Site-specific versus pantropical allometric equations: Which option to estimate the biomass of a moist central African forest?

• Published in: Forest ecology and management Vol. 312; pp. 1 - 9
• Main Authors: Ngomanda, Alfred, Engone Obiang, Nestor Laurier, Lebamba, Judicaël, Moundounga Mavouroulou, Quentin, Gomat, Hugues, Mankou, Géraud Sidoine, Loumeto, Joël, Midoko Iponga, Donald, Kossi Ditsouga, Franck, Zinga Koumba, Roland, Botsika Bobé, Karl Henga, Mikala Okouyi, Clency, Nyangadouma, Raoul, Lépengué, Nicaise, Mbatchi, Bertrand, Picard, Nicolas
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-01-2014; Elsevier
• Subjects: Aboveground woody biomass; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Carbon stock; Central Africa; Congo basin; Density; Foliage; Forestry; Forests; Fundamental and applied biological sciences. Psychology; Gabon; Mathematical analysis; Mathematical models; Pantropical equation; Plant allometry; Synecology; Terrestrial ecosystems; Trees; Congo Basin; Gabon; Central Africa; Sub-Saharan Africa; Africa; Aboveground woody biomass; Carbon stock; Gabon; Plant allometry; Pantropical equation; Congo basin; Forests; Tropical zone; Biomass; Allometry; Site specificity; Plant part; Humidity; Intertropical zone; Epigeal; Drainage basins; Forest ecology; Equation; Woody plant; River basins; Carbon; Forestry; Above ground plant part; Equatorial zone; Stock
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2013.10.029

•Existing pantropical biomass allometric equations do not rely on African data.•The biomass of 101 trees was destructively measured in northeastern Gabon.•New site-specific allometric equations were fitted to these data.•Chave et al. (2005) equations for moist forest overestimated the biomass by 40%.•More data on tree biomass are needed in central African moist forests.
Fewer data on tree biomass and allometric equations are available in African tropical moist forests than in the other tropical continents. When needing a biomass allometric equation, one thus faces the dilemma of using either a pantropical equation with the risk that it is biased for Africa, or a site-specific equation that is imprecise. Using a data set on aboveground biomass for 101 trees destructively measured at Zadié in northeastern Gabon, we fitted site-specific allometric equations and assessed the validity of ten existing equations. The best fitted model without height as a predictor was: B=exp[-4.0596+4.0624lnD-0.228(lnD)2+1.4307lnρ], whereas the best fitted model with height was: B=exp[-2.5680+0.9517ln(D2H)+1.1891lnρ], where B is the aboveground biomass in kg, D the diameter at breast height in cm, H the height in m, and ρ the wood density in gcm−3. Separate allometric equations for the stem, stump, foliage and branches were also fitted. Chave et al. (2005)’s pantropical equations for moist forests, that are currently the most commonly used allometric equations in central Africa, were not valid at Zadié with an overestimation of biomass of about 40%. The allometric equations of the same authors for wet forests were valid at Zadié, even though the climatic zone does not correspond. More data on tree biomass are needed in central Africa to explore the natural range of variability in tree biomass and identify the factors that influence variations among sites.