Equations / Aboveground biomass
Subtropical China AGB from D²H and wood density (Model I.2)
Aboveground biomass41 subtropical forest tree species (Fagus lucida, Castanea seguinii, Carpinus viminea and others)ChinanaturalRead from the original paper
Many species, no single photo
Equation
As printed (Table 2, model I.2)
I.2 ln(AGB) = a + bln(D²H) + cln(WD) −2.672 0.944 0.615
In this library's units, ready to compute (kg)
Aboveground biomass = exp(-2.672 + 0.944 * ln(D^2 * H) + 0.615 * ln(rho))D- Diameter at breast height (1.3 m), cm
H- Total tree height, m
rho- Wood density (oven-dry mass / green volume), g/cm³
Log-log model fitted by Bayesian MCMC; no correction factor is stated, so none is applied. Natural log assumed from the paper's ln notation. Wood density WD is in g cm-3 (Table 2; the running text says g/m3). Whole-tree AGB includes branches, leaves and fruit.
Source
doi:10.1890/es15-00198.1 · Open access · copy we read
I.2 R² 0.939 RSE 0.193
we harvested and weighted dry mass of 147 trees from 41 dominant species in subtropical forest
- Trees measured
- 147
- R²
- 0.939
- Residual SE
- 0.193
- Method
- Bayesian log-log regression (MCMC)
- Where
- Badagongshan National Nature Reserve, Hunan province
- Last checked
- 2026-11-02
Calculate
Height from
168.9
Aboveground biomass (kg)
79.4
Carbon (kg), ×0.47
291.1
CO₂e (kg), ×44/12
Shaded: the DBH range the model was fitted on. Other inputs held at the values above.
Checks this equation passes
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 |
|---|---|---|---|
| D = 20, H = 14, rho = 0.57 | 168.9 | 168.9 | Computed from the printed form computed from the printed coefficients |
| D = 40, H = 20, rho = 0.6 | 903.6 | 903.6 | Computed from the printed form computed from the printed coefficients |
Related
- Subtropical China AGB from D, H and wood density (Model I.1) · Xu et al. 2015 · DBH + Height + Wood density
- Subtropical China AGB from D²H x wood density (Model I.3) · Xu et al. 2015 · DBH + Height + Wood density
- Subtropical China AGB from D and wood density (Model I.4) · Xu et al. 2015 · DBH + Wood density
- Subtropical China AGB from D²H (Model III.1) · Xu et al. 2015 · DBH + Height
- Subtropical China root biomass from D · same paper · Root biomass
- Subtropical China AGB from D, H and wood density (Model I.1) · same paper · Aboveground biomass
- Subtropical China AGB from D²H x wood density (Model I.3) · same paper · Aboveground biomass
- Subtropical China AGB from D and wood density (Model I.4) · same paper · Aboveground biomass
- Subtropical China AGB from D²H (Model III.1) · same paper · Aboveground biomass