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B.

90

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C.

90

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(a) IUCN Red List. It is a catalogue of taxa that are facing the risk of extinction. The uses of red list are (i) developing awareness, about the threat of loss of biodiversity (ii) identification and documentation of endangered species (iii) providing a global index of the decline of biodiversity (iv) defining conservation.

IUCN has recognized eight red list categories of species. They are :

(i) Extinct (ii) Extinct in wild (iii) Critically endangered (iv) Endangered (v) Vulnerable (vi) Lower risk (vii) Data deficient and (viii) Not evaluated.

The 2000 red list contains assessment of more than 18,000 species, 11,000 of which are threatened.

(b) Protected areas. These areas are areas of land or sea that are dedicated to the protection and maintenance of biological diversity. They include National Parks, Sanctuaries and Biosphere reserve. India has 14 biosphere reserves, 90 national parks and 448 wildlife sanctuaries

 

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â–² Fie. 7.2. Representation of global biodiversity of major taxa of plants, invertebrates and vertebrates

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Threats to biodiversity which may lead to 

1. Habitat loss- The destruction of habitat due to natural calamity or human activity may lead to extinction of many species and loss of biodiversity.

2. Disturbance and pollution. Large number of organisms are killed due to natural disturbances such as fire, tree fall, defoliation by insects. Human activities also lead to loss of biodiversity.

3. Introduction of exotic species. Introduction of new species into an area cause disturbances which may lead to disappearance of native species.

4. Co-extinction is when extinction of one species leads to the extinction of some other mutually dependent species.