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Shannon-Wiener index of diversity
Shannon-Wiener index of diversity(information index) A measure derived from information theories developed by Claude E. Shannon and Norbert Wiener and published in 1949 by Shannon and Warren Weaver, which is used by ecologists when a system contains too many individuals for each to be identified and examined. A small sample is used; the index (D) is the ratio of the number of species to their importance values (e.g. biomass or productivity) within a trophic level or community. D = − Σsipilogpi, where s is the total number of species in the sample, i is the total number of individuals in one species, pi (a decimal fraction) is the number of individuals of one species in relation to the number of individuals in the population, and the log is to base-2 or base-e.
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MICHAEL ALLABY. "Shannon-Wiener index of diversity." A Dictionary of Ecology. 2004. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Shannon-Wiener index of diversity." A Dictionary of Ecology. 2004. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O14-ShannonWienerindexfdvrsty.html MICHAEL ALLABY. "Shannon-Wiener index of diversity." A Dictionary of Ecology. 2004. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-ShannonWienerindexfdvrsty.html |
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Shannon–Wiener index of diversity
Shannon–Wiener index of diversity (information index) A measure used by ecologists when a system contains too many individuals for each to be identified and examined. A small sample is used; the index (D) is the ratio of the number of species to their importance values (e.g. biomass or productivity) within a trophic level or community. D = −Σsipi log pi, where s is the total number of species in the sample, i is the total number of individuals in one species, pi, (a decimal fraction) is the number of individuals of one species in relation to the number of individuals in the population, and the log is to base-2 or base-e.
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Cite this article
MICHAEL ALLABY. "Shannon–Wiener index of diversity." A Dictionary of Zoology. 1999. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Shannon–Wiener index of diversity." A Dictionary of Zoology. 1999. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O8-ShannonWienerindexfdvrsty.html MICHAEL ALLABY. "Shannon–Wiener index of diversity." A Dictionary of Zoology. 1999. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-ShannonWienerindexfdvrsty.html |
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Shannon-Wiener index of diversity
Shannon-Wiener index of diversity (Shannon-Weaver index, information index) A measure, derived from information theories developed by Claude E. Shannon and Norbert Wiener and published in 1949 by Shannon and Warren Weaver, that is used by ecologists when a system contains too many individuals for each to be identified and examined. A small sample is used; the index is the ratio of the number of species to their importance values (e.g. biomass or productivity) within a trophic level or community.
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Cite this article
MICHAEL ALLABY. "Shannon-Wiener index of diversity." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "Shannon-Wiener index of diversity." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O7-ShannonWienerindexfdvrsty.html MICHAEL ALLABY. "Shannon-Wiener index of diversity." A Dictionary of Plant Sciences. 1998. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-ShannonWienerindexfdvrsty.html |
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