# Tanzania Cultivated land, height from D (base model, Table 4)

Height equation for Mixed tree species, Cultivated land, Tanzania, from Mugasha et al. 2019. 1,866 trees, DBH 1–149.9 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Mugasha et al. 2019 (Table 4, Cultivated land row):

> 1.3 + 13.6509 × (1 − exp(−0.06223 × D0.8600))

Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#equation

In this library's units, ready to compute (height in m):

```
Height = 1.3 + 13.6509 * (1 - exp(-0.06223 * D^0.86))
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 1.3 + 13.6509 * (1 - exp(-0.06223 * DBH^0.86)), with DBH in cm; output in m.
Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#canonical

## What it covers

- Output: Height, m
- Taxon: Mixed tree species, Cultivated land (mixed species); mixed
- Where: Tanzania Mainland, NAFORMA inventory (Cultivated land). Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#where
- Biomes: tropical
- Stand: mixed
- Trees measured: 1,866. Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#n_trees
- DBH range: 1–149.9 cm. Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#dbh
- Height range: 1.5–35 m. Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#height
- Method: nonlinear mixed-effects regression (random effect on cluster), Weibull form. Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#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

Mugasha, W.A., Mauya, E.W., Njana, A.M., et al. (2019). Height-Diameter Allometry for Tree Species in Tanzania Mainland. International Journal of Forestry Research, 2019, 4832849.

- DOI: https://doi.org/10.1155/2019/4832849
- Access: open access
- Copy we read: https://onlinelibrary.wiley.com/doi/10.1155/2019/4832849
- Every equation from this source: https://treeallometry.org/sources/mugasha-2019/
- Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#source

## The facts, in the source's words

**Equation** (Table 4, Cultivated land row):

> 1.3 + 13.6509 × (1 − exp(−0.06223 × D0.8600))

Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#equation

**Trees measured** (Table 1, H, Cultivated column):

> Number of trees 1866

Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#quote-fit-n-trees

**Our note:** Base model (D only) fitted on NAFORMA data. n_trees and ranges are the Table 1 descriptive statistics for this forest type (the data the model was fitted on). Generalized models with basal area/climate are not captured. Exponent printed flattened in the HTML text (D followed by the exponent); read as D^exponent.

## 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 | 4.3 | 4.3 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 20 | 8.93 | 8.93 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 50 | 12.7 | 12.7 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/mugasha-2019-h-cultivated/#checks

## How to cite

Cite the source for the equation: Mugasha, W.A., Mauya, E.W., Njana, A.M., et al. (2019). Height-Diameter Allometry for Tree Species in Tanzania Mainland. International Journal of Forestry Research, 2019, 4832849. https://doi.org/10.1155/2019/4832849

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Tanzania Cultivated land, height from D (base model, Table 4)", checked 2026-11-02, https://treeallometry.org/equations/mugasha-2019-h-cultivated/. 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/mugasha-2019-h-cultivated.json
Report a problem: email info@restorationscope.com with the equation id (mugasha-2019-h-cultivated) and where the right value appears.