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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 ...
The observed species richness is affected not only by the number of individuals but also by the heterogeneity of the sample. If individuals are drawn from different environmental conditions (or different habitats), the species richness of the resulting set can be expected to be higher than if all individuals are drawn from similar environments.
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.
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]
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. [1] [4] Usually relative species abundances are described for a single trophic level.
Species diversity is the number of different species that are represented in a given community (a dataset). The effective number of species refers to the number of equally abundant species needed to obtain the same mean proportional species abundance as that observed in the dataset of interest (where all species may not be equally abundant).
Consequently, some macroecological and community patterns cannot be fully expressed by alpha and beta diversity. Due to these two reasons, a new way of measuring species turnover, coined Zeta diversity (ζ-diversity), [ 12 ] has been proposed and used to connect all existing incidence-based biodiversity patterns.
Two global information systems are either dedicated to, or have strong focus on, biogeography (in the form of the spatial location of observations of organisms), namely the Global Biodiversity Information Facility (GBIF: 2.57 billion species occurrence records reported as at August 2023) [29] and, for marine species only, the Ocean Biodiversity ...