Beta diversity

Beta diversity

Beta diversity (β-diversity) is a measure of biodiversity which works by comparing the species diversity between ecosystems or along environmental gradients. This involves comparing the number of taxa that are unique to each of the ecosystems.

It is the rate of change in species composition across habitats or among communities. It gives a quantitative measure of diversity of communities that experience changing environments.See alpha diversity, gamma diversity, global diversity.

Indices

* Sørensen's similarity indexSørensen, T.A. (1948) A method of establishing groups of equal amplitude in plant sociology based on similarity of species content, and its application to analyses of the vegetation on Danish commons. Kongelige Danske Videnskabernes Selskabs Biologiske Skrifter, 5, 1–34.] eta=frac{2c}{S_1+S_2}

where, S1= the total number of species recorded in the first community, S2= the total number of species recorded in the second community, and c= the number of species common to both communities. The Sørensen index is a very simple measure of beta diversity, ranging from a value of 0 where there is no species overlap between the communities, to a value of 1 when exactly the same species are found in both communities.

* Whittaker's measure [Whittaker, R.H. (1960) Vegetation of the Siskiyou mountains, Oregon and California. Ecological Monographs, 30, 279–338.] eta=frac{S}{ar alpha} or eta=frac{S}{ar alpha}-1

where, S= the total number of species recorded in both communities, ar alpha=average number of species found within the communities.

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • beta diversity — /ˈbitə dəvɜsəti/ (say beetuh duhversuhtee) noun a measure of the differences in biodiversity which are found when comparing the biodiversity of one particular area or ecosystem with another; can be expressed by the number of species found in one… …  

  • Beta-Diversität — ist ein Maß für die ökologische Vielfalt (engl: diversity, eingedeutscht zu Diversität) auf einer mittleren Raumebene, der sog. Landschaftsebene. Der Ausdruck wird definiert in einer Theorie des amerikanischen Ökologen Robert H. Whittaker… …   Deutsch Wikipedia

  • Beta-lactamase — Beta lactamases are enzymes (EC number|3.5.2.6) produced by some bacteria and are responsible for their resistance to beta lactam antibiotics like penicillins, cephalosporins, cephamycins, ertapenems and carbapenems. These antibiotics have a… …   Wikipedia

  • Beta Colony — is an important planet (although rarely the setting) in Lois McMaster Bujold s science fiction series the Vorkosigan Saga. The planet s biome is almost entirely desert, described as screaming hot, and the colony itself exists primarily… …   Wikipedia

  • Beta Kappa Gamma — Infobox Fraternity letters=ΒKΓ name=Beta Kappa Gamma colors=Blue, Yellow, and Black motto= Brotherhood + Knowledge = Growth ΟΜΙIA KAI MΘHΣIΣ ΨYXAΣ TPEΦOYI symbol=Phoenix crest= founded=birth date and age|1999|5|6 birthplace=University of Texas at …   Wikipedia

  • Beta-peptide — β peptides consist of β amino acids, which have their amino group bonded to the β carbon rather than the α carbon as in the 20 standard biological amino acids. The only commonly naturally occurring β amino acid is β alanine; although it is used… …   Wikipedia

  • Diversity of fish — Fish come in many shapes and sizes. This is a sea dragon, a close relative of the seahorse. They are camouflaged to look like floating seaweed.[1][2][3] …   Wikipedia

  • Gamma diversity — (γ diversity) is a measure of biodiversity. It refers to the total biodiversity over a large area or region. It is the total of α and β diversity.According to Whittaker (1972), gamma diversity is the richness in species of a range of habitats in… …   Wikipedia

  • Alpha diversity — (α diversity) is the biodiversity within a particular area, community or ecosystem, and is usually expressed as the species richness of the area.[1] This can be measured by counting the number of taxa (distinct groups of organisms) within the… …   Wikipedia

  • gamma diversity — /ˈgæmə dəvɜsəti/ (say gamuh duhversuhtee) noun the overall biodiversity exhibited in a large region with several different ecosystems; can be expressed by giving the number of species not found in all the component ecosystems, stating in which… …  

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”