# Common mangrove root weight (Eq. 10)

Root biomass equation for Mangroves (10 species: Rhizophora, Bruguiera, Ceriops, Avicennia, Sonneratia, Xylocarpus), Thailand, Indonesia, from Komiyama et al. 2005. 26 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Komiyama et al. 2005 (Eq. 10, p. 475):

> WR = 0.199ρ^0.899 D^2.22

Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#equation

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

```
Root biomass = 0.199 * rho^0.899 * D^2.22
```

Inputs: rho = Wood density (oven-dry mass / green volume) (g/cm³); D = Diameter at breast height (1.3 m) (cm).
The source's own form: 0.199 * rho^0.899 * D^2.22, with rho in g/cm3, D in cm; output in kg.
Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#canonical

## What it covers

- Output: Root biomass, kg
- Taxon: Mangroves (10 species: Rhizophora, Bruguiera, Ceriops, Avicennia, Sonneratia, Xylocarpus) (mixed species); mangrove
- Where: Mangrove forests of Thailand and Indonesia. Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#where
- Biomes: tropical, mangrove
- Stand: natural
- Trees measured: 26. Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#n_trees
- R²: 0.954. Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#r2
- Residual SE: 0.181. Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#rse
- Correction factor: 1.017 (applied). Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#cf
- Method: log-log regression, CF applied (Table 4). Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#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

Komiyama, A., Poungparn, S., Kato, S. (2005). Common allometric equations for estimating the tree weight of mangroves. Journal of Tropical Ecology, 21(4), 471–477.

- DOI: https://doi.org/10.1017/S0266467405002476
- Access: paywalled
- Copy we read: http://web.archive.org/web/20240413003651id_/https://core.ac.uk/download/pdf/59148776.pdf
- Every equation from this source: https://treeallometry.org/sources/komiyama-2005/
- Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#source

## The facts, in the source's words

**Equation** (Eq. 10, p. 475):

> WR = 0.199ρ^0.899 D^2.22

Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#equation

**Fit** (Table 4 (equation before CF)):

> WR = 0.196ρ^0.899 (D²)^1.11 0.954 0.181 1.017

Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#quote-fit

**Trees measured** (Methods, p. 472):

> Within the 104 tree samples, 26 individual trees were

Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#quote-fit-n-trees

**Our note:** Root weight includes the prop roots of Rhizophora. D = DR0.3 for Rhizophoraceae, dbh otherwise. Eq. 10 is Table 4's form times CF 1.017.

## 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 = 20, rho = 0.8 | 126 | 126 | Computed from the printed form: hand-computed from the published form |

Cite: https://treeallometry.org/equations/komiyama-2005-eq10-root/#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: Komiyama, A., Poungparn, S., Kato, S. (2005). Common allometric equations for estimating the tree weight of mangroves. Journal of Tropical Ecology, 21(4), 471–477. https://doi.org/10.1017/S0266467405002476

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Common mangrove root weight (Eq. 10)", checked 2026-11-01, https://treeallometry.org/equations/komiyama-2005-eq10-root/. 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/komiyama-2005-eq10-root.json
Report a problem: email info@restorationscope.com with the equation id (komiyama-2005-eq10-root) and where the right value appears.