{"id":"dong-2020-ams2-agb-d-h","source":{"id":"dong-2020","citation":"Dong, L., Zhang, Y., Zhang, Z., Xie, L., & Li, F. (2020). Comparison of Tree Biomass Modeling Approaches for Larch (Larix olgensis Henry) Trees in Northeast China. Forests, 11(2), 202.","title":"Comparison of Tree Biomass Modeling Approaches for Larch (Larix olgensis Henry) Trees in Northeast China","authors":["Dong, L.","Zhang, Y.","Zhang, Z."],"year":2020,"venue":"Forests","doi":"10.3390/f11020202","url":"https://doi.org/10.3390/f11020202","read_url":"https://www.mdpi.com/1999-4907/11/2/202/pdf?version=1582977507","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current"},"name":"Larch aboveground biomass from DBH and height, AMS2 (stem + branch + foliage)","output":{"quantity":"agb"},"expression":"(exp(-4.4649) * D^1.698 * H^1.4611) + (exp(-2.0674) * D^2.7545 * H^-1.2799) + (exp(-2.1882) * D^1.9121 * H^-0.733)","published":{"expression":"(exp(-4.4649) * DBH^1.698 * H^1.4611) + (exp(-2.0674) * DBH^2.7545 * H^-1.2799) + (exp(-2.1882) * DBH^1.9121 * H^-0.733)","units":{"DBH":"cm","H":"m"},"variables":{"DBH":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Larix olgensis","family":"Pinaceae","group":"conifer"},"region":{"scope":"regional","countries":["CN"],"place":"Heilongjiang Province, Northeast China (40 plots, 10 sites)","biomes":["temperate"]},"stand":"plantation","fit":{"n_trees":229,"dbh_min_cm":2,"dbh_max_cm":35.7,"h_min_m":3.8,"h_max_m":27,"r2":0.9764,"method":"weighted NSUR (AMS2); aboveground = stem + branch + foliage"},"evidence":[{"field":"fit.n_trees","quote":"the dataset consisted of measurements on 229 larch trees using destructive biomass sampling","locator":"Section 2.1"},{"field":"fit.dbh_min_cm","quote":"DBH (cm) 229 2.0 35.7 17.9 6.9","locator":"Table 1"},{"field":"fit.h_min_m","quote":"H (m) 229 3.8 27.0 16.8 5.4","locator":"Table 1"},{"field":"expression","quote":"the aboveground biomass was also estimated by summing the estimated stem, branch, and foliage biomass","locator":"Section 3.2"},{"field":"expression","quote":"Stem −4.4649 0.0628 1.6980 0.0461 1.4611 0.0579","locator":"Table 3, AMS2, DBH and H"},{"field":"expression","quote":"Branch −2.0674 0.2072 2.7545 0.1547 −1.2799 0.1954","locator":"Table 3, AMS2, DBH and H"},{"field":"expression","quote":"Foliage −2.1882 0.1858 1.9121 0.1323 −0.7330 0.1613","locator":"Table 3, AMS2, DBH and H"},{"field":"fit.r2","quote":"R2 0.9738 0.7172 0.7202 0.9764 (AMS2 row, Stem Branch Foliage Aboveground)","locator":"Table 5, AMS2"}],"check":[{"inputs":{"D":10,"H":9},"expected":20.376,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":25,"H":20},"expected":241.81,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Aboveground biomass is the sum of the three AMS2 component equations as the paper describes (Section 3.2). Additive AMS2 system (aggregated, no constraint) fitted by weighted nonlinear seemingly unrelated regression, the system the authors recommend over the base model when no subsample is available for random effects. Biomass models are exp(b0) * DBH^b1 [* H^b2] with no back-transform factor (nonlinear fit). The paper also gives base model, mixed-effects, AMS1, DMS1 and DMS2 parameters (Tables 2-4), not added here."}