear weighted least squares (power variance function). Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#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

Huy, B., Poudel, K. P., Kralicek, K., Hung, N. D., Khoa, P. V., Phuong, V. T., & Temesgen, H. (2016). Allometric Equations for Estimating Tree Aboveground Biomass in Tropical Dipterocarp Forests of Vietnam. Forests, 7(8), 180.

- DOI: https://doi.org/10.3390/f7080180
- Access: open access
- Copy we read: https://www.mdpi.com/1999-4907/7/8/180/htm
- Every equation from this source: https://treeallometry.org/sources/huy-2016/
- Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#source

## The facts, in the source's words

**Equation** (Eq. 17, p. 9):

> AGB = 0.06203 × DBH2.26430 × H0.51415 × WD0.79456

Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#equation

**Trees measured** (Section 2.2):

> A total of 222 trees were destructively sampled

Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#quote-fit-n-trees

**Smallest DBH** (Table 2):

> Min 3.4 / Max 48.8 (DBH, Mixed-Species)

Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#quote-fit-dbh-min-cm

**Our note:** AGB is the sum of stem, branch and foliage dry mass. Fitted on the whole dataset with the fixed-effects model; the random ecoregion effect was not retained. No correction factor is stated. Recommended by the authors for mixed species when H and WD are available.

## 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, H = 8, rho = 0.55 | 20.7 | 20.7 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 20, H = 14, rho = 0.65 | 151 | 151 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 40, H = 20, rho = 0.75 | 977 | 977 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/huy-2016-m4-d-h-rho/#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: Huy, B., Poudel, K. P., Kralicek, K., Hung, N. D., Khoa, P. V., Phuong, V. T., & Temesgen, H. (2016). Allometric Equations for Estimating Tree Aboveground Biomass in Tropical Dipterocarp Forests of Vietnam. Forests, 7(8), 180. https://doi.org/10.3390/f7080180

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Dipterocarp forests Vietnam, mixed-species AGB from D, H and wood density (M4, Eq. 17)", checked 2026-11-02, https://treeallometry.org/equations/huy-2016-m4-d-h-rho/. 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/huy-2016-m4-d-h-rho.json
Report a problem: email info@restorationscope.com with the equation id (huy-2016-m4-d-h-rho) and where the right value appears.