title: Deconstructing the relationships between phylogenetic diversity and ecology: a case study on ecosystem functioning.
abstract: Recent studies have supported a link between phylogenetic diversity and various ecological properties including ecosystem function. However, such studies typically assume that phylogenetic branches of equivalent length are more or less interchangeable. Here we suggest that there is a need to consider not only branch lengths but also their placement on the phylogeny. We demonstrate how two common indices of network centrality can be used to describe the evolutionary distinctiveness of network elements (nodes and branches) on a phylogeny. If phylogenetic diversity enhances ecosystem function via complementarity and the representation of functional diversity, we would predict a correlation between evolutionary distinctiveness of network elements and their contribution to ecosystem process. In contrast, if one or a few evolutionary innovations play key roles in ecosystem function, the relationship between evolutionary distinctiveness and functional contribution may be weak or absent. We illustrate how network elements associated with high functional contribution can be identified from regressions between phylogenetic diversity and productivity using a well-known empirical data set on plant productivity from the Cedar Creek Long-Term Ecological Research. We find no association between evolutionary distinctiveness and ecosystem functioning, but we are able to identify phylogenetic elements associated with species of known high functional contribution within the Fabaceae. Our perspective provides a useful guide in the search for ecological traits linking diversity and ecosystem function, and suggests a more nuanced consideration of phylogenetic diversity is required in the conservation and biodiversity-ecosystem-function literature.
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, H3G 0B1, Canada.|African Centre for DNA Barcoding, University of Johannesburg, PO Box 524, Auckland Park, 2006, Johannesburg, South Africa.
authors.forename: T Jonathan
authors.initials: TJ
authors.lastname: Davies
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, 06269-3043, USA.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Urban
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, H3G 0B1, Canada.|Département des sciences naturelles, Institut des sciences de la forêt tempérée, Université du Québec en Outaouais, 58 rue Principale, Ripon, Quebec, J0V 1V0, Canada.
authors.forename: Bronwyn
authors.initials: B
authors.lastname: Rayfield
authors.affiliation: Biological Sciences, University of Toronto-Scarborough, Toronto, Ontario, M1C 1A4, Canada.
authors.forename: Marc W
authors.initials: MW
authors.lastname: Cadotte
authors.affiliation: Canada Research Chair in Spatial Modelling and Biodiversity, Département des sciences biologiques, Université du Québec á Montréal, Montréal, Quebec, H2X 1Y4, Canada.
authors.forename: Pedro R
authors.initials: PR
authors.lastname: Peres-Neto
mesh_terms: D044822:Biodiversity; D005075:Biological Evolution; D004463:Ecology; D017753:Ecosystem; D010802:Phylogeny
keywords: complementarity; ecosystem function; key innovations; phylogenetic diversity; productivity; sampling effect