Biodiversity

· Biodiversity occurs not only in the species level, but also in the macromolecular levels.

· Biodiversity as described by Edward Wilson is the combined diversity at all levels of biological organisation.

The most important forms of biodiversity are:

o Genetic diversity

o Species diversity

o Ecological diversity

Genetic diversity

Ø A single species might show high diversity at the genetic level over its distributional range.

Ø The genetic variation shown by the medicinal plant Rauwolfia vomitoria growing in different Himalayan ranges might be in terms of the potency and concentration of the active chemical (reserpine) that the plant produces.

Ø India has more than 50,000 genetically different strains of rice, and 1,000 varieties of mango.

Species diversity

Ø The diversity at the species level.

Ø For example, the Western Ghats have a greater amphibian species diversity than the Eastern Ghats.

Ecological diversity

Ø At the ecosystem level, India, for instance, with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows has a greater ecosystem diversity than a Scandinavian country like Norway.

· There are close to 1.5 million plants and animals that have to be discovered and described. More species have been discovered in temperate regions as compared to tropics.

· According to an estimate made by Robert May, global species biodiversity is about 7 million.

· Of the total species discovered so far, 70% are animals and 22% are plants. Of the animals, 70% are insects.

· India has 2.4% of the world’s land and 8.1% of the total species diversity. According to May’s estimate, 78% of the biodiversity is still to be discovered.

· Applying this to India’s biodiversity figures, there still is a scope for discovery of over 1 lakh species of plants and 3 lakh species of animals.