Ecology and Environment Notes Part 4 – Causes of Loss of Biodiversity

Causes of Loss of Biodiversity

The accelerated rate of species extinction is largely due to human activities. There are 4-major causes, called

‘The Evil Quartet’, for the loss of biodiversity –

  • Habitat loss and fragmentation
  • Overexploitation
  • Invasion of Alien or exotic species
  • Co-extinctions

The Conservation of biodiversity can be in situ (on site) or ex-situ (off-site)–

In such conservation, the endangered species are protected in their natural habitat with an entire ecosystem. The conservationists, on a global basis, have identified certain Biodiversity Hot Spots

The 3-biodiversity hotspots of India, that cover rich-biodiversity regions, are

  • Western Ghats
  • Himalaya
  • Indo-Burma

The in-situ conservation in India is done through 15– Biosphere reserves, 90-National Parks, more than 450 sanctuaries and several Sacred Groves or the tracts of forests.

Biosphere reserves

They represent natural biomes which contain unique biological communities. They include land as well as the coastal environment. (i)Core (natural) zone – It is innermost zone

(ii) Buffer zone – In this zone, limited human activity is allowed for research and education purposes

(iii) Transition (manipulation) zone – It is the outermost zone of a biosphere reserve in which a large number of human activities are permitted,

National Parks

They are reserved for the betterment of wildlife, both fauna and flora. In national parks, private ownership is not allowed. The grazing, cultivation, forestry etc. is also not permitted. The first national park of the world, Yellow stone, in the U.S.A., was founded in 1872.


In sanctuaries, the protection is given to fauna only. The activity like the harvesting of timber, a collection of forest products and private ownership rights are permitted so long as they do not interfere with the well-being of the animals. The important wildlife sanctuaries are Chilka wildlife sanctuary (Odisha), Bharatpur Bird Sanctuary (Rajasthan),

The sacred groves are found in Khasi and Jaintia hills (Meghalaya), Aravalli hills (Rajasthan), Western Ghats (Karnataka and Maharashtra) and Sarguja, Chanda and Bastar areas of Madhya Pradesh.

Ex situ conservation in such type of conservation the threatened animals and plants are taken out of their natural habitat and are protected in special parks or areas like Zoological parks, Wildlife safari parks and Botanical gardens etc. The ex situ conservation also includes Cryopreservation.

Leave a Comment

Your email address will not be published.