Biodiversity and Conservation Notes P - 1 {NEET}

Biodiversity and Conservation

Definition

Biodiversity (Gk, bios-life; diversity-forms) or Biological diversity can be defined as the vast array of species of living organism present on  the earth.

The term, ‘Biodiversity, was coined by WG Rosen (1985), but later Popularised by EO Wilson.

Due to difference in habitat and environment the `biodiversity can studied at global as well as country level.

 In India `maximum species of Arthropods are found (approx  68389) among animals while among plants maximum species 'of angiosperms are found (17500).

Levels of Biodiversity

For the convenience of study, the biodiversity can be categorized in the following three levels of biological organisations

(i) Genetic Diversity (within species diversity)

The diversity in number and types of genes as well as chromosomes present in different species and the variation in the genes and their alleles in same species.

It is useful as it involves the adaptation to change in the environmental conditions and is also essential for healthy breeding.

 It also helps in speciation.

[ii] Species diversity (between species diversity)

It means the species richness in any habitat. Greater the species richness, greater  will be their diversity.

India is among the world’s 15 nation that are exceptionally rich in species diversity.

 Number of individuals of different species represents the species evenness and species equitability.

[iii] Community & Ecosystem Diversity (ecologicai diversity)

 It is the diversity at ecosystem or community level. An ecosystem is Referred to as natural when it is undisturbed by human activities.

Diversity at the  level of community or ecosystem has three

Perspective, i.e., α, β and ϒ (Whittaker1965).

BIOGEOGRAPHIC CLASSIFICATION OF INDIA

Our country can be conveniently divided into ten major regions, based on the geography, climate and pattern of vegetation seen and the communities of mammals, birds, reptiles, amphibia, insects and other invertebrates that live in them.

Each of these regions contains a variety of ecosystems such as forests, grasslands, lakes, rivers, wetlands, mountains and hills, which have specific plant and animal species.

 India’s Biogeographic Zones

1. The cold mountainous snow covered Trans Himalayan region of Ladakh.
2. The Himalayan ranges and valleys of Kashmir, Himachal Pradesh, Uttarakhand, Assam and other North Eastern States.
3. The Terai, the lowland where the Himalayan rivers flow into the plain
4. The Gangetic and Bhramaputra plains.
5. The Thar Desert of Rajasthan.
6. The semi arid grassland region of the Deccan plateau Gujarat, Maharashtra, Andra Pradesh, Karnataka and Tamil Nadu.
7. The Northeast States of India,
8. The Western Ghats in Maharashtra, Karnataka and Kerala.
9. The Andaman and Nicobar Islands.
10. The long western and eastern coastal belt with sandy beaches, forests and mangroves