Breaking News
Home » Environmental science » Biodiversity » Biodiversity and its types – complete detail – updated

Biodiversity and its types – complete detail – updated

Biodiversity and its types – complete detail – updated. What is Biodiversity. Definition of Biodiversity. Introduction of Biodiversity. Biodiversity is the variety of all species on our planet. It includes different plants, animals, birds, and micro-organisms, their genes, their habitats and all the ecosystems (forests, grass-lands, lacks, ponds, rivers, wet-lands etc.).  
“Biological diversity” means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part: this………..

Introduction

Biodiversity is also known as biological diversity. Biodiversity is the variety of all species on our planet. It includes different plants, animals, birds and micro-organisms, their genes, their habitats and all the ecosystems (forests, grass-lands, lacks, ponds, rivers, wet-lands etc.).

The term “biological diversity” was first used in year 1980 by Lovejoy (most commonly used to describe the number of species).

 “Biological diversity” means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems.

Biodiversity or biological diversity includes variety within and among organisms of the ecological systems they comprise.

Biodiversity can be classified under three levels;

  1. Ecosystem or ecological diversity
  2. Species diversity
  3. Genetic diversity

E. O. Wilson first used the term “biodiversity” in 1988. Biodiversity encompasses the variety of life, at all levels. Biodiversity is an attribute of an area and specifically refers to the variety within and among living organisms, biotic communities, and biotic processes, whether naturally occurring or modified by humans. Biodiversity is the variety of life on earth and includes variation at all levels of biological organization from genes to species to ecosystems. Genetic, organism and ecological diversity are all elements of biodiversity with each including a number of components.

  1. Ecosystem or ecological diversity

There is 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 forest, grasslands, deserts, mountains as well as 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. Ecosystem diversity is often evaluated through measures of the diversity of the component species. This may involve assessment of the relative abundance of different species as well as consideration of the types of species. Weight is given to the numbers of species in different size classes, at different trophic levels, or in different taxonomic groups. Thus a hypothetical ecosystem consisting only of several plant species would be less diverse than one with the same number of species but that included animal herbivores and predators.

Ecosystem diversity has three perspectives;

  1. Alpha (α) Diversity  

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

  1. Beta (β) Diversity

Beta 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.

  1. Gamma (γ) Diversity

It refers to the total species richness over a large area. It is a measure of the overall diversity for the different ecosystems within a region. It is a product of alpha diversity of component ecosystems and the beta diversity between component ecosystems. Gamma diversity can be expressed in terms of the species richness of component communities as follows;

γ = s1 + s2 – c

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                                                    

  1. 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 number of species of plants and animals that are present in a region constitutes its species diversity. This diversity is seen both in natural ecosystem and in agricultural ecosystems. Some areas are richer in species than others.

  1. Genetic diversity

Genetic diversity is reliant on the heritable variation within and between populations of organisms. New genetic variation arises in individuals by gene and chromosome mutations, and in organisms with sexual reproduction it can be spread through the population by recombination. It has been estimated that in humans and fruit flies alike, the number of possible combinations of different forms of each gene sequence exceeds the number of atoms in the universe. Other kinds of genetic diversity can be identified at all levels of organization, including the amount of DNA per cell and chromosome structure and number. Selection acts on this pool of genetic variation present within an interbreeding population. Differential survival results in changes of the frequency of genes within this pool, and this are equivalent to population evolution. Genetic variation enables both natural evolutionary change and artificial selective breeding to occur. Only a small fraction of the genetic material of higher organisms is outwardly expressed in the form and function of the organism; the purpose of the remaining DNA and the significance of any variation within it are unclear. Each of the estimated 109 different genes distributed across the world’s biota does not make an identical contribution to overall genetic diversity.

About Vijay Choudhary

One comment

  1. Dear, smog is a growing problem in front of us. we can take few steps to minimize this like…
    * Awareness programmes for all peoples (about smog, causes, impacts and how to control)
    * Encourage peoples for plantation, and organize plantation programmes
    * Educate to local peoples about the importance of nature and natural resources
    * Educate peoples about Sustainable Development

Leave a Reply

Your email address will not be published.