Biodiversity: Meaning and Types of Biodiversity

Biodiversity: Meaning and Types of Biodiversity

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Biodiversity: Meaning and Types of Biodiversity!


The great variety of life on earth has provided for man’s needs over thousands of years. This diversity of living creatures forms a support system which has been used by each civilization for its growth and development. Those that used this “bounty of nature” carefully and sustainably survived.


Those that overused or misused it disintegrated. Biodiversity is the part of nature which includes the difference in genes among the individuals of a species, the variety and richness of all the plant and animal species at different scales in space, locally in a region, in the country and the world and various types of ecosystems, both terrestrial and aquatic within a defined area. Biodiversity deals with the degree of nature’s variety in the biosphere.

‘Biological diversity’ or biodiversity is that part of nature which includes the differences in genes among the individuals of a species, the variety and richness of all the plant and animal species at different scales in space, locally, in a region, in the country and the world, and various types of ecosystems, both terrestrial and aquatic, within a defined area.

Biological diversity deals with the degree of nature’s variety in the biosphere. This variety can be observed at three levels; the genetic variability within a species, the variety of species within a community, and the organization of species in an area into distinctive plant and animal communities constitutes ecosystem diversity.

Biodiversity of Earth

Types of Biodiversity:


Genetic Diversity:

Each member of any animal or plant species differs widely from other individuals in its genetic makeup because of the large number of combinations possible in the genes that give every individual specific characteristic. Thus, for example, each human being is very different from all others.

This genetic variability is essential for a healthy breeding population of a species. If the number of breeding individuals is reduced, the dissimilarity of genetic makeup is reduced and in-breeding occurs. The diversity in wild species forms the ‘gene pool’ from which our crops and domestic animals have been developed over thousands of years.


Today the variety of nature’s bounty is being further harnessed by using wild relatives of crop plants to create new varieties of more productive crops and to breed better domestic animals. Modern biotechnology manipulates genes for developing better types of medicines and a variety of industrial products.

Species Diversity:

Species is a basic unit of classification and is defined as a group of similar organisms that mate and produce offspring’s with one another and thus, share a common lineage. The numbers of species of plants and animals that are present in a region constitutes its species diversity.

This diversity is seen both in natural ecosystems and in agricultural ecosystems. Some areas are richer in species than others. Natural undisturbed tropical forests have much greater species richness than plantations.

A natural forest ecosystem provides a large number of non-wood products that local people depend on such as fruit, fuel wood, fodder, fiber, gum, resin and medicines. At present conservation scientists have been able to identify and categorize about 1.75 million species on earth.


However, many new species are being identified, especially in the flowering plants and insects. Areas that are rich in species diversity are called ‘hotspots’ of diversity. India is among the world’s 15 nations that are exceptionally rich in species diversity.

Ecosystem or Community Diversity:

There are a large variety of different ecosystems on earth, which have their own complement of distinctive inter linked species based on the differences in the habitat. Ecosystem diversity can be described for a specific geographical region, or a political entity such as a country, a state or a taluka.

Distinctive ecosystems include landscapes such as forests, grasslands, deserts, mountains, etc., as well as aquatic ecosystems such as rivers, lakes, and the sea. Ecosystems are most natural in wilderness areas. If natural ecosystems are overused or misused their productivity eventually decreases and they are then said to be degraded. India is exceptionally rich in ecosystem diversity.

Community diversity has three perspectives:


1. Alpha Diversity:

It is the biodiversity within a particular area, community or ecosystem. It is usually expressed by the number of species (i.e., species richness) in that ecosystem. This can be measured by counting the number of taxa (distinct groups of organisms) within the ecosystem (e.g., families, genera, and species).

2. 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.


3. Gamma Diversity:

It refers to the total species richness over a large area or region. It is a measure of the overall diversity for the different ecosystems within a region. It is the product of a diversity of component ecosystems and the P diversity between component ecosystems.

Gamma diversity can be expressed in terms of the species richness of component communities as follows:

Y = S1 + S2 – c

Where, S1 = the total number of species recorded in the first community, S2 = the total number of species recorded in the second community, c = the number of species common to both communities.Types of Biodiversity & Three Perspectives of Community Biodiversity


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