{"id":"koirala-2017-v-dbh-h","source":{"id":"koirala-2017","citation":"Koirala, A., Kizha, A. R., & Baral, S. (2017). Modeling height-diameter relationship and volume of teak (Tectona grandis L.f.) in central lowlands of Nepal. Journal of Tropical Forestry and Environment, 7(1), 28–42.","title":"Modeling Height-Diameter Relationship and Volume of Teak (Tectona grandis L.f.) in Central Lowlands of Nepal","authors":["Koirala, A.","Kizha, A. R.","Baral, S."],"year":2017,"venue":"Journal of Tropical Forestry and Environment","doi":"10.31357/jtfe.v7i1.3020","url":"https://doi.org/10.31357/jtfe.v7i1.3020","read_url":"https://web.archive.org/web/2024/http://journals.sjp.ac.lk/index.php/JTFE/article/download/3020/2093","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Teak stem volume from D and H (V5, generic)","output":{"quantity":"stem_volume"},"expression":"0.3364 + 0.0685 * D - 0.0970 * H","published":{"expression":"0.3364 + 0.0685 * dbh - 0.0970 * H","units":{"dbh":"cm","H":"m"},"variables":{"dbh":"D"},"output_unit":"m3"},"taxon":{"level":"species","name":"Tectona grandis","family":"Lamiaceae","group":"broadleaf"},"region":{"scope":"site","countries":["NP"],"place":"Sagarnath Forestry Development Project, Sarlahi district, central lowland Nepal","biomes":["tropical"]},"stand":"plantation","fit":{"n_trees":31,"dbh_min_cm":6.37,"dbh_max_cm":58.92,"h_min_m":5.7,"h_max_m":26.1,"r2":0.988,"method":"least squares on training set (31 of 44 felled trees)"},"evidence":[{"field":"expression","quote":"V = [0.3364 + (0.0685 × dbh) + (−0.097 × H)]","locator":"Abstract; Table 7, model V5"},{"field":"fit.n_trees","quote":"31 (70 % of the data) were randomly selected to build the model","locator":"Section 2.2"}],"check":[{"inputs":{"D":20,"H":12},"expected":0.5424,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":35,"H":19},"expected":0.8909,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":55,"H":24},"expected":1.7759,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"In the paper H is the height predicted from the H2 equation (H*), not the measured height; with measured height the fit is not what the authors validated. Stump excluded from volume. R2 0.988 (adj. 0.985), RMSE 0.09 m3 (Table 7). The only candidate with all parameters significant."}