# Chir pine height from D (M1, power)

Height equation for Pinus roxburghii, Nepal, from Thapa et al. 2013. 180 trees, DBH 5.57–61.94 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Thapa et al. 2013 (Results and Discussion, p. 150):

> M1 i.e. H = e(-0.276) D0.925 is considered best fitted model

Cite: https://treeallometry.org/equations/thapa-2013-h-power/#equation

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

```
Height = exp(-0.276) * D^0.925
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: exp(-0.276) * DBH^0.925, with DBH in cm; output in m.
Cite: https://treeallometry.org/equations/thapa-2013-h-power/#canonical

## What it covers

- Output: Height, m
- Taxon: Pinus roxburghii (species), family Pinaceae; conifer
- Where: Galeshwor Thulo Salleri and Banchare Dil community forests, Ghatan VDC, Myagdi district, west Nepal. Cite: https://treeallometry.org/equations/thapa-2013-h-power/#where
- Biomes: subtropical, montane
- Stand: natural
- Trees measured: 180. Cite: https://treeallometry.org/equations/thapa-2013-h-power/#n_trees
- DBH range: 5.57–61.94 cm. Cite: https://treeallometry.org/equations/thapa-2013-h-power/#dbh
- Height range: 2.5–35 m. Cite: https://treeallometry.org/equations/thapa-2013-h-power/#height
- R²: 0.91. Cite: https://treeallometry.org/equations/thapa-2013-h-power/#r2
- Method: nonlinear least squares, H = exp(b0) D^b1 (R2 adj. reported). Cite: https://treeallometry.org/equations/thapa-2013-h-power/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/thapa-2013-h-power/#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

Thapa, T. B., Upadhyaya, C. P., Timilsina, Y. P., Bhandari, S. K., & Puri, L. (2013). Predicting total height from diameter using nonlinear models in Pinus roxburghii. Nepal Journal of Science and Technology, 14(1), 147–152.

- DOI: https://doi.org/10.3126/njst.v14i1.8935
- Access: open access
- Copy we read: https://www.nepjol.info/index.php/NJST/article/download/8935/7338
- Every equation from this source: https://treeallometry.org/sources/thapa-2013/
- Cite: https://treeallometry.org/equations/thapa-2013-h-power/#source

## The facts, in the source's words

**Equation** (Results and Discussion, p. 150):

> M1 i.e. H = e(-0.276) D0.925 is considered best fitted model

Cite: https://treeallometry.org/equations/thapa-2013-h-power/#equation

**Trees measured** (Abstract):

> Total height and diameter at breast height of 180 trees were measured

Cite: https://treeallometry.org/equations/thapa-2013-h-power/#quote-fit-n-trees

**R²** (Abstract; Table 3, M1):

> R2 adj.=0.910

Cite: https://treeallometry.org/equations/thapa-2013-h-power/#quote-fit-r2

**Smallest DBH** (Table 1, Diameter (cm) rows (smallest minimum and largest maximum across the six diameter classes)):

> Minimum 5.57 ... Maximum 61.94

Cite: https://treeallometry.org/equations/thapa-2013-h-power/#quote-fit-dbh-min-cm

**Our note:** r2 is the adjusted R2 as printed. RMSE 1.221 (Table 3). Models M2-M5 are printed in Table 3 with parameters rounded (several show -0.000), so only the selected M1 is recorded. 30 trees per diameter class, 6 classes.

## 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 | 6.38 | 6.38 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 25 | 14.9 | 14.9 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 50 | 28.3 | 28.3 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/thapa-2013-h-power/#checks

## How to cite

Cite the source for the equation: Thapa, T. B., Upadhyaya, C. P., Timilsina, Y. P., Bhandari, S. K., & Puri, L. (2013). Predicting total height from diameter using nonlinear models in Pinus roxburghii. Nepal Journal of Science and Technology, 14(1), 147–152. https://doi.org/10.3126/njst.v14i1.8935

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Chir pine height from D (M1, power)", checked 2026-11-02, https://treeallometry.org/equations/thapa-2013-h-power/. 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/thapa-2013-h-power.json
Report a problem: email info@restorationscope.com with the equation id (thapa-2013-h-power) and where the right value appears.