Phylogenetic diversity metrics for ecological communities: integrating species richness, abundance and evolutionary history

Authors

  • Marc W. Cadotte,

    Corresponding author
    1. National Center for Ecological Analysis and Synthesis, University of California, 735 State St., Santa Barbara, CA 93101, USA
    2. Department of Biological Sciences, University of Toronto – Scarborough, 1265 Military Trail, Scarborough, ON M1C 1A4, Canada
      * E-mail:mcadotte@utsc.utoronto.ca
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  • T. Jonathan Davies,

    1. National Center for Ecological Analysis and Synthesis, University of California, 735 State St., Santa Barbara, CA 93101, USA
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  • James Regetz,

    1. National Center for Ecological Analysis and Synthesis, University of California, 735 State St., Santa Barbara, CA 93101, USA
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  • Steven W. Kembel,

    1. Integrative Biology, University of California, Berkeley, CA 94720, USA
    2. Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, OR 97403, USA
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  • Elsa Cleland,

    1. National Center for Ecological Analysis and Synthesis, University of California, 735 State St., Santa Barbara, CA 93101, USA
    2. Ecology, Behavior and Evolution, University of California – San Diego, La Jolla, CA 92093, USA
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  • Todd H. Oakley

    1. Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93107, USA
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* E-mail:mcadotte@utsc.utoronto.ca

Abstract

Phylogenetic information is increasingly being used to understand the assembly of biological communities and ecological processes. However, commonly used metrics of phylogenetic diversity (PD) do not incorporate information on the relative abundances of individuals within a community. In this study, we develop three indices of PD that explicitly consider species abundances. First, we present a metric of phylogenetic-abundance evenness that evaluates the relationship between the abundance and the distribution of terminal branch lengths. Second, we calculate an index of hierarchical imbalance of abundances at the clade level encapsulating the distribution of individuals across the nodes in the phylogeny. Third, we develop an index of abundance-weighted evolutionary distinctiveness and generate an entropic index of phylogenetic diversity that captures both information on evolutionary distances and phylogenetic tree topology, and also serves as a basis to evaluate species conservation value. These metrics offer measures of phylogenetic diversity incorporating different community attributes. We compare these new metrics to existing ones, and use them to explore diversity patterns in a typical California annual grassland plant community at the Jasper Ridge biological preserve.

Ecology Letters (2010) 13: 96–105

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