{"id":"mugasha-2016-volume-general-m7","source":{"id":"mugasha-2016","citation":"Mugasha, W.A., Mwakalukwa, E.E., Luoga, E., et al. (2016). Allometric Models for Estimating Tree Volume and Aboveground Biomass in Lowland Forests of Tanzania. International Journal of Forestry Research, 2016, 8076271.","title":"Allometric Models for Estimating Tree Volume and Aboveground Biomass in Lowland Forests of Tanzania","authors":["Mugasha, W.A.","Mwakalukwa, E.E.","Luoga, E."],"year":2016,"venue":"International Journal of Forestry Research","doi":"10.1155/2016/8076271","url":"https://doi.org/10.1155/2016/8076271","read_url":"https://onlinelibrary.wiley.com/doi/10.1155/2016/8076271","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Tanzania lowland forest, Dindili and Rondo combined, total volume, D only (model 7)","output":{"quantity":"total_volume"},"expression":"-0.0393 + 0.00102 * D^2","published":{"expression":"-0.0393 + 0.00102 * DBH^2","units":{"DBH":"cm"},"variables":{"DBH":"D"},"output_unit":"m3"},"taxon":{"level":"mixed","name":"Mixed lowland forest tree species","group":"broadleaf"},"region":{"scope":"regional","countries":["TZ"],"place":"Dindili (Morogoro) and Rondo (Lindi) lowland forests, Tanzania","biomes":["tropical"]},"stand":"natural","fit":{"n_trees":60,"r2":0.95,"method":"maximum-likelihood non-linear regression with variance function"},"evidence":[{"field":"expression","quote":"Total tree volume General 7 −0.0393 0.00102 — 0.013 × dbh0.5 0.85 0.95 92.06","locator":"Table 3 (columns: a, b, c, error, RMSE, R2, AIC)"},{"field":"published.units","quote":"where Y is the volume (m3 tree−1) or biomass (kg tree−1); WD is wood basic density (g cm−3); a, b, and c are model parameters to be estimated.","locator":"Section 2.6.2"},{"field":"fit.n_trees","quote":"A total of 30 trees were selected from each site","locator":"Section 2.3"}],"check":[{"inputs":{"D":20},"expected":0.3687,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":50},"expected":2.5107,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Fitted by maximum-likelihood non-linear regression with a variance function, no back-transformation. Table 3 column \"R2\" is stored as r2. Total volume is stem plus branches. Table 3 prints the model forms (6)-(10) as images; they were read from the rendered equations. Model (7) is Y = a + b × dbh²."}