Articles | Volume 6, issue 11
Biogeosciences, 6, 2719–2731, 2009

Special issue: Biogeochemistry and function of Amazon Forest

Biogeosciences, 6, 2719–2731, 2009

  30 Nov 2009

30 Nov 2009

Multi-scale comparisons of tree composition in Amazonian terra firme forests

E. N. Honorio Coronado1,4, T. R. Baker2, O. L. Phillips2, N. C. A. Pitman3, R. T. Pennington4, R. Vásquez Martínez5, A. Monteagudo2, H. Mogollón6, N. Dávila Cardozo7, M. Ríos7, R. García-Villacorta7, E. Valderrama7, M. Ahuite7, I. Huamantupa5, D. A. Neill8, W. F. Laurance9, H. E. M. Nascimento9,10, S. Soares de Almeida11, T. J. Killeen12, L. Arroyo13, P. Núñez14, and L. Freitas Alvarado1 E. N. Honorio Coronado et al.
  • 1Instituto de Investigaciones de la Amazonía Peruana, Av. A. José Quiñones km 2.5, Iquitos, Peru
  • 2Earth and Biosphere Institute, School of Geography, University of Leeds, Leeds, UK
  • 3Center for Tropical Conservation, Duke University, Durham, USA
  • 4Royal Botanic Garden Edinburgh, 20a Inverleith Row, Edinburgh EH3 5LR, UK
  • 5Proyecto Flora del Perú, Jardín Botánico de Missouri, Oxapampa, Peru
  • 6Finding Species, 6930 Carroll Ave., Suite 600, P.O. Box 5289, Takoma Park, MD 20912, USA
  • 7Facultad de Ciencias Biológicas, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
  • 8Missouri Botanical Garden, c/o Naturaleza y Cultura Internacional, Loja, Ecuador
  • 9Smithsonian Tropical Research Institute, Balboa, Panama
  • 10Biological Dynamics of Forest Fragments Project, Manaus, Brazil
  • 11Museu Paraense Emilio Goeldi, 66.040170 Belém, Pará, Brazil
  • 12Center for Applied Biodiversity Science, Conservation International, Washington D.C., USA
  • 13Museo Noel Kempff Mercado, Santa Cruz, Bolivia
  • 14Herbario Vargas, Universidad Nacional San Antonio Abad del Cusco, Cusco, Peru

Abstract. We explored the floristic composition of terra firme forests across Amazonia using 55 plots. Firstly, we examined the floristic patterns using both genus- and species-level data and found that the species-level analysis more clearly distinguishes among forests. Next, we compared the variation in plot floristic composition at regional- and continental-scales, and found that average among-pair floristic similarity and its decay with distance behave similarly at regional- and continental-scales. Nevertheless, geographical distance had different effects on floristic similarity within regions at distances <100 km, where north-western and south-western Amazonian regions showed greater floristic variation than plots of central and eastern Amazonia. Finally, we quantified the role of environmental factors and geographical distance for determining variation in floristic composition. A partial Mantel test indicated that while geographical distance appeared to be more important at continental scales, soil fertility was crucial at regional scales within western Amazonia, where areas with similar soil conditions were more likely to share a high number of species. Overall, these results suggest that regional-scale variation in floristic composition can rival continental-scale differences within Amazonian terra firme forests, and that variation in floristic composition at both scales is influenced by geographical distance and environmental factors, such as climate and soil fertility. To fully account for regional-scale variation in continental studies of floristic composition, future floristic studies should focus on forest types poorly represented at regional scales in current datasets, such as terra firme forests with high soil fertility in north-western Amazonia.

Final-revised paper