{"id":"cihak-2018-agb-d","source":{"id":"cihak-2018","citation":"Čihák, T., & Vejpustková, M. (2018). Parameterisation of allometric equations for quantifying aboveground biomass of Norway spruce (Picea abies (L.) H. Karst.) in the Czech Republic. Journal of Forest Science, 64(3), 108–117.","title":"Parameterisation of allometric equations for quantifying aboveground biomass of Norway spruce (Picea abies (L.) H. Karst.) in the Czech Republic","authors":["Čihák, T.","Vejpustková, M."],"year":2018,"venue":"Journal of Forest Science","doi":"10.17221/61/2017-jfs","url":"https://doi.org/10.17221/61/2017-jfs","read_url":"https://www.agriculturejournals.cz/publicFiles/61_2017-JFS.pdf","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Norway spruce, Czech Republic: Total aboveground biomass from D (Table 2)","output":{"quantity":"agb"},"expression":"exp(-1.95298 + 2.35768 * ln(D)) * 0.986","published":{"expression":"exp(-1.95298 + 2.35768 * ln(D)) * 0.986","units":{"D":"cm"},"output_unit":"kg"},"taxon":{"level":"species","name":"Picea abies","family":"Pinaceae","group":"conifer"},"region":{"scope":"national","countries":["CZ"],"place":"25 stands on 15 sites, Czech Republic (acidic and nutrient-medium sites)","biomes":["temperate"]},"stand":"mixed","fit":{"n_trees":139,"r2":0.95,"cf":0.986,"method":"log-log linear regression with Marklund (1987) back-transformation correction factor"},"evidence":[{"field":"expression","quote":"AGB = exp(b0 + b1ln(D))λ; b0 = -1.95298, b1 = 2.35768, λ = 0.986","locator":"Table 2 and Eq. 2, p. 113 and p. 110"},{"field":"fit.n_trees","quote":"an extensive data set of 139 spruce trees collected in 25 stands on 15 sites","locator":"Abstract"}],"check":[{"inputs":{"D":10},"expected":31.8705,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":25},"expected":276.4418,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":45},"expected":1105.2348,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Coefficients, R2 and lambda as printed in Table 2 (lambda per Marklund 1987, Eq. 3, already multiplied in). H/D is slenderness ratio, tree height (m) over DBH (cm). Not recommended for trees with D < 7 cm. Table 2 also gives models with site index (SI) or tree age (A) and crown biomass models, not added here (no canonical variable for SI or A; crown has no output quantity)."}