{"id":"du-2026-oak-root","source":{"id":"du-2026","citation":"Du, Z., Liu, Z., Wang, J., Zou, Z., He, W., Zeng, W., Meng, J., & Chen, Z. (2026). Development of Compatible Biomass Models for Chinese Fir, Poplar, and Oak in Hunan Province. Forests, 17(7), 770.","title":"Development of Compatible Biomass Models for Chinese Fir, Poplar, and Oak in Hunan Province","authors":["Du, Z.","Liu, Z.","Wang, J."],"year":2026,"venue":"Forests","doi":"10.3390/f17070770","url":"https://doi.org/10.3390/f17070770","read_url":"https://www.mdpi.com/1999-4907/17/7/770/pdf?version=1782822414","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current"},"name":"Oak root biomass (compatible total-biomass system)","output":{"quantity":"bgb"},"expression":"0.018969 * (D^2 * H)^0.89162","published":{"expression":"0.018969 * (D^2 * H)^0.89162","units":{"D":"cm","H":"m"},"output_unit":"kg"},"taxon":{"level":"genus","name":"Quercus","family":"Fagaceae","group":"broadleaf"},"region":{"scope":"regional","countries":["CN"],"place":"Hunan Province (14 prefecture-level cities and autonomous prefectures)","biomes":["subtropical"]},"stand":"mixed","fit":{"n_trees":50,"r2":0.7778,"method":"weighted nonlinear least squares"},"evidence":[{"field":"fit.n_trees","quote":"Oak 157 (50) (Total Samples (Root Samples))","locator":"Table 1"},{"field":"expression","quote":"Broot = 0.018969 (D 2 H) 0.89162 (37)","locator":"Table 10, Eq. 35-37"},{"field":"fit.r2","quote":"(28) * 0.7778 23.78 −0.80 14.34 47.64 85.29","locator":"Table 13, row (28) * (root model evaluated on the trees with measured root samples)"}],"check":[{"inputs":{"D":10,"H":9},"expected":8.1678,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":30,"H":20},"expected":118.07,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Final root model of the compatible system, fitted on trees with root samples (n from Table 1). Compatible total-biomass system (aboveground fitted independently, total and root fitted jointly by simultaneous estimation; weighted nonlinear least squares). Total = aboveground + root. The paper lists the sample as stratified random felled trees across eight diameter classes (4-32 cm) from 2022-2023; the reported minimum and maximum DBH and height are for all sampled trees of the species (Table 1). Root biomass was measured on a subset only (whole-root excavation: root collar, coarse roots, fine roots), so root and total fit ranges are not given beyond the full sample. No back-transform factor (nonlinear fit). The paper also gives aboveground-component (stem, crown, wood, bark, branch, foliage) systems (Tables 17-39), not added here. Eq. 37 and Table 10 print the same parameters. R² is the evaluation row marked * (the 50 trees with measured roots, matching n_trees; the paper's Discussion cites these starred values as the root-model R²); the unstarred row (0.8592) is evaluated over all sampled trees, most of which have no measured roots."}