Measurement of biodiversity

Source: Wikipedia, the free encyclopedia.

A variety of objective means exist to empirically measure biodiversity. Each measure relates to a particular use of the data, and is likely to be associated with the variety of genes.

Simpsons diversity index.[5] Although many scientists prefer to use Shannon's diversity index simply because it takes into account species richness.[6]

Biodiversity is usually plotted as the richness of a geographic area, with some reference to a temporal scale. Types of biodiversity include

ecological, morphological, and genetic diversity. Taxonomic diversity, that is the number of species, genera, family is the most commonly assessed type.[7] A few studies have attempted to quantitatively clarify the relationship between different types of diversity. For example, the biologist Sarda Sahney has found a close link between vertebrate taxonomic and ecological diversity.[8]

Conservation biologists have also designed a variety of objective means to empirically measure biodiversity. Each measure of biodiversity relates to a particular use of the data. For practical conservationists, measurements should include a quantification of values that are commonly shared among locally affected organisms, including humans[clarification needed]. For others, a more economically defensible definition should allow the ensuring of continued possibilities for both adaptation and future use by humans, assuring environmental sustainability.

As a consequence, biologists argue that this measure is likely to be associated with the variety of genes. Since it cannot always be said which genes are more likely to prove beneficial, the best choice[

conservation is to assure the persistence of as many genes as possible. For ecologists, this latter approach is sometimes considered too restrictive, as it prohibits ecological succession
.

Taxonomic diversity

Biodiversity is usually plotted as taxonomic richness of a geographic area, with some reference to a temporal scale. Whittaker[9] described three common metrics used to measure species-level biodiversity, encompassing attention to species richness or species evenness:

  • Species richness - the simplest of the indices available.
  • Simpson index
  • Shannon-Wiener index

More recently, two new indices have been invented. The

land use change
and intensification.

Other measures of diversity

Alternatively, other types of diversity may be plotted against a temporal timescale:

These different types of diversity may not be independent. There is, for example, a close link between vertebrate taxonomic and ecological diversity.[11]

Other authors tried to organize the measurements of biodiversity in the following way:[12]

  • traditional diversity measures
    • species density, take into account the number of species in an area
    • species richness, take into account the number of species per individuals (usually [species]/[individuals x area])
    • diversity indices, take into account the number of species (the richness) and their relative contribution (the evenness); e.g.:
      • Simpson index
      • Shannon-Wiener index
  • phylogenetic diversity measures, include information on phylogenetic relationships among species
    • phylogenetic diversity (PD) index; Faith (1992)
    • topology based measures
      • taxonomic distinctiveness; Vane-Wright et al. (1991)
      • taxonomic diversity; Warwick & Clarke (1995)
      • taxonomic distinctness; Clarke & Warwick (1998)
  • functional diversity
    measures, include information on functional traits among species
    • categoric measures
      • functional group richness (FGR); e.g., Tilman et al. (1997)
    • continuous measures
      • with only one functional trait; e.g., Mason et al. (2003)
      • multivariate measures, with many functional traits
        • functional attribute diversity (FAD); Walker et al. (1999)
        • convex hull volume; Cornwell et al. (2006)
        • functional diversity (FD); Petchey & Gaston (2002)

Scale

Diversity may be measured at different scales. These are three indices used by ecologists:

  • Alpha diversity refers to diversity within a particular area, community or ecosystem, and is measured by counting the number of taxa within the ecosystem (usually species)[13]
  • unique to each of the ecosystems
    .
  • Gamma diversity is a measurement of the overall diversity for different ecosystems within a region.

See also

References

  1. ^ "Species Evenness - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2023-02-25.
  2. S2CID 244883885
    , retrieved 2023-02-25
  3. PMID 15748806
    .
  4. ISBN 978-94-017-8801-4
    , retrieved 2023-02-25
  5. ISBN 978-0-19-956766-9
    , retrieved 2023-02-25
  6. PMID 25478144
    .
  7. PMID 18198148
    .
  8. PMID 20106856
    .
  9. ^ Whittaker, R.H., Evolution and measurement of species diversity, Taxon, 21, 213–251 (1972)
  10. ^ "MSA Index (page 4)" (PDF). Archived from the original (PDF) on 2008-05-10. Retrieved 2008-05-10.
  11. PMID 20106856.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  12. ^ Cianciaruso, M.V., Silva, I.A. & Batalha, M.A. Diversidades filogenética e funcional: novas abordagens para a Ecologia de comunidades. Biota Neotrop. 9(3): [1].
  13. PMID 18198148
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Measurement_of_biodiversity&oldid=1211169090"