Equations / Branch biomass
Birch living branch biomass, young dense stands, N Sweden (Table 5)
As printed (Table 5, p. 12)
In this library's units, ready to compute (kg)
Branch biomass = exp(-4.190 + (0.011 + 0.105) / 2 + 11.826 * D / (D + 6) + (-3.939) * H / (H + 10))D- Diameter at breast height (1.3 m), cm
H- Total tree height, m
Fitted on pine-dominated mixed stands; fit n, DBH and height ranges are the species sample ranges. Expression applies the paper's stated additive correction (var(uk) + var(eki))/2 to the intercept. Variance values are as printed in Table 5; no other correction factor is stated. Living branches only (dead branches are modelled separately and not included). Birch coefficients are for Betula pendula and B. pubescens pooled.
doi:10.14214/sf.1190 · Open access · copy we read
a variance correction term, ((var(uk) + var(eki))/2) should be added to the intercept to correct for bias due to the logarithmic transformation
In total, 280 trees were included in this destructive aboveground biomass study, of which 126 were pine, 68 spruce and 86 birch.
The range of dbh was 1–22 cm, 1–21 cm and 1–11 cm for pine, spruce and birch, respectively
The range of heights was 1.7–11.7 m, 1.6–13.3 m and 1.8–8.6 m for pine, spruce and birch, respectively
- Trees measured
- 86
- DBH range
- 1–11 cm
- Height range
- 1.8–8.6 m
- Method
- linear mixed model of ln(biomass) with random stand effect; ln(y) = Intercept + b1 dbh/(dbh + n) + b2 h/(h + m)
- Where
- Six young, dense, naturally regenerated stands in northern Sweden (63.26-65.69 N)
- Last checked
- 2026-11-02
Shaded: the DBH range the model was fitted on. Other inputs held at the values above.
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 = 5, H = 5 | 0.933 | 0.933 | Computed from the printed form hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction |
| D = 10, H = 8 | 4.52 | 4.52 | Computed from the printed form hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction |
Related
- White birch branch biomass from D only (MS-2) (Table 5) · Dong et al. 2018 · DBH
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- Betula papyrifera branch biomass, cross-sectional area at 0.3 m (NLS) · Flade et al. 2021 · D30
- Betula pendula branches biomass vs DBH (Eq. 4), forest-swamp, Middle Urals · Petrova et al. 2026 · DBH
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