{"id":"owate-2018-agb-poly","source":{"id":"owate-2018","citation":"Owate, O.A., Mware, M.J., Kinyanjui, M.J. (2018). Allometric Equations for Estimating Silk Oak (Grevillea robusta) Biomass in Agricultural Landscapes of Maragua Subcounty, Kenya. International Journal of Forestry Research, 2018, 6495271.","title":"Allometric Equations for Estimating Silk Oak (Grevillea robusta) Biomass in Agricultural Landscapes of Maragua Subcounty, Kenya","authors":["Owate, O.A.","Mware, M.J.","Kinyanjui, M.J."],"year":2018,"venue":"International Journal of Forestry Research","doi":"10.1155/2018/6495271","url":"https://doi.org/10.1155/2018/6495271","read_url":"https://onlinelibrary.wiley.com/doi/full/10.1155/2018/6495271","access":"open","license":"CC BY 4.0","checked_at":"2026-11-01","status":"current"},"name":"Grevillea robusta on farms, polynomial in DBH (selected model)","output":{"quantity":"agb"},"expression":"0.248 * D^2 + 6.243 * D - 15.45","published":{"expression":"0.248 * DBH^2 + 6.243 * DBH - 15.45","units":{"DBH":"cm"},"variables":{"DBH":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Grevillea robusta","family":"Proteaceae","group":"broadleaf"},"region":{"scope":"site","countries":["KE"],"place":"Maragua subcounty, Murang'a County, central Kenya (farms)","biomes":["tropical"]},"stand":"agroforestry","fit":{"n_trees":33,"dbh_min_cm":1.5,"dbh_max_cm":29.8,"h_min_m":3.6,"h_max_m":24.8,"r2":0.94,"method":"polynomial regression on untransformed data"},"evidence":[{"field":"expression","quote":"AGB=0.248DBH2 + 6.243DBH – 15.45","locator":"Table 7"},{"field":"fit.n_trees","quote":"33","locator":"Appendix Table 10 (trees 1-33)"}],"check":[{"inputs":{"D":15},"expected":134,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":28},"expected":353.79,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-01","notes":"Selected by the authors. Returns negative AGB below about 2.3 cm DBH, inside the fitted range; use owate-2018-agb-power for trees that small. the authors say the trees do not grow beyond 40 cm DBH and the model should not be applied to larger trees. DBH range from Appendix Table 10."}