{"id":"wangui-2026-agb-pittosporum-crassifolium-massey-d-h","source":{"id":"wangui-2026","citation":"Wangui, J. C., Pain, S. J., Kenyon, P. R., Tozer, P. R., & Millner, J. P. (2026). Biomass and carbon estimation for three browsable native shrubs in New Zealand. New Zealand Journal of Forestry Science, 56, 16.","title":"Biomass and carbon estimation for three browsable native shrubs in New Zealand","authors":["Wangui, J. C.","Pain, S. J.","Kenyon, P. R."],"year":2026,"venue":"New Zealand Journal of Forestry Science","doi":"10.33494/nzjfs562026x567x","url":"https://doi.org/10.33494/nzjfs562026x567x","read_url":"https://nzjforestryscience.nz/index.php/nzjfs/article/download/567/153","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Pittosporum crassifolium (Massey University): AGB from D and H (Table 7)","output":{"quantity":"agb"},"expression":"1.0 * exp(-3.65 + 3.93 * ln(DRC) + -2.4 * ln(H))","published":{"expression":"1.0 * exp(-3.65 + 3.93 * ln(D) + -2.4 * ln(H))","units":{"D":"cm","H":"m"},"variables":{"D":"DRC"},"output_unit":"kg"},"taxon":{"level":"species","name":"Pittosporum crassifolium","family":"Pittosporaceae","group":"shrub"},"region":{"scope":"regional","countries":["NZ"],"place":"Massey University natural reserves and Dairy4 farm trial site","biomes":["temperate"]},"stand":"mixed","fit":{"n_trees":5,"cf":1,"method":"OLS regression on natural logarithms (power form), back-transformed with correction factor CF = exp(RSE^2/2)"},"evidence":[{"field":"expression","quote":"P. crassifolium Massey University ln(AGB) =ln (a)+b×ln(D)+c×ln(H) -3.65*** 3.93** -2.40* … CF 1.00","locator":"Table 7"},{"field":"fit.cf","quote":"CF = e(RSE²/2)  Equation 2; Table 7 CF column 1.0","locator":"Methods, Equation 2; Table 7"}],"check":[{"inputs":{"DRC":2,"H":1},"expected":0.3962,"origin":"computed","note":"computed from the published form (a is ln(a), CF applied, coefficients as printed)"},{"inputs":{"DRC":4,"H":2},"expected":1.1441,"origin":"computed","note":"computed from the published form (a is ln(a), CF applied, coefficients as printed)"},{"inputs":{"DRC":8,"H":3},"expected":6.5899,"origin":"computed","note":"computed from the published form (a is ln(a), CF applied, coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"AGB is the sum of stem, branch and foliage dry biomass of the shrub. Natural log. D is the basal stem diameter over bark about 10 cm above ground (multi-stemmed shrubs: square root of the sum of stem diameters), mapped to DRC; H is total height in m. Table 7 reports adjusted R2 = 0.996 and RMSE = 0.038 (not used as r2 or rse). Shrubs had basal diameter up to 10 cm (mean D 3.4 to 3.8 cm by species, Table 4); the paper prints no D range for these models. The CF column is the factor the paper applies to back-transformed predictions."}