Shannon-Wiener index of diversity

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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.

Shannon–Wiener index of diversity

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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.

Shannon-Wiener index of diversity

views updated

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.