{"id":"de-cauwer-2020-vmer-d","source":{"id":"de-cauwer-2020","citation":"De Cauwer, V., Beeckman, H., Kleinn, C., Moses, M., Nott, A., Seifert, T., Muys, B. (2020). Improving the knowledge base for tropical dry forest management in southern Africa: Regional volume models for Pterocarpus angolensis. Forest Ecology and Management, 477, 118485.","title":"Improving the knowledge base for tropical dry forest management in southern Africa: Regional volume models for Pterocarpus angolensis","authors":["De Cauwer, V.","Beeckman, H.","Kleinn, C."],"year":2020,"venue":"Forest Ecology and Management","doi":"10.1016/j.foreco.2020.118485","url":"https://doi.org/10.1016/j.foreco.2020.118485","read_url":"https://lirias.kuleuven.be/retrieve/00adf4e9-cc77-4da0-88bc-0454a2f00a1c","access":"open","checked_at":"2026-11-02","status":"current","notes":"Read the author's copy on KU Leuven Lirias (carries the published article's page layout and tables). The candidate title in the queue is truncated; the full title names Pterocarpus angolensis."},"name":"Merchantable stem volume from DBH (Model 4, Table 7)","output":{"quantity":"stem_volume"},"expression":"exp(-7.533 + 0.896 * ln(D)^2 - 0.110 * ln(D)^3)","published":{"expression":"exp(-7.533 + 0.896 * ln(DBH)^2 - 0.110 * ln(DBH)^3)","units":{"DBH":"cm"},"variables":{"DBH":"D"},"output_unit":"m3"},"taxon":{"level":"species","name":"Pterocarpus angolensis","family":"Fabaceae","group":"broadleaf"},"region":{"scope":"regional","countries":["NA","AO"],"place":"Baikiaea-Pterocarpus woodlands of northern Namibia and southern Angola (MAP 480-700 mm)","biomes":["tropical","dryland"]},"stand":"natural","fit":{"n_trees":356,"dbh_min_cm":5,"dbh_max_cm":92,"r2":0.92,"method":"Regression on ln scale with Baskerville correction in intercept; adjusted R2"},"evidence":[{"field":"expression","quote":"Vmer = exp(a + b 1 *(lnDBH)2 + b 2 *(lnDBH)3 ... -7.533 *** 0.896 *** -0.110 ***","locator":"Table 7, Model 4"},{"field":"fit.n_trees","quote":"Data of 340 trees were used for Model 6 and 356 trees for all other models. DBH range is between 5 and 92 cm.","locator":"Table 7 caption"}],"check":[{"inputs":{"D":20},"expected":0.0863566,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":50},"expected":0.666105,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Merchantable (saw wood) over-bark volume of the bole, excluding the stump; the bole is the stem up to the first branch, so mapped to stem_volume. Table 7 caption: intercept a includes the Baskerville correction factor, so nothing is added (no CF value printed). Quadratic and cubic terms of ln(DBH) as printed. Paper's RSE is on the volume scale (m3), so fit.rse is left out; R2 is the printed adjusted R2."}