Tree Allometrics

Equations / Branch biomass

Pinus sylvestris branches biomass vs DBH (Eq. 4), forest-swamp, Middle Urals

Branch biomassPinus sylvestris · PinaceaeRussianaturalRead from the original paper
Photo of Pinus sylvestris
© Douglas Goldman · CC BY-SA · iNaturalist
Equation

As printed (Eq. (4) and Table 4, p. 126)

lnPi = a0 + a1lnD (4); lnPbr: a0 = –4,8556, a1 = 2,5829

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

Branch biomass = exp(-4.8556 + 2.5829 * ln(D))
D
Diameter at breast height (1.3 m), cm

The Baskerville log-correction is already in the printed intercept a0 (Table 4 footnote), so no separate factor. adjusted R2 reported: 0.908 (not used as r2). Pa excludes dead branches (reported separately as Pmort); the contract cannot express that exclusion. Only the 4 main fractions (stem in bark, branches, foliage, total) are added; bark and dead-branch fits omitted. 18 birch and 12 pine trees from 4 plots in one forest-swamp system. Sampled pines are P. sylvestris f. uliginosa and f. litwinowii (Table 1, p. 121).

Source
18 и 12 деревьев соответственно березы и сосны
Trees measured · Abstract (RU)
Trees measured
12
DBH range
2.4–21.3 cm
Height range
3.67–12.8 m
Residual SE
0.53
Method
log-log regression (OLS on natural logs); Baskerville correction included in the intercept
Where
Forest-swamp system by Lake Isetskoe, Sverdlovsk Oblast, Middle Urals
Last checked
2026-11-01
Calculate
0.497
Branch biomass (kg)
0.234
Carbon (kg), ×0.47
0.857
CO₂e (kg), ×44/12
Fitted DBH range020406080100120510152025303540DBH (cm)Branch biomass (kg)Branch biomass

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%.

InputsExpectedWe getFrom
D = 50.4970.497Computed from the printed form
hand-computed from the published form (Table 4 coefficients)
D = 102.982.98Computed from the printed form
hand-computed from the published form (Table 4 coefficients)
D = 158.498.49Computed from the printed form
hand-computed from the published form (Table 4 coefficients)

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