{"id":"thapa-2013-h-power","source":{"id":"thapa-2013","citation":"Thapa, T. B., Upadhyaya, C. P., Timilsina, Y. P., Bhandari, S. K., & Puri, L. (2013). Predicting total height from diameter using nonlinear models in Pinus roxburghii. Nepal Journal of Science and Technology, 14(1), 147–152.","title":"Predicting Total Height from Diameter Using Nonlinear Models in Pinus roxburghii","authors":["Thapa, T. B.","Upadhyaya, C. P.","Timilsina, Y. P."],"year":2013,"venue":"Nepal Journal of Science and Technology","doi":"10.3126/njst.v14i1.8935","url":"https://doi.org/10.3126/njst.v14i1.8935","read_url":"https://www.nepjol.info/index.php/NJST/article/download/8935/7338","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Chir pine height from D (M1, power)","output":{"quantity":"height"},"expression":"exp(-0.276) * D^0.925","published":{"expression":"exp(-0.276) * DBH^0.925","units":{"DBH":"cm"},"variables":{"DBH":"D"},"output_unit":"m"},"taxon":{"level":"species","name":"Pinus roxburghii","family":"Pinaceae","group":"conifer"},"region":{"scope":"site","countries":["NP"],"place":"Galeshwor Thulo Salleri and Banchare Dil community forests, Ghatan VDC, Myagdi district, west Nepal","biomes":["subtropical","montane"]},"stand":"natural","fit":{"n_trees":180,"dbh_min_cm":5.57,"dbh_max_cm":61.94,"h_min_m":2.5,"h_max_m":35,"r2":0.91,"method":"nonlinear least squares, H = exp(b0) D^b1 (R2 adj. reported)"},"evidence":[{"field":"expression","quote":"M1 i.e. H = e(-0.276) D0.925 is considered best fitted model","locator":"Results and Discussion, p. 150"},{"field":"fit.n_trees","quote":"Total height and diameter at breast height of 180 trees were measured","locator":"Abstract"},{"field":"fit.r2","quote":"R2 adj.=0.910","locator":"Abstract; Table 3, M1"},{"field":"fit.dbh_min_cm","quote":"Minimum 5.57 ... Maximum 61.94","locator":"Table 1, Diameter (cm) rows (smallest minimum and largest maximum across the six diameter classes)"}],"check":[{"inputs":{"D":10},"expected":6.3846,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":25},"expected":14.9015,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":50},"expected":28.2932,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"r2 is the adjusted R2 as printed. RMSE 1.221 (Table 3). Models M2-M5 are printed in Table 3 with parameters rounded (several show -0.000), so only the selected M1 is recorded. 30 trees per diameter class, 6 classes."}