Articles | Volume 6, issue 2
Biogeosciences, 6, 297–307, 2009

Special issue: Biogeochemistry and function of Amazon Forest

Biogeosciences, 6, 297–307, 2009

  25 Feb 2009

25 Feb 2009

Do species traits determine patterns of wood production in Amazonian forests?

T. R. Baker1, O. L. Phillips1, W. F. Laurance2, N. C. A. Pitman3, S. Almeida4, L. Arroyo5, A. DiFiore6, T. Erwin7, N. Higuchi8, T. J. Killeen9, S. G. Laurance2, H. Nascimento10, A. Monteagudo11, D. A. Neill12, J. N. M. Silva13,14, Y. Malhi15, G. López Gonzalez1, J. Peacock1, C. A. Quesada1, S. L. Lewis1, and J. Lloyd1 T. R. Baker et al.
  • 1Earth and Biosphere Institute, School of Geography, University of Leeds, Leeds, UK
  • 2Smithsonian Tropical Research Institute, Balboa, Panama
  • 3Center for Tropical Conservation, Duke University, Durham, USA
  • 4Museu Paraense Emilio Goeldi, Belém, Brazil
  • 5Museo Noel Kempff Mercado, Santa Cruz, Bolivia
  • 6Department of Anthropology, New York University, NY, USA
  • 7Smithsonian Institution, Washington DC, USA
  • 8Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil
  • 9Center for Applied Biodiversity Science, Conservation International, Washington DC, USA
  • 10Biological Dynamics of Forest Fragments Project, Manaus, Brazil
  • 11Proyecto Flora del Perú, Jardin Botanico de Missouri, Oxapampa, Perú
  • 12Missouri Botanical Garden, c/o Naturaleza y Cultura Internacional, Loja, Ecuador
  • 13Center for International Forestry Research, Tapajos, Brazil
  • 14EMBRAPA Amazonia Oriental, Belém, Brazil
  • 15Oxford University Centre for the Environment, Oxford, UK

Abstract. Understanding the relationships between plant traits and ecosystem properties at large spatial scales is important for predicting how compositional change will affect carbon cycling in tropical forests. In this study, we examine the relationships between species wood density, maximum height and above-ground, coarse wood production of trees ≥10 cm diameter (CWP) for 60 Amazonian forest plots. Average species maximum height and wood density are lower in Western than Eastern Amazonia and are negatively correlated with CWP. To test the hypothesis that variation in these traits causes the variation in CWP, we generate plot-level estimates of CWP by resampling the full distribution of tree biomass growth rates whilst maintaining the appropriate tree-diameter and functional-trait distributions for each plot. These estimates are then compared with the observed values. Overall, the estimates do not predict the observed, regional-scale pattern of CWP, suggesting that the variation in community-level trait values does not determine variation in coarse wood productivity in Amazonian forests. Instead, the regional gradient in CWP is caused by higher biomass growth rates across all tree types in Western Amazonia. Therefore, the regional gradient in CWP is driven primarily by environmental factors, rather than the particular functional composition of each stand. These results contrast with previous findings for forest biomass, where variation in wood density, associated with variation in species composition, is an important driver of regional-scale patterns in above-ground biomass. Therefore, in tropical forests, above-ground wood productivity may be less sensitive than biomass to compositional change that alters community-level averages of these plant traits.

Final-revised paper