Variation in wood density determines spatial patterns inAmazonian forest biomass

作者：Timothy R. Baker, Oliver L. Phillips, Yadvinder Malhi, Samuel Almeida, Luzmila Arroyo, Anthony Di Fiore, Terry L. Erwin, Timothy J. Killeen, Susan G. W. Laurance, William F. Laurance, Simon L. Lewis, Jon Lloyd, Abel Monteagudo, David Neill, Sandra Patiño, Nigel C. A. Pitman, José Natalino Macedo Silva, Rodolfo Vásquez Martínez · 发表于：Global Change Biology · 年份：2004 · DOI：10.1111/j.1365-2486.2004.00751.x · 被引用次数：815 · 研究领域：Forest ecology and management、Ecology and Vegetation Dynamics Studies、Plant Water Relations and Carbon Dynamics

Abstract Uncertainty in biomass estimates is one of the greatest limitations to models of carbon flux in tropical forests. Previous comparisons of field‐based estimates of the aboveground biomass (AGB) of trees greater than 10 cm diameter within Amazonia have been limited by the paucity of data for western Amazon forests, and the use of site‐specific methods to estimate biomass from inventory data. In addition, the role of regional variation in stand‐level wood specific gravity has not previously been considered. Using data from 56 mature forest plots across Amazonia, we consider the relative roles of species composition (wood specific gravity) and forest structure (basal area) in determining variation in AGB. Mean stand‐level wood specific gravity, on a per stem basis, is 15.8% higher in forests in central and eastern, compared with northwestern Amazonia. This pattern is due to the higher diversity and abundance of taxa with high specific gravity values in central and eastern Amazonia, and the greater diversity and abundance of taxa with low specific gravity values in western Amazonia. For two estimates of AGB derived using different allometric equations, basal area explains 51.7% and 63.4%, and stand‐level specific gravity 45.4% and 29.7%, of the total variation in AGB. The variation in specific gravity is important because it determines the regional scale, spatial pattern of AGB. When weighting by specific gravity is included, central and eastern Amazon forests have signif...