Biodiversity is the variation of life forms within a given ecosystem, biome, or on the entire Earth. Biodiversity is often used as a measure of the health of biological systems. The biodiversity found on Earth today consists of many millions of distinct biological species. The year 2010 has been declared as the International Year of Biodiversity.
Biodiversity is not distributed evenly on Earth, but is consistently rich in the tropics and in specific localized regions such as the Cape Floristic Province; it is less rich in polar regions where fewer species are found.
Rapid environmental modifications typically cause extinctions. Of all species that have existed on Earth, 99.9 percent are now extinct. Since life began on Earth, five major mass extinctions have led to large and sudden drops in the biodiversity of species. The Phanerozoic eon (the last 540 million years) marked a rapid growth in biodiversity in the Cambrian explosion—a period during which nearly every phylum of multicellular organisms first appeared. The next 400 million years was distinguished by periodic, massive losses of biodiversity classified as mass extinction events. The most recent, the Cretaceous–Tertiary extinction event, occurred 65 million years ago, and has attracted more attention than all others because it killed the dinosaurs..
As it holds the key to progress in medicine, agriculture, forestry and other fields. Botanist Alvin Gentry estimates that 15,000-20,000 species of tropical flowering plants are yet to be documented.
India is one of the world's 12 mega-biodiversity centres, and the subcontinent one of the six Vavilovian centres of origin of species. Some 45,000 plant species and over 89,000 species of animals have been documented here, comprising some 6.5 per cent of all known wildlife. The faunal diversity comprises inter alia 2,500 fishes, 150 amphibians, 450 reptiles, 1,200 birds, 850 mammals and 68,000 insects. Although India is designated as a mega-biodiversity area, it also has two of the world's most threatened 'hot spots', the Eastern Himalayan region and the Western Ghats. To quote Professor M.S. Swaminathan, both are paradises of valuable genes but are inching towards the status of 'Paradise Lost.
India has a rich and varied heritage of biodiversity, encompassing a wide spectrum of habitats from tropical rainforests to alpine vegetation and from temperate forests to coastal wetlands. India figured with two hotspots - the Western Ghats and the Eastern Himalayas.
India contributes significantly to latitudinal biodiversity trend. With a mere 2.4% of the world's area, India accounts for 7.31% of the global faunal total with a faunal species count of 89,451 species.
India has two major realms called the Palaearctic and the Indo-Malayan, and three biomass, namely the tropical humid forests, the tropical dry/deciduous forests, and the warm desert/semi-deserts. India has ten biogeographic regions including the Trans-Himalayan, the Himalayan, the Indian desert, the semi-arid zone(s), the Western Ghats, the Deccan Peninsula, the Gangetic Plain, North-East India, and the islands and coasts.
India is one of the 12 centres of origin of cultivated plants. India has 5 world heritage sites, 12 biosphere reserves, and 6 Ramsar wetlands. Amongst the protected areas, India has 88 national parks and 490 sanctuaries covering an area of 1.53 lakh sq. km.
India's record in agro-biodiversity is equally impressive. There are 167 crop species and wild relatives. India is considered to be the centre of origin of 30,000-50,000 varieties of rice, pigeon-pea, mango, turmeric, ginger, sugarcane, gooseberries etc and ranks seventh in terms of contribution to world agriculture.
The Conference of the Parties (COP) established under the CBD at its sixth session in 2002 set common global targets to reduce the loss of biodiversity by 2010. These include:
• Conservation of biodiversity at the level of ecosystems, species and genes;
• Addressing risks such as invasive alien species, global warming and developments that threaten the natural environment;
• Maintaining the function of ecological services that support human livelihood;
• Maintaining the rights of the aboriginal people and protecting their traditional knowledge;
• Ensuring equal and equitable distribution of profits from the use of genetic resources.