# Teak height from D (H2, logarithmic)

Height equation for Tectona grandis, Nepal, from Koirala et al. 2017. 31 trees, DBH 6.37–58.92 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Koirala et al. 2017 (Abstract; Table 5, model H2):

> H = [− 5.2544 + (6.8603 × ln (dbh))]

Cite: https://treeallometry.org/equations/koirala-2017-h-log/#equation

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

```
Height = -5.2544 + 6.8603 * ln(D)
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: -5.2544 + 6.8603 * ln(dbh), with dbh in cm; output in m.
Cite: https://treeallometry.org/equations/koirala-2017-h-log/#canonical

## What it covers

- Output: Height, m
- Taxon: Tectona grandis (species), family Lamiaceae; broadleaf
- Where: Sagarnath Forestry Development Project, Sarlahi district, central lowland Nepal. Cite: https://treeallometry.org/equations/koirala-2017-h-log/#where
- Biomes: tropical
- Stand: plantation
- Trees measured: 31. Cite: https://treeallometry.org/equations/koirala-2017-h-log/#n_trees
- DBH range: 6.37–58.92 cm. Cite: https://treeallometry.org/equations/koirala-2017-h-log/#dbh
- Height range: 5.7–26.1 m. Cite: https://treeallometry.org/equations/koirala-2017-h-log/#height
- R²: 0.928. Cite: https://treeallometry.org/equations/koirala-2017-h-log/#r2
- Method: least squares on training set (31 of 44 felled trees). Cite: https://treeallometry.org/equations/koirala-2017-h-log/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/koirala-2017-h-log/#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

Koirala, A., Kizha, A. R., & Baral, S. (2017). Modeling height-diameter relationship and volume of teak (Tectona grandis L.f.) in central lowlands of Nepal. Journal of Tropical Forestry and Environment, 7(1), 28–42.

- DOI: https://doi.org/10.31357/jtfe.v7i1.3020
- Access: open access
- Copy we read: https://web.archive.org/web/2024/http://journals.sjp.ac.lk/index.php/JTFE/article/download/3020/2093
- Every equation from this source: https://treeallometry.org/sources/koirala-2017/
- Cite: https://treeallometry.org/equations/koirala-2017-h-log/#source

## The facts, in the source's words

**Equation** (Abstract; Table 5, model H2):

> H = [− 5.2544 + (6.8603 × ln (dbh))]

Cite: https://treeallometry.org/equations/koirala-2017-h-log/#equation

**Trees measured** (Section 2.2):

> 31 (70 % of the data) were randomly selected to build the model

Cite: https://treeallometry.org/equations/koirala-2017-h-log/#quote-fit-n-trees

**Smallest DBH** (Table 3, training data set):

> dbh (cm) 6.37 58.92; H (m) 5.70 26.10

Cite: https://treeallometry.org/equations/koirala-2017-h-log/#quote-fit-dbh-min-cm

**Our note:** H is total height excluding the 0.10 m stump. R2 0.928 (adj. 0.921), RMSE 1.46 printed in Table 5. Selected as best height-diameter model by the authors.

## 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 | 10.5 | 10.5 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 30 | 18.1 | 18.1 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 55 | 22.2 | 22.2 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/koirala-2017-h-log/#checks

## How to cite

Cite the source for the equation: Koirala, A., Kizha, A. R., & Baral, S. (2017). Modeling height-diameter relationship and volume of teak (Tectona grandis L.f.) in central lowlands of Nepal. Journal of Tropical Forestry and Environment, 7(1), 28–42. https://doi.org/10.31357/jtfe.v7i1.3020

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Teak height from D (H2, logarithmic)", checked 2026-11-02, https://treeallometry.org/equations/koirala-2017-h-log/. 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/koirala-2017-h-log.json
Report a problem: email info@restorationscope.com with the equation id (koirala-2017-h-log) and where the right value appears.