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Species richness [2] is the number of species present in a given area. Species diversity [3] is the relationship between species evenness and species richness. 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 ...
Resampling methods can be used to bring samples of different sizes to a common footing. [2] Properties of the sample, especially the number of species only represented by one or a few individuals, can be used to help estimating the species richness in the population from which the sample was drawn. [3] [4] [5]
SAD is a measurement of how common, or rare species are within an ecosystem. [5] This allows researchers to assess how different species are distributed throughout an ecosystem. SAD is one of the most basic measurements in ecology and is used very often, therefore many different methods of measurement and analysis have developed.
(derived from data presented in Magurran (2004) [2] and collected by C.B. Williams (1964) [3]) Relative species abundance and species richness describe key elements of biodiversity . [ 1 ] Relative species abundance refers to how common or rare a species is relative to other species in a given location or community.
The technique of rarefaction was developed in 1968 by Howard Sanders in a biodiversity assay of marine benthic ecosystems, as he sought a model for diversity that would allow him to compare species richness data among sets with different sample sizes; he developed rarefaction curves as a method to compare the shape of a curve rather than absolute numbers of species.
Species richness, or biodiversity, increases from the poles to the tropics for a wide variety of terrestrial and marine organisms, often referred to as the latitudinal diversity gradient. [1] The latitudinal diversity gradient is one of the most widely recognized patterns in ecology. [1] It has been observed to varying degrees in Earth's past. [2]
Ecologists have proposed a wide range of factors determining the slope and elevation of the species–area relationship. [2] These factors include the relative balance between immigration and extinction, [ 3 ] rate and magnitude of disturbance on small vs. large areas, [ 3 ] predator-prey dynamics, [ 4 ] and clustering of individuals of the ...
EBVs would be used to inform biodiversity change indicators, such as the CBD Biodiversity Indicators for the Aichi Targets. [2] The concept is partly based on the earlier Essential Climate Variables. [3] [4] It can be generalised as the minimum set of variables for describing and predicting a system's state and dynamics. Areas with more ...