# Teak stem biomass, fertilized stands and unfertilized clonal stands (DBS) Stem biomass equation for Tectona grandis, Brazil, from Santos et al. 2022. 15 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it. ## Equation As printed in Santos et al. 2022 (Table 2, model in caption; DBS row, Fertilized and clonal not fertilized columns β₀ and β₁, p. 5): > LnY = β₀ + β₁ Lndbh + ε; β₀ = −3.5300, β₁ = 2.6025 Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#equation In this library's units, ready to compute (stem biomass in kg): ``` Stem biomass = exp(-3.5300 + 2.6025 * ln(D)) ``` Inputs: D = Diameter at breast height (1.3 m) (cm). The source's own form: exp(-3.5300 + 2.6025 * ln(DBH)), with DBH in cm; output in kg. Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#canonical ## What it covers - Output: Stem biomass, kg - Taxon: Tectona grandis (species); broadleaf - Where: Mato Grosso, Brazil. Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#where - Biomes: not stated - Stand: plantation - Trees measured: 15. Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#n_trees - R²: 0.9971. Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#r2 - Method: log-linear regression. Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#method - Verification: read in the original source - Last checked: 2026-11-05. Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#checked_at A missing fit statistic is one the source doesn't state, or that we haven't recorded; it is never estimated. Outside the stated DBH range or region, the equation is an extrapolation. ## Source Santos, M. L., Leite, H. G., Cavalcante, V. S., Fernandes, L. V., and Neves, J. C. L. (2022). Allometric equations for biomass and contents of macronutrients in a young Tectona grandis stand. Revista Brasileira de Ciência do Solo, 46, e0220030. - DOI: https://doi.org/10.36783/18069657rbcs20220030 - Peer review: A paper in a peer-reviewed journal. - Access: open access - Copy we read: https://www.rbcsjournal.org/wp-content/uploads/articles_xml/1806-9657-rbcs-46-e0220030/1806-9657-rbcs-46-e0220030.pdf - Every equation from this source: https://treeallometry.org/sources/santos-2022/ - Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#source ## The facts, in the source's words **Equation** (Table 2, model in caption; DBS row, Fertilized and clonal not fertilized columns β₀ and β₁, p. 5): > LnY = β₀ + β₁ Lndbh + ε; β₀ = −3.5300, β₁ = 2.6025 Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#equation **Equation** (Table 2, DBS, Fertilized and clonal not fertilized, p. 5): > -3.5300 2.6025 0.9971 Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-expression **Equation** (Materials and methods, p. 4): > ln Y = β0 + β1 ln DBH + ε (m1) Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-expression-2 **Output** (Figure 2 caption, p. 7): > Estimates of the dry biomass of aerial part – DBAP (a), stem – DBS (b), wood – DBW (c) Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-output **Units** (Figure 2 horizontal axis, p. 7): > DBH (cm) Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-published-units **Units** (Figure 2 vertical axis, p. 7): > DBS (kg/tree) Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-published-units-2 **Trees measured** (Materials and methods, data sets, p. 4): > 2) trees from fertilized stands and unfertilized clonal stands (15 trees, 12 clonal and 3 seminal); Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-fit-n-trees **R²** (Table 2, DBS, Fertilized and clonal not fertilized, p. 5): > -3.5300 2.6025 0.9971 Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-fit-r2 **method** (Materials and methods, p. 4): > The allometric model used was ln Y = β0 + β1 ln DBH + ε (m1) Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-fit-method **Taxon** (Title, p. 1): > young Tectona grandis stand Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-taxon **Where** (Study area, p. 2): > Mato Grosso, Brazil Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-region **stand** (Abstract, p. 1): > teak plantations Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#quote-stand **Our note:** DBH is measured at 1.3 m. The log-linear model is back-transformed using Table 2's printed coefficients; the paper gives no correction factor, so none is applied. The authors instead recommend the all-stands fit because it is more robust. ## Checks this equation passes On every build, the library's form and the source's own form (in its units) must both give these values within 1%. | Inputs | Expected | We get | From | | --- | --- | --- | --- | | D = 15 | 33.7 | 33.7 | Computed from the printed form: Calculated from the Table 2 log-linear form at DBH 15 cm. | Cite: https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/#checks The calculator on the page shows carbon as biomass × 0.47 (IPCC 2006 Guidelines, Vol. 4, Ch. 4, Table 4.3) and CO₂e as carbon × 44/12. ## How to cite Cite the source for the equation: Santos, M. L., Leite, H. G., Cavalcante, V. S., Fernandes, L. V., and Neves, J. C. L. (2022). Allometric equations for biomass and contents of macronutrients in a young Tectona grandis stand. Revista Brasileira de Ciência do Solo, 46, e0220030. https://doi.org/10.36783/18069657rbcs20220030 Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Teak stem biomass, fertilized stands and unfertilized clonal stands (DBS)", checked 2026-11-05, https://treeallometry.org/equations/santos-2022-stem-fertilized-and-clonal/. Data CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Quotes are the authors' words. Data for this equation: https://treeallometry.org/data/equations/santos-2022-stem-fertilized-and-clonal.json Report a problem: email info@restorationscope.com with the equation id (santos-2022-stem-fertilized-and-clonal) and where the right value appears.