{"id":"koirala-2017-h-log","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 height from D (H2, logarithmic)","output":{"quantity":"height"},"expression":"-5.2544 + 6.8603 * ln(D)","published":{"expression":"-5.2544 + 6.8603 * ln(dbh)","units":{"dbh":"cm"},"variables":{"dbh":"D"},"output_unit":"m"},"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":0.928,"method":"least squares on training set (31 of 44 felled trees)"},"evidence":[{"field":"expression","quote":"H = [− 5.2544 + (6.8603 × ln (dbh))]","locator":"Abstract; Table 5, model H2"},{"field":"fit.n_trees","quote":"31 (70 % of the data) were randomly selected to build the model","locator":"Section 2.2"},{"field":"fit.dbh_min_cm","quote":"dbh (cm) 6.37 58.92; H (m) 5.70 26.10","locator":"Table 3, training data set"}],"check":[{"inputs":{"D":10},"expected":10.542,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":30},"expected":18.0788,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":55},"expected":22.2371,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"H is total height excluding the 0.10 m stump. R2 0.928 (adj. 0.921), RMSE 1.46 printed in Table 5. Selected as best height-diameter model by the authors."}