# Miombo Regional total volume from stump diameter

Total volume equation for Miombo woodland trees (mixed species), Tanzania, from Manyanda et al. 2019. 114 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Manyanda et al. 2019 (Table 4, selected model (1)):

> Regional = a × (SD) b 0.000032 2.7992 -90.16 1.01 71.7 -10.5 0.709

Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#equation

In this library's units, ready to compute (total volume in m³):

```
Total volume = 3.2e-05 * D30^2.7992
```

Inputs: D30 = Stem diameter at 30 cm (cm).
The source's own form: 3.2e-05 * SD^2.7992, with SD in cm; output in m3.
Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#canonical

## What it covers

- Output: Total volume, m³
- Taxon: Miombo woodland trees (mixed species) (mixed species); broadleaf
- Where: Miombo woodlands of Manyara, Lindi and Tabora, Tanzania. Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 114. Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#n_trees
- R²: 0.709. Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#r2
- Method: non-linear mixed-effects regression (nlme), power model. Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#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

Manyanda, B.J., Mugasha, W.A., Nzunda, E.F., Malimbwi, R.E. (2019). Biomass and Volume Models Based on Stump Diameter for Assessing Degradation of Miombo Woodlands in Tanzania. International Journal of Forestry Research, 2019, 1876329.

- DOI: https://doi.org/10.1155/2019/1876329
- Access: open access
- Copy we read: https://onlinelibrary.wiley.com/doi/10.1155/2019/1876329
- Every equation from this source: https://treeallometry.org/sources/manyanda-2019/
- Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#source

## The facts, in the source's words

**Equation** (Table 4, selected model (1)):

> Regional = a × (SD) b 0.000032 2.7992 -90.16 1.01 71.7 -10.5 0.709

Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#equation

**Units** (Section 2.3.4):

> SD is stump diameter (cm)

Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#quote-published-units

**Trees measured** (Abstract (volume: 114 trees)):

> AGB and BGB models were developed from 127 and 57 sample trees, respectively

Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#quote-fit-n-trees

**Our note:** Stump diameter (SD) is measured over bark just below the felling cut, at least 30 cm above ground (higher when the stump is irregular), so it is mapped to D30 as the nearest canonical variable. Form Y = a × SD^b is the first (non-linear mixed-effects, nlme) model form; the paper selected it as best in every case shown here, and the printed Table row shows it. Volume is of merchantable stem plus branches (to 2.5 cm top), above the SD point. The three model forms (1)-(3) are typeset equations; the form of (1) is read from the table row "= a × (SD) b". The fit used nlme with random effects; coefficients are the fixed effects as printed. Table 2 gives SD ranges, not DBH, so no dbh range is stored.

## 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 |
| --- | --- | --- | --- |
| D30 = 30 | 0.436 | 0.436 | Computed from the printed form: hand-computed from the published form |
| D30 = 60 | 3.04 | 3.04 | Computed from the printed form: hand-computed from the published form |

Cite: https://treeallometry.org/equations/manyanda-2019-volume-regional/#checks

## How to cite

Cite the source for the equation: Manyanda, B.J., Mugasha, W.A., Nzunda, E.F., Malimbwi, R.E. (2019). Biomass and Volume Models Based on Stump Diameter for Assessing Degradation of Miombo Woodlands in Tanzania. International Journal of Forestry Research, 2019, 1876329. https://doi.org/10.1155/2019/1876329

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Miombo Regional total volume from stump diameter", checked 2026-11-02, https://treeallometry.org/equations/manyanda-2019-volume-regional/. 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/manyanda-2019-volume-regional.json
Report a problem: email info@restorationscope.com with the equation id (manyanda-2019-volume-regional) and where the right value appears.