title: Improved allometric models to estimate the aboveground biomass of tropical trees.
abstract: Terrestrial carbon stock mapping is important for the successful implementation of climate change mitigation policies. Its accuracy depends on the availability of reliable allometric models to infer oven-dry aboveground biomass of trees from census data. The degree of uncertainty associated with previously published pantropical aboveground biomass allometries is large. We analyzed a global database of directly harvested trees at 58 sites, spanning a wide range of climatic conditions and vegetation types (4004 trees ≥ 5 cm trunk diameter). When trunk diameter, total tree height, and wood specific gravity were included in the aboveground biomass model as covariates, a single model was found to hold across tropical vegetation types, with no detectable effect of region or environmental factors. The mean percent bias and variance of this model was only slightly higher than that of locally fitted models. Wood specific gravity was an important predictor of aboveground biomass, especially when including a much broader range of vegetation types than previous studies. The generic tree diameter-height relationship depended linearly on a bioclimatic stress variable E, which compounds indices of temperature variability, precipitation variability, and drought intensity. For cases in which total tree height is unavailable for aboveground biomass estimation, a pantropical model incorporating wood density, trunk diameter, and the variable E outperformed previously published models without height. However, to minimize bias, the development of locally derived diameter-height relationships is advised whenever possible. Both new allometric models should contribute to improve the accuracy of biomass assessment protocols in tropical vegetation types, and to advancing our understanding of architectural and evolutionary constraints on woody plant development.
authors.affiliation: UMR 5174 Laboratoire Evolution et Diversité Biologique, CNRS & Université Paul Sabatier, Toulouse, 31062, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Chave
authors.forename: Maxime
authors.initials: M
authors.lastname: Réjou-Méchain
authors.forename: Alberto
authors.initials: A
authors.lastname: Búrquez
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chidumayo
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Colgan
authors.forename: Welington B C
authors.initials: WB
authors.lastname: Delitti
authors.forename: Alvaro
authors.initials: A
authors.lastname: Duque
authors.forename: Tron
authors.initials: T
authors.lastname: Eid
authors.forename: Philip M
authors.initials: PM
authors.lastname: Fearnside
authors.forename: Rosa C
authors.initials: RC
authors.lastname: Goodman
authors.forename: Matieu
authors.initials: M
authors.lastname: Henry
authors.forename: Angelina
authors.initials: A
authors.lastname: Martínez-Yrízar
authors.forename: Wilson A
authors.initials: WA
authors.lastname: Mugasha
authors.forename: Helene C
authors.initials: HC
authors.lastname: Muller-Landau
authors.forename: Maurizio
authors.initials: M
authors.lastname: Mencuccini
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Nelson
authors.forename: Alfred
authors.initials: A
authors.lastname: Ngomanda
authors.forename: Euler M
authors.initials: EM
authors.lastname: Nogueira
authors.forename: Edgar
authors.initials: E
authors.lastname: Ortiz-Malavassi
authors.forename: Raphaël
authors.initials: R
authors.lastname: Pélissier
authors.forename: Pierre
authors.initials: P
authors.lastname: Ploton
authors.forename: Casey M
authors.initials: CM
authors.lastname: Ryan
authors.forename: Juan G
authors.initials: JG
authors.lastname: Saldarriaga
authors.forename: Ghislain
authors.initials: G
authors.lastname: Vieilledent
mesh_terms: D018533:Biomass; D002244:Carbon; D004784:Environmental Monitoring / Q000379:methods*; D008954:Models, Biological; D008962:Models, Theoretical; D012044:Regression Analysis; D013046:Specific Gravity; D014197:Trees / Q000502:physiology*; D014329:Tropical Climate; D014934:Wood / Q000737:chemistry
chemical_list: D002244:Carbon
keywords: carbon; forest inventory; global carbon cycling; plant allometry; tree height; tropics