Helene C. Muller-Landau, University of Minnesota Twin Cities
Richard S. Condit, Smithsonian Tropical Research Institute
Kyle E. Harms, Smithsonian Tropical Research Institute
Christian O. Marks, University of Minnesota Twin Cities
Sean C. Thomas, University of Toronto
Sarayudh Bunyavejchewin, National Park, Wildlife and Plant Conservation Department, Thailand
George Chuyong, University of Buea
Leonardo Co, University of the Philippines Diliman
Stuart Davies, Smithsonian Tropical Research Institute
Robin Foster, Field Museum of Natural History
Savitri Gunatilleke, University of Peradeniya
Nimal Gunatilleke, University of Peradeniya
Terese Hart, Wildlife Conservation Society
Stephen P. Hubbell, Smithsonian Tropical Research Institute
Akira Itoh, Osaka City University
Abd Rahman Kassim, Forest Research Institute Malaysia
David Kenfack, University of Missouri-St. Louis
James V. LaFrankie, Nanyang Technological University
Daniel Lagunzad, University of the Philippines Diliman
Hua Seng Lee, Forest Department Sarawak
Elizabeth Losos, Duke University
Jean Remy Makana, Wildlife Conservation Society
Tatsuhiro Ohkubo, Utsunomiya University
Cristian Samper, Smithsonian National Museum of Natural History
Raman Sukumar, Indian Institute of Science, Bengaluru
I. Fang Sun, Center for Tropical Ecology and Biodiversity
M. N. Nur Supardi, Forest Research Institute Malaysia
Sylvester Tan, Forest Research Centre - Sandakan
Duncan Thomas, Oregon State University
Jill Thompson, University of Puerto Rico, Institute for Tropical Ecosystem Studies
Renato Valencia, Pontificia Universidad Catolica del Ecuador
Martha Isabel Vallejo, Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogota
Gorky Villa Muñoz, Pontificia Universidad Catolica del Ecuador

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Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and > 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality. © 2006 Blackwell Publishing Ltd/CNRS.

Publication Source (Journal or Book title)

Ecology Letters

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