# Lowland Dipterocarp forest, mixed species, DBH and wood density

Aboveground biomass equation for Mixed species of lowland Dipterocarp forest, Indonesia, from Basuki et al. 2009. 122 trees, DBH 6–200 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Basuki et al. 2009 (Table 1):

> ln(TAGB) = c + αln(DBH) + βln(WD) c −0.744 ... α 2.188 ... β 0.832 ... 0.970 0.303 26.51 1.047

Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#equation

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

```
Aboveground biomass = 1.047 * exp(-0.744 + 2.188 * ln(D) + 0.832 * ln(rho))
```

Inputs: D = Diameter at breast height (1.3 m) (cm); rho = Wood density (oven-dry mass / green volume) (g/cm³).
The source's own form: 1.047 * exp(-0.744 + 2.188 * ln(DBH) + 0.832 * ln(WD)), with DBH in cm, WD in g/cm3; output in kg.
Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Mixed species of lowland Dipterocarp forest (mixed species); broadleaf
- Where: Lowland mixed Dipterocarp forest, East Kalimantan, Indonesia. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 122. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#n_trees
- DBH range: 6–200 cm. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#dbh
- R²: 0.97. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#r2
- Residual SE: 0.303. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#rse
- Correction factor: 1.047 (applied). Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#cf
- Method: OLS on ln-transformed data, adjusted r2. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-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

Basuki, T.M., van Laake, P.E., Skidmore, A.K., Hussin, Y.A. (2009). Allometric equations for estimating the above-ground biomass in tropical lowland Dipterocarp forests. Forest Ecology and Management, 257(8), 1684–1694.

- DOI: https://doi.org/10.1016/j.foreco.2009.01.027
- Access: open access
- Copy we read: https://ris.utwente.nl/ws/files/305501505/1_s2.0_S0378112709000516_main.pdf
- Every equation from this source: https://treeallometry.org/sources/basuki-2009/
- Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#source

## The facts, in the source's words

**Equation** (Table 1):

> ln(TAGB) = c + αln(DBH) + βln(WD) c −0.744 ... α 2.188 ... β 0.832 ... 0.970 0.303 26.51 1.047

Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#equation

**Where** (Abstract):

> The data were collected in lowland mixed Dipterocarp forests in East Kalimantan, Indonesia.

Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#quote-region

**Units** (Table 1 note):

> TAGB; total above-ground biomass based on dry weight (kg/tree), DBH: diameter at breast height (cm)

Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-rho/#quote-published-units

**Our note:** ln-ln OLS; the authors back-transform with the correction factor (CF) listed in Table 1, which is applied here. Intercepts are negative in the printed table (checked on the rendered page; text extraction drops the sign). DBH measured at 1.30 m or above buttresses.

## 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 = 30, rho = 0.6 | 555 | 555 | Computed from the printed form: hand-computed from the published form |
| D = 80, rho = 0.6 | 4,745 | 4,745 | Computed from the printed form: hand-computed from the published form |

Cite: https://treeallometry.org/equations/basuki-2009-mixed-d-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: Basuki, T.M., van Laake, P.E., Skidmore, A.K., Hussin, Y.A. (2009). Allometric equations for estimating the above-ground biomass in tropical lowland Dipterocarp forests. Forest Ecology and Management, 257(8), 1684–1694. https://doi.org/10.1016/j.foreco.2009.01.027

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Lowland Dipterocarp forest, mixed species, DBH and wood density", checked 2026-11-01, https://treeallometry.org/equations/basuki-2009-mixed-d-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/basuki-2009-mixed-d-rho.json
Report a problem: email info@restorationscope.com with the equation id (basuki-2009-mixed-d-rho) and where the right value appears.