Sanjeet Kumar
Ravenshaw University
Biological diversity is the variety and variability among living organisms and the ecological complexes in which they occur and encompasses species diversity, genetic diversity and ecosystem diversity. Scientifically 1.4 million species of living organisms have been enlisted so far. Of these, there are 360,000 microbes, 300,000 flowering plants, 800, 000 insects and 40, 000 vertebrates. However, it is believed that the actual number of species may be between 10-80 million. Rich and diverse forms of plant, animal and microbial life inhabits warm and humid regions in between the Tropic of Cancer and Capricon. Countries like Brazil, Columbia, Mexico, Peru, Ecuador, Indonesia, Malaysia, India, Zaire, Madagascar, Australia that are located in this region are known as mega diversity countries. Areas where high levels of species richness, threat and endemism coincide are termed hot-spots. In India we find high level of biodiversity, 48,000 plants reported so far represents 11 % of world flora while 80, 000 species of animals represents 6.4 % of world fauna. Biodiversity is important as it provides natural resources, genetic resources maintain stable ecosystem, ensure optimum utilization and conservation of a biotic resources. It is quite alarming that this enriched biodiversity on earth on which life is totally dependent is under threat of rapid loss. Various caused for the loss of biodiversity are the destruction of habitat, hunting, exploitation of selected species, habitat fragmentation, introduction of exotic species, pollution and natural calamities. To preserve these diverse biological species conservation measure have been undertaken. Either the biodiversity is conserved in its natural habitat (in situ conservation).
India is very rich in all aspects of biodiversity and is one of the most significant biodiversity centres of the world. Varying physiographic and climatic conditions at different parts of India are the reasons for this high level of biodiversity. India, with a geographical area of 329 million hectare has almost all kinds of ecological zones found in the world. India is the meeting ground for three major global bio- geographic regions.
1. Indo-Malayan
2. Eurasian
3. Afro-tropical
It has two of the 34 recognized biodiversity “Hotspots” in the world- The Himalaya and the Western Ghats.
48,000 species of plants which represents 11 % of the total world flora and 80,000 species of animals representing 6.4 % of the world’s fauna are found in India. India’s floral diversity includes 17,500 species of angiosperms, over 64 species of Gymnosperms, 1,022 species of Pteridophytes, 2,843 of Bryophytes, 1,600 species of lichens, 23,000 species of Fungi and 2,500 species of Algae. Similarly, the faunal diversity of India includes 5,000 species of molluscs, 60,000 species of mammals. According to an estimate 35 % of the flowering plants and 18 % of the total flora are endemic to India. The endemism among the animals is high and it may be as high as 62 % in case of Amphibians. Many of the biologically rich areas in India are either unexplored or underexplored. The present knowledge regarding the diversity of microorganisms, wetland flora and fauna and marine life is scanty. It will be quite relevant to mention here that the Indian sub-continent is one of the 12 centres of origin and diversity of crop plants. It has given to the world nearly 167 species of crop plants. The following crops arose in India and spread throughout the world: rice, sugarcane, jute, mango, citrus, banana, several millets, spices, medicinal, aromatics and ornamentals. The rich germplasm reserve of Indian sub-continent includes 51 species of cereals and millets, 104 species of fruits, 27 species of spices and condiments, 55 species of vegetables and pulses, 24 species of fibre crops, 12 species of oilseeds and various strains of wild tea, tobacco and sugarcane. Besides above , 1,000 species of plants are of ethnobotanical interest and 2,000 species are used in various traditional system of medicine. India’s indigenous livestock diversity includes about 27 breeds of catties, 40 breeds of sheep, 22 of goats, 8 of camels, 6 of horses, 2 of donkeys and 18 types of poultry. Eight indiginious breeds of buffalo in India represent the entire range of genetic diversity on the earth. These prized plants and animals together with their ancestral wild forms are used by plant and animal breeders for the development of improved varieties.
Biodiversity can be measured in different ways. Two main factors taken into account when measuring diversity are richness and evenness. Species richness is the number of different species present in an area. However , diversity depends not only on richness but also on evenness. Evenness compares the similarity of the population size of each of the species present. Evenness is a measure of the relative abundance of the different species making up the richness of an area.
India occupies only 2.4 percent of the world’s land area but its contribution to the world’s biodiversity is approximately 8 % of the total number of species, which is estimated to be 1.75 million. Based on the available data, India ranks 10th in the world. The ten important biogeographically zones having rich biodiversity are:
1. Trans-Himalayas
2. Himalayas
3. Desert
4. Western Ghats
5. Deccan Peninsula
6. Gangetic Plain
7. North-East India
8. Islands
9. Coastal Parts
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