You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
A Consumer's Guide to Evenness Indices
Benjamin Smith and J. Bastow Wilson
Vol. 76, No. 1 (May, 1996), pp. 70-82
Stable URL: http://www.jstor.org/stable/3545749
Page Count: 13
You can always find the topics here!Topics: Diversity indices, Species, Ecological sustainability, Zero, Species diversity, Discourse communities, Synecology, Desire, Blisters, Radiocarbon
Were these topics helpful?See somethings inaccurate? Let us know!
Select the topics that are inaccurate.
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Many indices have been proposed for measuring species evenness in ecological communities, but there is no consensus on which are best. We assemble criteria for an appropriate index for the evenness of a biological sample. The most important criterion is that evenness should be independent of species richness. Twelve previously proposed indices and variants are considered, and two apparently new indices. Four indices are recommended as joint best buys: A) If symmetry between minor and abundant species is not important, or if it is required that the index be less affected by minor species: 1) If it is essential that the index be able to reach a minimum of zero with any particular number of species, or if the shape of the index response to an evenness gradient is important: E1/D (based on a common form of Simpson's index). 2) If good mid-range behaviour is desired: E′ (proposed by Camargo). B) If equal sensitivity to minor and abundant species is required: 1) If the shape of the index response to an evenness gradient is not important, the clear winner is: EQ (a new index). 2) If the shape is important: Evar (another new index). The overall recommendation for general use is Evar.
Oikos © 1996 Nordic Society Oikos