The term’Biodiversity’ was introduced by an American Biologist EdwardWilson.Biodiversity is that part of nature which includes the differences ingenes among the individuals of the species. It represents the totality of genes, species,and ecosystem of a given region.
Thebiological diversity includes three inter-related hierarchical levels :GeneticDiversity SpeciesDiversityEcologicalDiversityGENETICDIVERSITY Thegenetic variation existing within a species is called genetic diversity. Thevariation may be in alleles, total genes or chromosome structuresSPECIESDIVERSITY Thediversity at the species level is called species diversity. Example:- TheWestern Ghats have a greater amphibian species diversity than the EasternGhats.
The species diversity depends upon the number and richness of thespecies of a region. Species richness – The number of species per unit area.ECOLOGICALDIVERSITY Thediversity at the ecosystem level is called ecological diversity.
Example:Deserts, rainforests, mangroves, coral reefs, wetlands, estuary and alpinemeadows etc.Valueof Bio-diversityBiodiversityprovides a variety of environmental services from its species and ecosystemsthat are essential at the globe, regional and local levels. The production ofoxygen, reduction of carbon dioxide, maintenance of the water cycle andprotection of the soil are some important services.It isalso important for preserving ecological processes, such as fixing and recyclingof nutrients, soil formation, circulation and cleansing of air and water. Food,clothing, housing, energy, and medicines are all resources that are directly orindirectly linked to the biological variety present in the biosphere. Tribalcommunities depend on the forest for resources. For Agricultural communities,biodiversity is used to grow crops.
Urban communities also use the greatestamount of goods and services which are drawn from natural ecosystems.Thuspreservation of biodiversity is the integrated strategy that aims at improvingthe quality of human life.ConsumableUse: Example forthis is timber, food, fuelwood.
The biodiversity in the ecosystem provide allthese goods. ProductiveUse: Thisincludes the marketable goods. The biotechnologist uses bio-rich areas forpotential genetic properties in plants and animals that can be used to developbetter varieties of crops for farming and plantation. To the pharmacist,biological diversity is the raw material from which new drugs can make from plantsor animal products. To industrialists, biodiversity is a rich storehouse fromwhich to develop new products. For an agricultural scientist, the biodiversityin the wild relatives of crop plants is the basis for developing better crops.SocialValue:Biodiversity has been preserved by traditional societies that valued it as aresource and appreciated that its depletion would be the great loss to theirsociety.
For example, many plants and animals are worshipped in India likeTulsi, Peepal, Cow, Snake etcMoralValue: Moralvalues in relation to biodiversity conservation is based on the importance ofprotecting all forms of life. We do not have the right to destroy any liferather the duty of ours is to protect life.AestheticValue: Theappreciation of the presence of biodiversity for its inherent value and beautyas well as for the contribution it makes to our knowledge- our aesthetics,imagination.
Instead of killing wildlife for food, it is important as a touristattraction. Biodiversity is a beautiful and wonderful aspect of nature. Sittingin a forest and listening to the birds or watching a spider weaving web is anice feeling.Indiaas a nation of mega bio-diversity centerAmega-diverse country is one that harbors the majority of the Earth’s speciesand is therefore considered extremely biodiverse. India is rich in biodiversityfrom north to south and from east to west.
India is in the top of 10 or 15countries for its great variety of plants and animals, many of which are notfound elsewhere. India has 350 different mammals, 1200 species of birds, 453species of reptiles and 45000 plant species. India has 50000 species of insectsincluding 13000 butterflies and moths. The unknown species are several timeshigher than this.
Besidesthe high biodiversity in Indian wild plants and animals, there is also a greatdiversity of cultivated crops and breeds of domestic livestock. There are 30000to 50000 varieties of rice and a number of cereals, vegetables, and fruits. Thehighest diversity of cultivars is concentrated in the high rainfall areas ofthe Western Ghats, Eastern Ghats, Northern Himalayas and Northeastern hills.The mountain range in Sikkim, Arunachal Pradesh, Nagaland, Manipur, Tripura,Mizoram and the Darjeeling hills are symbol of celestial splendor where a goodnumber of peaks rise well over 7000 m., the highest being the Kanchenjunga 8335m which is very close to Mt. Everest, the world highest peakAll thesefactors and much more are the reason behind why India is called a megabiodiversity center and makes it one of the seventeen mega biodiversitycountries of the world.Biodiversityat national and local levelsBiodiversityis the measure of the variety of earth’s animal, plant, and microbial species;of genetic differences within species; and of the ecosystems that support thespecies.
India hasover 108,276 species of bacteria, fungi, plants, and animals alreadyidentified. In terms of the number of species, the insects alone constitutenearly half of the biodiversity in India. In the world as a whole, 16, 04,000species of Monera, Protista, Fungi, Plantae, and Animalia have been describedso far. However, it is estimated that at least 179, 80,000 species exist in theworld, but as a working figure 122, 50,000 species are considered to be nearreality.
India is10th among the plant-rich countries of the world, fourth among the Asiancountries, eleventh according to the number of endemic species of highervertebrates (Amphibia, birds, and mammals), and tenth in the world as far asrichness in mammals is concerned. Out ofthe 10 ‘Hotspots’ identified in the world, India has four. These are EasternHimalaya, North East India, Western Ghats and Andaman & Nicobar Islands.Thecrops which first grew in India and spread throughout the world include rice,sugarcane, Asiatic vignas, jute, mango, citrus, and banana, several species ofmillets, spices, medicinal, aromatics, and ornamentals. India ranks sixth amongthe centers of diversity and origin in terms of agro-biodiversity.Threatsto Bio-diversityLossof habitat: Humanactivities are causing a loss of biological diversity among animals and plantsglobally estimated at 50 to 100 times the average rate.
Tropical forests areunder threat largely from conversion to other land-uses, while coral reefs areexperiencing increasing levels of over-exploitation and pollution. If thecurrent rate of loss of tropical forests continues for the next 30 years. Poachingof wildlife:Poaching means illegal hunting or killing of wildlife. The dead animals are oflarge economic benefits. The skins and bones of the tiger, ivory of elephants,horns of rhinos are largely used abroad. Corals and shells are collected forexports and sold on the beaches of Chennai, Kanyakumari and Andaman and Nicobarislands.
A variety of wild plants are used for medical values.Manwildlife conflicts:We generally lose the species because of the destruction of natural ecosystems,either for conversion to agriculture or industry, or overuse of resources orthrough pollution of air, water, and soil. The natural forests are deforestedfor timber and replanted using teak, sal for their timber value.
Suchmonoculture plantations do not support the biological diversity.