Equations / Aboveground biomass
NZ shrubland shrubs and small trees, dry weight from basal area x height
Fitted on these 4 species and others the paper does not name here: Kunzea ericoides, Leptospermum scoparium, Ulex europaeus, Cytisus scoparius
As printed (Eq. 1 and Figure 3 caption)
In this library's units, ready to compute (kg)
Aboveground biomass = exp(1.0215 * ln(0.785398163397448 * (DRC / 100)^2 * H) + 6.1512)DRC- Root collar / stem base diameter, cm
H- Total tree height, m
Paper predictor is total shrub basal area BA (m2, summed over all stems of the shrub) times maximum shrub height (m). BA is written here as pi/4 * (DRC/100)^2 so DRC is the basal diameter of a single stem, or the equivalent diameter sqrt(sum of d^2) for a multi-stemmed shrub. No back-transform correction is stated. Dry weight is of the whole harvested shrub (foliage and stem were weighed separately and, as the text reads, combined).
doi:10.3390/f5020309 · Open access · copy we read
Overall, 162 shrubs were harvested.
The basal area × height allometric equation accurately (R-square = 0.93) predicted shrub dry weight
- Trees measured
- 162
- R²
- 0.93
- Method
- iterative function minimisation of residual sum of squares, DW = exp(a ln(BA x Height) + b)
- Where
- Oxford (Canterbury) and d'Urville Island, South Island, New Zealand
- Last checked
- 2026-11-02
On every build, the library's form and the paper's own form (in its units) must both give these values within 1%.
| Inputs | Expected | We get | From |
|---|---|---|---|
| DRC = 3, H = 2 | 0.576 | 0.576 | Computed from the printed form computed from the published form (coefficients as printed) |
| DRC = 8, H = 4 | 8.68 | 8.68 | Computed from the printed form computed from the published form (coefficients as printed) |