# B. alnoides stem volume from DBH, 31–50 cm (Table 5)

Stem volume equation for Betula alnoides, India, from Giri et al. 2019. 25 trees, DBH 31–50 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Giri et al. 2019 (Table 5, Diameter class 31–50 cm):

> V = 6.272*d2

Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#equation

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

```
Stem volume = 6.272 * (D/100)^2
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 6.272 * d^2, with d in m; output in m3.
Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#canonical

## What it covers

- Output: Stem volume, m³
- Taxon: Betula alnoides (species), family Betulaceae; broadleaf
- Where: Meghalaya, NE India (Garo, Khasi, Jaintia Hills and Ri-Bhoi districts). Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#where
- Biomes: tropical, subtropical
- Stand: natural
- Trees measured: 25. Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#n_trees
- DBH range: 31–50 cm. Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#dbh
- Method: Linear regression through the origin (SPSS), non-destructive frustum volumes (Newton's formula). Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#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

Giri, K., Pandey, R., Jayaraj, R.S.C., Nainamalai, R., Ashutosh, S. (2019). Regression equations for estimating tree volume and biomass of important timber species in Meghalaya, India. Current Science, 116(1), 75-81.

- DOI: https://doi.org/10.18520/cs/v116/i1/75-81
- Access: open access
- Every equation from this source: https://treeallometry.org/sources/giri-2019/
- Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#source

## The facts, in the source's words

**Equation** (Table 5, Diameter class 31–50 cm):

> V = 6.272*d2

Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#equation

**Units** (Statistical analysis (Methods)):

> all the parameters were converted into metres, and volume was calculated in cubic metres

Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#quote-published-units

**Trees measured** (Table 1 footnote):

> n = 75, 25 trees for each diameter class

Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#quote-fit-n-trees

**Smallest DBH** (Statistical analysis (Methods)):

> All the trees were divided into three diameter classes according to their DBH, viz. 10–30, 31–50 and >50 cm

Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#quote-fit-dbh-min-cm

**Our note:** Class-specific model: use only for trees in the stated DBH class. Non-destructive: volumes of standing trees were summed from laser-rangefinder frustum measurements (stem volume), not felled. The paper states d and h in metres, so published units use m; canonical form divides D (cm) by 100. Adj. R² and SE are printed per class but not stored (adj. R² is not R²). The class bounds are the sampling classes; the paper gives no measured DBH range. The paper also gives biomass = stem volume x wood specific gravity (not a fitted model, not added).

## 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 = 40 | 1 | 1 | Computed from the printed form: computed from the Table 5 coefficient |

Cite: https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/#checks

## How to cite

Cite the source for the equation: Giri, K., Pandey, R., Jayaraj, R.S.C., Nainamalai, R., Ashutosh, S. (2019). Regression equations for estimating tree volume and biomass of important timber species in Meghalaya, India. Current Science, 116(1), 75-81. https://doi.org/10.18520/cs/v116/i1/75-81

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "B. alnoides stem volume from DBH, 31–50 cm (Table 5)", checked 2026-11-02, https://treeallometry.org/equations/giri-2019-betula-alnoides-31-50-d2/. 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/giri-2019-betula-alnoides-31-50-d2.json
Report a problem: email info@restorationscope.com with the equation id (giri-2019-betula-alnoides-31-50-d2) and where the right value appears.