{"id":"pan-2022-bgb-total-additive-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, additive system (coarse + medium + fine), Heilongjiang site","output":{"quantity":"bgb"},"expression":"exp(-0.9679 + 2.2547 * ln(D) - 1.1789 * ln(H)) + exp(-2.7028 + 2.2534 * ln(D) - 0.6586 * ln(H)) + exp(-3.7903 + 2.313 * ln(D) - 0.361 * ln(H))","published":{"expression":"exp(-0.9679 + 2.2547 * ln(DBH) - 1.1789 * ln(HT) + 0.2733 * 0 - 0.8561 * 0) + exp(-2.7028 + 2.2534 * ln(DBH) - 0.6586 * ln(HT) - 0.3815 * 0 - 0.7157 * 0) + exp(-3.7903 + 2.313 * ln(DBH) - 0.361 * ln(HT) - 0.3346 * 0 - 0.2382 * 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":"Y4 = Yt = M ∑ m=1 Ym = f1(X1, B1) + f2(X2, β2) + f3(X3, β3) + ε4","locator":"Eq. 7, Section 2.4"},{"field":"expression","quote":"fc(D, H; βt) = exp(βc1 + βc2 ln DBH + βc3 ln HT + βcs2S2 + βcs3S3 + εc)","locator":"Eq. 21, Section 3.2"},{"field":"expression","quote":"Coarse βc1 −0.9679 0.2008 0.0000; βc2 2.2547 0.1435 0.0000; βc3 −1.1789 0.1369 0.0000; βcs2 0.2733 0.0932 0.0034; βcs3 −0.8561 0.0943 0.0000","locator":"Table 5"},{"field":"expression","quote":"Medium βm1 −2.7028 0.1985 0.0000; βm2 2.2534 0.1356 0.0000; βm3 −0.6586 0.1282 0.0000; βms2 −0.3815 0.1287 0.0031; βms3 −0.7157 0.0746 0.0000","locator":"Table 5"},{"field":"expression","quote":"Fine βc1 −3.7903 0.2251 0.0000; βc2 2.313 0.1463 0.0000; βc3 −0.361 0.1446 0.0126; βcs2 −0.3346 0.1323 0.0116; βcs3 −0.2382 0.0572 0.0000","locator":"Table 5 (fine-root rows are printed with the symbols of the coarse root, βc...; read as the fine-root parameters)"}],"check":[{"inputs":{"D":8,"H":9.4},"expected":5.837,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":11,"H":13},"expected":9.1585,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Sum of the three additive root-class equations (Eq. 7, 21-23). Site: Heilongjiang (Maoer mountains), baseline site with S2 = 0 and S3 = 0. Table 5 prints the fine-root rows with the symbols of the coarse root; the order of the rows (Coarse, Medium, Fine) is used to assign them. 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."}