{"id":"rohling-2019-bgb-oak","source":{"id":"rohling-2019","citation":"Röhling, S., Demant, B., Dunger, K., Neubauer, M., Oehmichen, K., Riedel, T., & Stümer, W. (2019). Equations for estimating belowground biomass of Silver Birch, Oak and Scots Pine in Germany. iForest, 12, 166-172.","title":"Equations for estimating belowground biomass of Silver Birch, Oak and Scots Pine in Germany","authors":["Röhling, S.","Demant, B.","Dunger, K."],"year":2019,"venue":"iForest - Biogeosciences and Forestry","doi":"10.3832/ifor2862-012","url":"https://doi.org/10.3832/ifor2862-012","read_url":"https://iforest.sisef.org/pdf/?id=ifor2862-012","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Quercus robur and Q. petraea, Germany, belowground biomass from DBH (Eq. 4, Tab. 1)","output":{"quantity":"bgb"},"expression":"0.040113 * D^2.227842","published":{"expression":"0.040113 * DBH^2.227842","units":{"DBH":"cm"},"variables":{"DBH":"D"},"output_unit":"kg"},"taxon":{"level":"genus","name":"Quercus (Q. robur and Q. petraea pooled)","family":"Fagaceae","group":"broadleaf","members":["Quercus robur","Quercus petraea"],"members_complete":true},"region":{"scope":"regional","countries":["DE"],"place":"20 forest stands in Brandenburg, Saxony-Anhalt and Thuringia, Germany","biomes":["temperate"]},"stand":"mixed","fit":{"n_trees":39,"dbh_min_cm":7.4,"dbh_max_cm":42,"method":"weighted (1/DBH²) nonlinear least squares power function"},"evidence":[{"field":"expression","quote":"BGB = β1 · DBH^β2; Oak β1 0.040113 (0.0253-0.0548), β2 2.227842 (2.1179-2.3377), ME 0.98, RMSE 5.2","locator":"Eq. 4 and Tab. 1, p. 168"},{"field":"fit.n_trees","quote":"48 Birches, 39 Oaks and 54 Pines were sampled","locator":"Material and methods, Study sites, p. 167"},{"field":"fit.dbh_max_cm","quote":"DBH ranged from 7.2 up to 53.2 cm for Pine, from 7.4 to 42.0 cm for Oak and from 8.2 to 52.9 cm for Birch","locator":"Study sites, pp. 167-168"}],"check":[{"inputs":{"D":10},"expected":6.7784,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":25},"expected":52.2,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":40},"expected":148.74,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Dry mass of coarse roots (2 mm and thicker) including the belowground stump; fine roots excluded. Units not printed beside Tab. 1 but BGB is reported in kg and DBH in cm throughout the paper. The paper gives model efficiency (ME) and RMSE, not R², so none is recorded."}