Interpreting and estimating measures of community phylogenetic structuring
Article first published online: 12 AUG 2008
© 2008 The Authors. Journal compilation © 2008 British Ecological Society
Journal of Ecology
Volume 96, Issue 5, pages 849–852, September 2008
How to Cite
Hardy, O. J. and Jost, L. (2008), Interpreting and estimating measures of community phylogenetic structuring. Journal of Ecology, 96: 849–852. doi: 10.1111/j.1365-2745.2008.01423.x
- Issue published online: 12 AUG 2008
- Article first published online: 12 AUG 2008
- Received 27 February 2008; accepted 18 June 2008Handling Editor: David Burslem
- community ecology;
- community structure;
- diversity partitioning;
- parameter estimation;
- phylogenetic diversity;
- quadratic entropy;
- Simpson's diversity
- 1To characterize the spatial phylogenetic structure of communities, Hardy & Senterre (2007) (J. Ecol., 95, 493–506) partition Gini–Simpson diversity and its generalization, Rao's entropy, defining IST and PST as the proportion of diversity expressed among sites.
- 2Interpreting IST as a measure of ‘differentiation’ between sites is inadequate because low values are actually compatible with high differentiation (low species sharing) in species rich communities. To avoid an inadequate use of IST, for example in conservation biology, we offer a more literal interpretation: IST expresses the ‘local species identity excess’. Similarly, PST expresses the ‘local phylogenetic similarity excess’.
- 3Villéger & Mouillot (2008) (J. Ecol., 96, 845–848, this issue) argue that the equations of Hardy & Senterre (2007) to compute diversity are inadequate when sites differ in size, and they provide new expressions weighting sites by their sizes. We argue that whether sites must be weighted equally or not depends on the question being asked. Moreover, actual size and sample size must be distinguished, the latter being important for defining estimators.