Equations / Aboveground biomass

Vietnam evergreen forest AGB with DBH, height and wood density (Eq. 10)

Aboveground biomassMixed species of tropical evergreen forest (45 species)VietnamnaturalRead from the original paper

Many species, no single photo

Equation

As printed (Eq. 10)

ln(AGB) = −3.081 + 0.966 ln(DBH²H) + 0.305 ln(WD)

In this library's units, ready to compute (kg)

Aboveground biomass = 1.030 * exp(-3.081 + 0.966 * ln(D^2 * H) + 0.305 * 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

Eq. 10 times the CF 1.030 from Table 2. The paper's Eq. 11 back-transformed form prints 'exp(3,051 + ... + 3.05 ln(WD))', a typo; Table 5 prints exp(-3.051 + 0.966 ln(DBH2H) + 0.305 ln(WD)), i.e. the CF folded into the intercept (ln 1.030 = 0.030). H is the felled stem length. Functional-group models (Eq. 12-15) have no printed CF and are not included.

Source

Nam, V.T., van Kuijk, M., Anten, N.P.R. (2016). Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam. PLoS ONE, 11(6), e0156827.

doi:10.1371/journal.pone.0156827 · Open access

8 ln(AGB) = a + hln(DBH2H) + cln(WD) 0.986 0.245 -841.2 19.8 1.030

Fit · Table 2, model 8

a total of 300 trees pertaining to 45 species

Trees measured · Methods

AGB = exp(-3.051+0.966ln(DBH2H) +0.305ln(WD)) ... 300 ... 1.8–115.0 ... Vietnam

DBH range · Table 5

Trees measured: 300
DBH range: 1.8–115 cm
R²: 0.986
Residual SE: 0.245
Correction factor: 1.03 (applied)
Method: OLS on ln-transformed data, adjusted R2 (Table 2 model 8)
Where: K'Bang district, Gia Lai province, Central Highlands, Vietnam
Last checked: 2026-11-01

Calculate

DBH (cm)Height (m)Wood density (g/cm³)

Height from

530

Aboveground biomass (kg)

249

Carbon (kg), ×0.47

913

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 = 30, H = 20, rho = 0.63	530	530	Computed from the printed form hand-computed from the published form
D = 60, H = 30, rho = 0.63	2,991	2,991	Computed from the printed form hand-computed from the published form

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