{"id":"pan-2022-bgb-total-disagg-heilongjiang","source":{"id":"pan-2022","citation":"Pan, L., & Wang, X. (2022). Additive Root Biomass Equations for Betula platyphylla Suk. Plantations in Northeast China. Forests, 13(5), 661.","title":"Additive Root Biomass Equations for Betula platyphylla Suk. Plantations in Northeast China","authors":["Pan, L.","Wang, X."],"year":2022,"venue":"Forests","doi":"10.3390/f13050661","url":"https://doi.org/10.3390/f13050661","read_url":"https://www.mdpi.com/1999-4907/13/5/661/pdf?version=1650953273","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current"},"name":"Birch total root biomass, disaggregated model (Eq. 24), Heilongjiang site","output":{"quantity":"bgb"},"expression":"exp(-1.0113 + 2.2706 * ln(D) - 0.8676 * ln(H))","published":{"expression":"exp(-1.0113 + 2.2706 * ln(DBH) - 0.8676 * ln(HT) - 0.0108 * 0 - 0.6541 * 0)","units":{"DBH":"cm","HT":"m"},"variables":{"DBH":"D","HT":"H"},"output_unit":"kg"},"taxon":{"level":"species","name":"Betula platyphylla","family":"Betulaceae","group":"broadleaf"},"region":{"scope":"site","countries":["CN"],"place":"Maoer mountains, Heilongjiang Province, Northeast China","biomes":["temperate"]},"stand":"plantation","fit":{"n_trees":493,"dbh_min_cm":3.4,"dbh_max_cm":11.9,"h_min_m":4.5,"h_max_m":14,"method":"log-transformed (multiplicative error) nonlinear system with site dummies"},"evidence":[{"field":"fit.n_trees","quote":"with a total of 493 sample trees","locator":"Section 2.1"},{"field":"fit.dbh_min_cm","quote":"Min 3.40 4.50 0.10 0.02 0.02 0.14","locator":"Table 2 (DBH 3.4 cm, HT 4.5 m minimum)"},{"field":"fit.dbh_max_cm","quote":"Max 11.90 14.00 9.29 10.19 3.98 20.27","locator":"Table 2 (DBH 11.9 cm, HT 14.0 m maximum)"},{"field":"expression","quote":"ft(D, H; βt) = exp[Bt1 + βt2 ln DBH + βt3 ln HT + βts2S2 + βts3S3]","locator":"Eq. 24, Section 3.3"},{"field":"expression","quote":"ft βt1 −1.0113 0.1807 0.0000; βt2 2.2706 0.1251 0.0000; βt3 −0.8676 0.12 0.0000; βts2 −0.0108 0.0946 0.9088; βts3 −0.6541 0.0682 0.0000","locator":"Table 6"}],"check":[{"inputs":{"D":8,"H":9.4},"expected":5.8488,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":11,"H":13},"expected":9.0976,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Total root biomass function ft of the disaggregated system. Site: Heilongjiang (Maoer mountains), baseline site with S2 = 0 and S3 = 0. The paper fits one model with site dummies (Liaoning when S2 = 1 and S3 = 0, Jilin when S2 = 0 and S3 = 1, Heilongjiang when S2 = 0 and S3 = 0); this file sets the dummies for one site. It is fitted on all 493 trees from the three sites (Heilongjiang 333, Jilin 26, Liaoning 134 per Table 1), so the site term is a shift on common slopes. The paper reports no back-transform correction factor for the log-normal error and none is applied. The paper reports only ten-fold cross-validation R2, not a fit R2, so none is given here. Roots were excavated and sieved into coarse (>5 mm), medium (2-5 mm) and fine (<2 mm) classes; the total includes all three."}