Articles | Volume 6, issue 4
Biogeosciences, 6, 545–568, 2009

Special issue: Biogeochemistry and function of Amazon Forest

Biogeosciences, 6, 545–568, 2009

  08 Apr 2009

08 Apr 2009

Branch xylem density variations across the Amazon Basin

S. Patiño1,2,*, J. Lloyd2, R. Paiva3,**, T. R. Baker2,*, C. A. Quesada2,3, L. M. Mercado4,*, J. Schmerler5,*, M. Schwarz5,*, A. J. B. Santos6,†, A. Aguilar1, C. I. Czimczik7,*, J. Gallo8, V. Horna9,*, E. J. Hoyos10, E. M. Jimenez1, W. Palomino11, J. Peacock2, A. Peña-Cruz12, C. Sarmiento13, A. Sota5,*, J. D. Turriago8, B. Villanueva8, P. Vitzthum1, E. Alvarez14, L. Arroyo15, C. Baraloto13, D. Bonal13, J. Chave16, A. C. L. Costa17, R. Herrera*, N. Higuchi3, T. Killeen18, E. Leal19, F. Luizão3, P. Meir20, A. Monteagudo11,12, D. Neil21, P. Núñez-Vargas11, M. C. Peñuela1, N. Pitman22, N. Priante Filho23, A. Prieto24, S. N. Panfil25, A. Rudas26, R. Salomão19, N. Silva27,28, M. Silveira29, S. Soares deAlmeida19, A. Torres-Lezama30, R. Vásquez-Martínez11, I. Vieira19, Y. Malhi31, and O. L. Phillips2,*** S. Patiño et al.
  • 1Grupo de Ecología de Ecosistemas Terrestres Tropicales, Universidad Nacional de Colombia, Sede Amazonia, Instituto Amazónico de Investigaciones-Imani, km. 2, vía Tarapacá, Leticia, Amazonas, Colombia
  • 2Earth and Biosphere Institute, School of Geography, University of Leeds, LS2 9JT, England, UK
  • 3Institito National de Pesquisas Amazônicas, Manaus, Brazil
  • 4Centre for Ecology and Hydrology, Wallingford, England, UK
  • 5Fieldwork Assistance, Postfach 101022, 07710 Jena, Germany
  • 6Departamento de Ecologia, Universidade de Brasília, Brazil
  • 7Department of Earth System Science, University of California, Irvine, USA
  • 8Departamento de Biología, Universidad Distrital, Bogotá, Colombia
  • 9Abteilung Ökologie und Ökosystemforschung, Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Universität Göttingen, Göttingen, Germany
  • 10Departamento de Ciencias Forestales, Universidad Nacional de Colombia, Medellín, Colombia
  • 11Herbario Vargas, Universidad Nacional San Antonio Abad del Cusco, Cusco, Perú
  • 12Proyecto Flora del Perú, Jardín Botánico de Missouri, Oxapampa, Perú
  • 13UMR-ECOFOG, INRA, 97310 Kourou, French Guiana
  • 14Equipo de Gestión Ambiental, Interconexión Eléctrica S.A. ISA., Medellín, Colombia
  • 15Museo Noel Kempff Mercado, Santa Cruz, Bolivia
  • 16Lab. Evolution et Diversité' Biologique CNRS, Univ. Paul Sabatier Bâtiment 4R3, 31062, Toulouse cedex 4, France
  • 17Universidade Federal de Pará, Belem, Brazil
  • 18Center for Applied Biodiversity Science, Conservation International, Washington, DC, USA
  • 19Museu Paraense Emilio Goeldi, Belem, Brazil
  • 20School of Geography, University of Edinburgh, Edinburgh, Scotland, UK
  • 21Herbario Nacional del Ecuador, Quito, Ecuador
  • 22Center for Tropical Conservation, Duke University, Durham, USA
  • 23Universidade Federal do Mato Grosso, Cuiaba, Brazil
  • 24Instituto de Investigación de Recursos Biológicos Alexander von Humboldt. Diagonal 27 No. 15-09, Bogotá D.C, Colombia
  • 25Department of Botany, University of Georgia, Athens, USA
  • 26Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá, Colombia
  • 27CIFOR, Tapajos, Brazil
  • 28EMBRAPA Amazonia Oriental, Belem, Brazil
  • 29Departamento de Ciências da Natureza, Universidade Federal do Acre, Rio Branco, Brazil
  • 30Facultad de Ciencias Forestales y Ambiental, Universidad de Los Andes, Mérida, Venezuela
  • 31Oxford University, Centre for the Environment, Oxford, England, United Kingdom
  • deceased
  • *formerly at: Max-Planck-Institut für Biogeochemie, Jena, Germany
  • **now at: Secretária Municipal de Desenvolvimento e Meio Ammbiente ma Prefeturia Municipal de Maués, Maués, Brazil
  • ***Authors are listed according to their contribution to the work.

Abstract. Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρx, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m−3 for a Cordia sagotii (Boraginaceae) from Mountagne de Tortue, French Guiana to 1130 kg m−3 for an Aiouea sp. (Lauraceae) from Caxiuana, Central Pará, Brazil. Analysis of variance showed significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species) accounted for 33% with environment (geographic location and plot) accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.

Final-revised paper