Measuring biodiversity, Biology

Diversity is defined as the no of species present in a community termed as "species richness". We can represent species biodiversity at different geographical scales as alpha, beta and gamma diversity.

(a)         Alpha diversity: it indicates diversity within a particular area or ecosystem, and is usually  expressed by no of the species. Thus alpha diversity is measure of "species richness".

(b)         Beta diversity:  it refers  to the changes in species richness between ecosystem. The higher heterogeneity in the habitats in a region or greater dissimilarity between communities exhibit higher beta diversity.

Gamma diversity: it refers, to the diversity of the habitats over the total land scope or geographical area. The higher diversity at community levels provides stability and higher productivity. In temperate, grasslands, it has been observed that diverse communities are functionally more productive and stable, even under environment stresses such as prolonged dry conditions.

Extinction of species: A species is said to be extinct, when there is no reasonable doubt that its last individual has died.

The characteristic which make a species susceptible to extinction are listed below:

(i)                 Large body size eg. Elephant, lion and bengal.

(ii)               Small population size and low reproductive rate eg. Blue whale, giant panda.

(iii)             Feeding at high trophic levels in food chain eg. Bald eagle and bengal tiger.

(iv)              Fixed migratory routes and habitat eg. Blue whale and whooping crane.

(v)                Localized and narrow range distribution e.g. woodland caribou and island species.

Species become extinct by these three processes:

(i)                 Natural extinction

(ii)               Mass extinction

(iii)             Anthropogenic extinction

According to the world conservation monitoring centre (WCMC),533 animal (mostly vertebrates) and 384  plant species (mostly flowering plant) have become extinct since the year 1600.

Posted Date: 7/11/2012 7:39:58 AM | Location : United States







Related Discussions:- Measuring biodiversity, Assignment Help, Ask Question on Measuring biodiversity, Get Answer, Expert's Help, Measuring biodiversity Discussions

Write discussion on Measuring biodiversity
Your posts are moderated
Related Questions
Q. Explain microbiology of Soil? Ans. You would realize that the soil contains greatest varieties of microorganisms. It actually serves as a medium for growth and developm

However, according to conventional principles of economic analysis it is necessary that a resource is used for it to acquire a value. Consequently economists traditionally value bi

Anthrax Anthrax is primarily a disease of the herbivores and occurs in almost all parts of the world. The disease has declined recently throughout the world as a result of the

Why does bark often break and die naturally? Bark is the mature periderm of the branches, stem and roots. It breaks and dies when these structures grow and thus the peridermal

Q. Show the Communication process steps? Planning - Set goals. - Make a plan with alternatives. - Allow the counsellee to select a alternative which is feasible.

Q. What do you mean by Monographs? A monograph is defined as "the complete account as can be made at a given time of any one family, tribe or genus, nothing being neglected of

Acute Aortic Regurgitation :  The most dramatic presentation occurs in dissection of the aortic root. Endocarditis of the native or prosthetic aortic valve may also lead to a

Give an example of how two organisms are interdependent.

Vasa are a maternal-effect gene whose product functions in development of the posterior end of the Drosophila embryo.  runt is a non-maternal-effect gene whose product functions in