{"id":"karaban-2023-stem-d","source":{"id":"karaban-2023","citation":"Karaban, A. A., Usoltsev, V. A., Tretyakov, S. V., Koptev, S. V., Paramonov, A. A., Tsvetkov, I. V., Davydov, A. V., & Tsepordey, I. S. (2023). Biomass of gray alder trees and its allometric models in the conditions of the Arkhangelsk region. Forests of Russia and economy in them, 2(85), 42–50.","title":"Biomass of gray alder trees and its allometric models in the conditions of the Arkhangelsk region","authors":["Karaban, A. A.","Usoltsev, V. A.","Tretyakov, S. V."],"year":2023,"venue":"Forests of Russia and economy in them (Леса России и хозяйство в них)","doi":"10.51318/fret.2023.36.20.005","url":"https://doi.org/10.51318/fret.2023.36.20.005","read_url":"https://usfeu.ru/media/filer_public/31/1c/311c8894-375c-49bb-9c23-860c9d9a5c51/5_karaban_usoltsev_dr_biomassa_derevev_olkhi.pdf","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Gray alder, Arkhangelsk: stem biomass (in bark) from D (Table 2)","output":{"quantity":"stem_biomass"},"expression":"exp(-2.8211 + 2.5081 * ln(D))","published":{"expression":"exp(-2.8211 + 2.5081 * ln(D))","units":{"D":"cm"},"output_unit":"kg"},"taxon":{"level":"species","name":"Alnus incana","family":"Betulaceae","group":"broadleaf"},"region":{"scope":"regional","countries":["RU"],"place":"Arkhangelsk region, northern taiga (Primorsky, Krasnoborsky and Kargopolsky districts)","biomes":["boreal"]},"stand":"mixed","fit":{"n_trees":50,"dbh_min_cm":3.6,"dbh_max_cm":16.9,"rse":0.357,"method":"OLS regression on natural logarithms; free term corrected for log transformation (Baskerville 1972)"},"evidence":[{"field":"expression","quote":"ln Ps (1) –2,8211 2,5081 – – 0,835 0,357 (ln Pi = a0 + a1 ln D)","locator":"Table 2, ln Ps row"},{"field":"fit.n_trees","quote":"Полная характеристика полученных данных о 50 модельных деревьях ольхи серой дана в табл. 1.","locator":"Methods, p. 44"},{"field":"fit.dbh_min_cm","quote":"25 20 3,6 5,10 12,22 6,48 0,004 0,001 2,596 0,121 0,230 0,049 2,875 4,250","locator":"Table 1, tree No. 25 (smallest D, 3.6 cm); largest D is tree No. 15, 16.9 cm"}],"check":[{"inputs":{"D":5},"expected":3.3721,"origin":"computed","note":"computed from the published form (coefficients as printed; free term already includes the Baskerville log correction per the Table 2 note)"},{"inputs":{"D":10},"expected":19.1828,"origin":"computed","note":"computed from the published form (coefficients as printed; free term already includes the Baskerville log correction per the Table 2 note)"},{"inputs":{"D":15},"expected":53.0355,"origin":"computed","note":"computed from the published form (coefficients as printed; free term already includes the Baskerville log correction per the Table 2 note)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"The note to Table 2 says the free term includes the correction for logarithmic transformation (Baskerville 1972), so no separate factor is applied. Natural log (ln) as printed. The paper reports adjusted R2 (not R2); adjR2 = 0.835. Stand origin not stated (pure stands or with admixture of other species). DBH range is the min and max of column D in Table 1 over the 50 trees. Ps is stem biomass in bark."}