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When all types in the dataset of interest are equally common, all p i values equal 1 / R, and the Shannon index hence takes the value ln(R). The more unequal the abundances of the types, the larger the weighted geometric mean of the p i values, and the smaller the corresponding Shannon entropy. If practically all abundance is concentrated to ...
The Shannon index is the most commonly used way to quantitatively determine species diversity, H, as modeled by the following equation: = = The Shannon index factors in both species evenness and species richness, as represented by the variables p i and s, respectively. The lowest possible value of H is zero, and the higher a community’s H ...
There are many ways to measure biodiversity within a given ecosystem. However, the two most popular are Shannon-Weaver diversity index, [4] commonly referred to as Shannon diversity index, and the other is Simpsons diversity index. [5] Although many scientists prefer to use Shannon's diversity index simply because it takes into account species ...
Pielou's evenness [3] is an index that measures diversity along with species richness. While species richness is the number of different species in a given area, evenness is the count of individuals of each species in an area. A calculated value of Pielou's evenness ranges from 0 (no evenness) to 1 (complete evenness).
In ecology, beta diversity (β-diversity or true beta diversity) is the ratio between regional and local species diversity.The term was introduced by R. H. Whittaker [1] together with the terms alpha diversity (α-diversity) and gamma diversity (γ-diversity).
A rank abundance curve or Whittaker plot is a chart used by ecologists to display relative species abundance, a component of biodiversity. It can also be used to visualize species richness and species evenness. It overcomes the shortcomings of biodiversity indices that cannot display the relative role different variables played in their ...
The source for this is a 1989 work by Charles J. Krebs. In a newer work, however (CJ Krebs. Ecology: the experimental analysis of distribution and abundance, 5th edition. p617-618), the same author calls the index the Shannon-Wiener index. Is there other information that could be used to find the "correct" name for the index, if one exists?
The Wiener index is named after Harry Wiener, who introduced it in 1947; at the time, Wiener called it the "path number". [2] It is the oldest topological index related to molecular branching. [ 3 ] Based on its success, many other topological indexes of chemical graphs, based on information in the distance matrix of the graph, have been ...