Essay About Biodiversity Conservation Ppt
Here is a compilation of essays on ‘Biodiversity’ for class 6, 7, 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Biodiversity’ especially written for school and college students.
Essay on Biodiversity
- Essay on the Introduction to Biodiversity
- Essay on the Levels or Components of Biodiversity
- Essay on Community Diversity
- Essay on the Gradients of Biodiversity
- Essay on the Range of Biological Diversity
- Essay on the Benefits/Uses of Biodiversity
- Essay on the Causes of Extinction of Biodiversity
- Essay on the Conservation of Biodiversity
Essay # 1. Introduction to Biodiversity:
The term biological diversity or biodiversity refers to the variety of life forms and habitats found in a defined area. UNEP (1992) defines it “as the variety and variability of all animals, plants and micro-organisms andthe ecological complexes of which they are a part”. The term biodiversity was coined by W.G. Rosen (1985). Diversity characterizes most living organisms, the our earth supports something like 5 to 10 million species of plants and animals (IUCN, 1980) which have been the result of 3 billion years of evolution involving mutation, recombination and natural selection.
Biodiversity is an umbrella term covering diversity at genetic, species and ecosystem level. The convention on Biological Diversity defines biodiversity as “The variability among living organisms form all sources including, interalia terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems.” In short it refers to the whole variety of life on earth.’ Biodiversity represents the totality of genes, species and ecosystems of a region.
Essay # 2. Levels or Components of Biodiversity:
Biodiversity is said to have three (hierarchical) levels, or components:
a. Ecological (Ecosystem) Diversity:
The diversity of ecological complexes or biotic communities found in a given area. Indian ecosystem diversity is described at each of the three levels (biogeographical region, biotic province and biome). Largest of identified ecosystems has been the biogeographical zone. The vast area covered by biogeographical zone contains a wide diversity of smaller units called biotic provinces.
Finally, within each biotic province, various kinds of biomes are distinguished. Biome classification broadly follows commonly used terminology, distinguishing between forests, grasslands, wetlands, deserts, and other such ecosystems on the basis of their physical appearance and dominant biotic or abiotic element. The enormous range of terrestrial and aquatic environments on earth has been classified into number of ecosystems.
Few examples are:
(i) Tropical rain forests,
(ii) Grasslands, and
Ecosystems differ not only in the species composition of their communities but also in their physical structures (including the structures created by organisms). Some of the world’s richest habitats are tropical moist forests. Although they cover only 7% of the world’s surface, these areas contain atleast 50%, and possibly upto 90% of all plant and animal species.
b. Species Diversity:
Species diversity refers to variety of species in a region. Number of species per unit area is called species richness. Eveness or equitability differs due to difference in number of individuals in an area.
With increase in area, number of species increase. Usually, species diversity increases, if species richness is higher. Somehow, number of individuals among species may differ. This may lead to differences in evenness or equatibility. This also results to change in diversity. Some examples are as under (Fig. 15.1).
(i) Suppose in an area -1, there are three species of bird. Out of them two species bear only one bird each. Third species has four birds.
(ii) In area -2, there are 3 species each having 2 birds. This area represents greater evenness. It is more diverse than area.
(iii) In area-3, an insect, a mammal and a bird is also present.
The diversity of populations of organisms which interbreed or are reproductively isolated from other such populations. Species are the most commonly used unit describing biodiversity. Comparisons of the diversity found in different countries or ecosystems, for instance, are almost always based on species number.
According to investigations into Amazoruan rainforest canopy, worldwide, some 5 to 30 million species are believed to exist. Nearly 1.7 million have so far been described. Species diversity has frequently been used as an indicator of the conservation significance of an area.
c. Genetic Diversity:
The diversity of basic units of hereditary information (genes) which are passed down the generations, found within a species is genetic diversity. Genetic diversity refers to variation of genes within species. The genetic diversity within a species is expressed by many terms, subspecies, breeds, races, varieties and forms. This diversity arises from “variations in the sequence of four base pairs which as component of nucleicacids which constitute the genetic code.”
Genetic information is stored in genes. In Mycoplasma, there are about 450-700 genes; in Escherichia coli 3200, in Drosophila melanogaster 13000, in Oryza sativa 32,000-50,000 and in Homo sapiens the number of genes ranges in between 31000 and 45000. Due to genetic diversity, population adjusts in its environment and responds to natural selection.
More the genetic diversity in an organism, better is the adaptation to changed environmental conditions. A sort of uniformity is obtained with lower genetic diversity. This happens with large monocultures of genetically similar crops. This condition is considered to be better for increased production of crops. However, it may create a problem when crops are attacked by insects or fungal disease. Genetic variation leads to evolution of new species (speciation).
Genetic variations occur to varying degrees in most species of plants and animals. There is high genetic variation in Indian rhinos but little in cheetahs. This variety of genetic material within species has enabled distinct species to evolve through natural selection.
Essay # 3. Community Diversity:
This demarcates three levels of components:
a. Alpha Diversity (with in community diversity):
It represents number of species in a given habitat. It represents the diversity of organisms sharing the same community/habitat. A combination of equitability/evenness and species richness is used to know that diversity prevalent within community or habitat.
Differences can be observed in species composition of communities along different environmental ranges like moisture gradient, altitudinal gradients, etc. Beta diversity will be always high with increase in heterogeneity in habitats in a region or with higher dissimilarity found between communities.
b. Beta Diversity (between community diversity):
The rate of turnover or replacement of species while moving from one habitat to another within a given geographical area. For instance the differences in species composition between a coral reef and the adjoining intertidal zone would be termed as beta diversity.
c. Gamma Diversity:
This term is used for the rate of turnover or replacement of species between similar habitats in different geographical areas. For example, the differences in species; composition between the coral reef in the Gulf of Kutch and in the Andaman Islands would be called as gamma diversity. Diversity of habitats are the total landscape or geographical area is called gamma diversity.
Essay # 4. Gradients of Biodiversity:
Change in latitude or altitude leads to change in biodiversity. Biodiversity increases from poles to equator (from high to low latitude). Number of species increase in area with favourable environmental conditions (e.g. in tropical rain forests). In temperate regions, plants grow for shorter period due to adverse climatic conditions.
For example vascular plants in tropic rain forests are 118-236 per 0.1 ha sample area when compared with temperate zones (only 21-48 species). It has been found to be true with other taxonomic groups like arts (Fig. 15.3), birds, butterflies, etc., can be noticed.
On mountains, decrease in species diversity takes place from lower to higher altitude. Higher seasonal variations and fall in temperature leads to reduction in biodiversity with 1000 m increase in altitude leads to temperature drop of about 6.5°C.
Essay # 5. Range of Biological Diversity:
The present day life probably constitutes about 1% of the total that has existed on this planet so far. Natural extinction is part of the overall evolutionary process. The present wave 0.1 extinction is essentially man-made due to the ever-increasing needs (or greed) of human kind. There is an ecological crisis which has threatened the whole life support system and the large number of habitats and species, both plant and animal, have been progressively on the decline.
Thus humankind is involved in what has been called specie. If genocide is a crime, specie is equally so. Charka the physician was asked by his teacher to get him a plant that was quite useless, he returned empty handed saying that there was no such plant.
One cannot imagine asituation, if Penicillium had been eliminated from earth before humankind made use at it as an antibiotic or if Cinchona become extinct before quinine was discovered as a cure for malaria. It is, therefore, in our interest to conserve our plant as also animal and micro-organism wealth. There is a growing realisation throughout the world about the urgent need to conserve the biological diversity.
Living resources conservation has three specific objectives:
1. To maintain essential ecological processes and life support system.
2. To preserve biological diversity.
3. To ensure that any utilisation of species and ecosystems is sustainable.
Biological diversity includes two related concepts genetic diversity and ecological diversity.
Genetic diversity is the amount of genetic variability among individuals of a single species as also between species.
Ecosystem diversity or Ecological diversity (species richness) is the number of species in a community of organisms. The Indian regions (8°-30°N and 60°-97.5°E) with a total area of 329 million is indeed very rich in biological diversity. The total plant wealth of the country includes not only the usually large showy flowered vascular plants, but a large number of non-flowering plants such as ferns, liverworts, algae and fungi. The endemic species and genera are largely concentrated in two principal biogeographical regions of India i.e. Himalyas (about 42,000 species) and Pennisulai India (about 2,600 species).
Ecosystem diversity informs the number of riches, trophic levels and ecological systems like energy flow, food webs and recycling of nutrients. Diverse communities are more stable and productive. They can tolerate environmental stresses like prolonged dry conditions. Number of habitats and ecosystems observed in an area is also a criterion for measuring biodiversity. Some important ecosystems are savarmas, rain forests, deserts, lakes, wetlands and oceans.
There is a much variety of fauna and flora in the oceans. India has a coastline of about 6,000 km. with an area of 20, 13, 410 sq. km. of exclusive economic zone (EEZ) and a shelf area of 4,52,060 sq. km. The main reason for this remarkable diversity of life forms in a single country is the great diversity of ecosystems, which it has supported down the ages.
Equally important are the micro-organisms like fungi and bacteria which are very important component of biosphere in as much as they are responsible for degradation of the dead biomass and release of nutrients, which are assimilable by plants and animals and enrich soil, as also form humus.
In Fig. 15.5 various biogeographical regions of India have been represented. Some noteworthy features of these regions are:
(i) Deccan Penisula covers 42 per cent of Indian landmass.
(ii) Western Ghats (4 per cent). North-east (5.2 per cent) are most biodiversity rich regions.
(iii) Every bio-geographic region has several habitats, many biotic communities and ecosystems.
(iv) Indian region is significant in the sense that many flowering plants and animals are endemic. About 33 per cent flowering plants, 53 per cent freshwater fish, 60 per cent amphibians, 36 per cent reptiles and 10 per cent mammals found in India are endemic.
(v) Most of the species found are either endemic or exclusive to India.
(vi) Western Ghats, North-east, North-west Himalaya, Andaman and Nicobar Islands are richest in endemics.
(vii) Lot of work is still required to be carried out for exploring the biodiversity in India. Such areas include wetlands, lakes, oceans, tree canopy and soil of tropical rain forests.
There is an urgent need to arrest species extinction. Equally important is the need to prevent the loss of thousands of years of human selection in crop species and domesticated animals for posterity.
Essay # 6. Benefits/Uses of Biodiversity:
Biodiversity or its physical manifestation-the biological resources are the basis of life on earth. Ecosystem provides a variety of goods and other services- immediate as well as long term material which are vital to our well being. Countries having greater biodiversity have better potential to compete with rest of the world in global market for search of genes and species with potential uses. The value of biodiversity in terms of its commercial utility, ecological services, social and aesthetic value is enormous.
Biodiversity has great importance to mankind due to its many uses:
1. Ecosystem (ecological) Role of Biodiversity:
All the living organisms are so closely interlinked (through food chain, food webs, material cycling, energy flow, etc.) that destruction of one kind of wildlife on the earth may upset the ecological balance in nature e.g., destruction of snakes will lead to increase in the rat population which will destroy crops.
Similarly, killing of carnivores will increase the population of herbivores which will damage the vegetation and disturb the ecological balance. Species of plants and animals keep a check on their numbers through food chains, so the wildlife helps to preserve the environment as a self-sustaining system. Thus, ecosystems often support and provide services like soil fertility, plant pollinators, predators, decomposers, purification of air and water, management of flood and drought and other environmental disasters.
Biodiversity is required for maintaining and sustainable use of goods and services from ecosystems. These services are maintenance of gaseous composition in atmosphere, pollination, formation of soil, nutrient cycling, climate control by forests and oceanic systems. Such services will otherwise cost 16 to 54 trillion (1012) US dollars per year.
Ecosystems with more biodiversity can withstand the environmental challenges in a better way because genetically variability leads to different tolerance range for a specific environmental stress. Due to this single stress cannot eliminate them easily; Thus species with higher genetic biodiversity have better adaptation ability towards environmental disturbances.
2. Scientific Importance:
Wildlife acts as a source of gene bank for breeding programmes in agriculture, animal husbandry, fisheries, etc., e.g., fruit flies, frogs, rats, rabbit, guinea pigs, rhesus monkeys and many
Other wild animals are used as research materials on which drugs are tested before applying to mankind. Plant breeders have produced a number of high-yielding and disease-resistant varieties from their wild relatives by genetic modifications. So there is an urgent need to protect wildlife for breeding experiments. The wildlife acts as a source for new varieties.
The protection of wild life becomes of paramount importance for their survival and propagation of race, so man is constantly in search of ways and means of preserving natural areas in their natural conditions to promote the development of wildlife e.g., man was able to save the high-yielding varieties of rice to protect them from a new rice pest Nilaparvata lugens (brown plant hopper) by introducing pest-resistant gene in them from a few wild varieties found in Kerala.
Similarly, wild rice (Oryza nivara) provided resistance against grassy stunt virus in 1970s when virus- resistant gene was incorporated in IR-36 rice variety; Wild Thatch Grass (Saccharum sponataneum) provided resistant gene to sugarcane against red rot disease; similarly in potato, resistant gene against late blight disease has been incorporated from a wild variety – Solarium demissum. Thus the production of high-yielding, disease-resistant crops, livestocks and fish cannot withstand the changes of the surrounding without their wild relatives.
3. Drugs and Medicine:
About 75% of world’s population depends upon plants or plant extracts for medicines.
Some examples of drugs and medicenes extracted from plants are:
(i) Morphine (Papaver somniferum) is used as analgesic.
(ii) Quinine (Chinchona ledgeriana) for treatment of malaria.
(iii) Taxol extracted from bark of Taxus brevifolia and T. baccata is used as anticancer drug.
(iv) Penicillin used as antibiotic is derived from a fungus called Penicillium.
(v) Tetracyclin is got from a bacterium.
(vi) Digitalin a drug used for cure of heart ailments is got from Digitalis.
Plants are also useful for making many synthetic products called botanochemicals. Twenty five per cent of drugs in pharmacy are got from only about 120 species of plants. About seventy five per cent of anticancer drugs are derived from plants found in tropical rainforests. The medicinal benefits are not only limited to plant compounds. A host of microbial, anti-viral, cardio active and neuro-physiologic substances have been derived from poisonous marine fauna. The venoms of various arthropods have medicinal potential.
One of the most fundamental values of biodiversity is in providing food. It is obtained from sources like livestock, forestry and fish. Originally plants were consumed directly from wild habitats. Gradually, most of them were grown as agriculture. More than 80,000 species of plants are used as food. About 4,000 native plant and animal species are used by villagers in Indonesia for food and medicine.
Fresh-water and marine fishes provide large amount of food.
Biodiversity in modern agriculture is beneficial due to:
(i) For breeding, biodiversity provides source material.
(ii) As a source of new biodegradable pesticides.
(iii) As a source of new crops.
Plants provide food not only for themselves but also for other organisms including man. About 20 plant species are used which provide about 85 per cent of world’s food.
Just three crops i.e. wheat, rice and maize account for about 60% of the calories and about 55% of protein in humans consume come directly from plants. Global fish production exceeds that of cattle, sheep, and poultry. It is the largest source of either world or domestic animal protein in the world. Virtually 100% of the protein from domesticated animals comes from nine species i.e. cattle, pigs, sheep, goats, water buffaloes, chickens, ducks, geese and turkeys.
5. Industrial Importance:
Wildlife is a renewable source and is beneficial to mankind in many ways:
(a) Fur, skin and other products like musk, leather, honey, lac, cochineal (a red pigment), guano, pearls, etc. obtained from wild animals are sources of trade.
(b) Ivory of elephants, horns of rhino, antlers of deer, etc. fetch large amount of money in foreign currency market. In fact, tourist industry of Kenya is based on its wildlife.
(c) Several wild plants provide useful products like timber, paper, gums, resins, tannins, dry fruits, fibres (cotton, jute), drinks (tea, coffee), distillation products like wood alcohol, acetic acid, oxalic acid, charcoal, and medicines, etc.
6. Aesthetic and Cultural Importance:
Due to their beauty, many birds, variously colourful butterflies, mammals, green forests etc. have great aesthetic value to human beings.
Aesthetic pleasure derived from biodiversity includes bird watching, pet keeping, gardening, wild life sanctuaries etc.
Many plants are considered sacred and even worshipped in India e.g. Ficus religiosa (peepal), Ocitnum sanctum (Tulsi) and Prosopis cineraria (Khejiri). Many animals like birds and snakes are also worshipped.
The value put to aesthetic function of nature is reflected in creation of millions of small home gardens, several community gardens, botanical gardens, zoos, aquariums established in different states. Growing up in degraded environments, could result in the development of negative attitudes in human populations.
7. Unknown Benefits:
A wild species may have certain benefits which are still not known to us and may become known in future. So the conservation of even non-beneficial species is equally significant e.g., isolation of penicillin from Penicillium notatum (blue-green mould); anti-malarial drug- quinine from the bark of Cinchona plant of Peru; and natural silk from the silk moth — Bombyx mori, etc., were not known from the very beginning.
8. Sport and Enjoyment:
Wildlife is also important in games so are hunted upon while some of them are even worshipped. A visit to the sanctuaries and national parks is a thrilling experience. Some animals are used for recreation of people in circus shows.
9. Ethical Needs:
The present wild life is the result of organic evolution which started about 3.5 billion years ago. So it is our ethical duty to conserve the wildlife for the utilization of coming generations.
10. Religious Importance:
Different animals are symbolized as the vahanas of Hindu gods/goddesses e.g., garuda for Lord Vishnu; bull for Ishwara; mouse for ‘Ganpathy; peacock for Subramaniyam; tiger for Goddess Durga, etc. There are many animal gods as well like Matsya, Narsimha and Hanuman.
Essay # 7. Causes of Extinction of Biodiversity:
Extinction is the complete elimination of a wild species:
It is a natural but slow process but due to unplanned activities of man, the rate of decline of wild life has been particularly rapid in the last one hundred years. India alone has a total of 459 threatened species of which include 86 mammals, 70 birds, 25 reptiles, 3 amphibians, 8 fishes, 23 invertebrates and 244 plants. The biological diversity of ecosystems like Wayanad, Kolli Hills, Jeypore Tract, Bhitarkanika, Lakshadweep Islands, Arunachal Pradesh and Mizoram is under threat because of conflict between food security of population living therein and biodiversity conservation.
There are a number of causes which are known to cause extinction of wildlife:
1. Destruction of Habitats and Fragmentation:
It is the most serious threat to wildlife.
(a) Pollution due to automobiles, etc. leading to degradation of a number of important habitats.
(b) Deforestation leads to decrease in the area of movement so decreasing their reproductive powers. In Tripura, deforestation of dense forests is posing a serious threat to the precious barbe’s leaf monkey, better known as “spectacled monkey” or “lajvanti bandar” (shy- monkey). Main causes of its facing extinction are increasing destruction of its habitat, by deforestation coupled with jhum and shifting cultivation.
(c) Soil erosipn.
(d) Agricultural expansion.
(f) Increasing urbanisation
(g) Forest fires due to certain human activities or by chance.
(h) Development works like dams, reservoirs, roads, railway lines, croplands, industries, mines, etc. Dams block spawning and migration of certain fishes.
(i) Cleanliness drives adversely affect the natural scavengers like Cathartes californianus—California. candox (a shy scavenger and largest fly bird of today).
Destruction of habitat is very serious threat to our wildlife because:
(a) It decreases the hiding places of animals, and
(b) It increases the chances of their predation.
(j) A forest area surrounded by urban colonies, orchards, plantations, and cropland represent fragmented habitats. Due to this species present in deeper areas start disappearing.
The declaration of common Hippopotamus (Hippopotamus amphibius) as endangered species in 2006 Redlist is primarily due to habitat loss and its over exploitation for meat and ivory.
(k) Fragmentation is the process of reduction of habitat into smaller and scattered areas. Animals like elephants, lions, bears and large cats require bigger areas to survive and more. Few birds can reproduce only in deep forests.
Due to habitat fragmentation following effects can be observed:
(a) Due to habitat fragmentation, barriers are created which limit the potential of species for proper dispersal and colonisation,
(b) This leads to formation of smaller populations which are not able to sustain.
(c) Migratory birds do not move to scattered seasonal patches.
(d) Species become more vulnerable to wind, fire and predators.
2. Indiscriminate hunting for various uses of animals like food, hide, musk, tusk, horn, fur, plumage, recreation, etc. Other causes of indiscriminate hunting of wild animals are: their increased demand as museum specimens and increased trade for the animal products like hides, skins, fur, leather, feathers, horns, ivory, meat, etc. Excessive hunting is known to cause.
(a) Extinction of Dodo bird (Didus ineptus-extensively killed due to its beautiful feathers) of Mauritius.
(b) Extinction of Cheetah (Acinomyx jubatus), the fastest mammal of India. (Last live cheetah died in Delhi Zoo in 1994).
(c) Many species of fish, molluscs, sea-turtles, and whales are facing extinction.
According to a report of WPSI (Wildlife Protection Society of India), more than 60 tigers have been poached in different parts of the country during the year 1994- 95. A London based international conservation organisation has stated that poaching of tigers for Chinese medicines, is responsible for the death of at least one tiger in India every day. According to another report, rhino poaching in and around Kaziranga National Park has increased and 25 rhinos have been poached in 1995.
In Orissa, many wildlife species including Asian elephant face imminent danger of extermination because of poaching and lack of concern by the Government to check trafficking of wild animals. Wildlife Society of Orissa has reported that 57 elephants have been shot dead by poachers for ivory between 1992-96.
Strict action by Rajasthan Government coupled with quick judicial pronouncements (in October, 1998) in the cases related to two black bucks by cine star Salman Khan and his accomplices has clearly sent a message that howsoever highly placed one might be, no one can escape the due process of law when it comes to the crime of killing the wild animals. Between 1995 and 2000, about 175 lions and 226 tigers died in Indian zoos as against 46 lions and 142 tigers in the ‘protected areas’.
3. Introduction of exotic (alien) species are known to threaten the survival of many native species e.g.;
(a) Periplaneta Americana (American cockroach) is threatening the existence of native oriental cockroach, Blatta orientalis.
(b) Exotic trout and bass are affecting many species in USA.
(c) Large scale killing of American chestnut tree by an exotic fungus species, Endothia parasitica (chestnut blight) of China. The fungus was accidentally introduced into the United States in 1904.
(d) Goats and rabbits introduced in the islands of Pacific and Indian Oceans are destroying the habitats of several plants, birds and reptiles.
(e) Eupatorium odoratum replaced Tectona grandis in N.E. India.
(f) Parthenium hysterophorus (carrot grass) has replaced herbs and shrubs in open spaces.
(g) Eichhornia cmssipes (water hyacinth) has become dominant species in pools and ponds. It is a nuisance weed in many eutrophic (nutrient rich) lakes and rivers in tropical countries like India where it does not allow other plants to grow and multiply properly.
(h) Nile perch, an exotic predatory fish introduced in Lake Victoria of South Africa has eliminated several native small cichlid fish species which were endemic to this lake.
(i) Lantana camara, a plant now has entered into forests and seriously competing with native species growing there.
These exotic species are known to adversely affect the native species through factors like: competition for food and space, predation, habitat destruction, transmission of diseases and parasites.
4. Over-exploitation of natural resources e.g., overfishing, mechanical catching of animal species, etc., is a serious threat to the wildlife.
5. Disturbance in migratory routes of animals like fishes due to construction of dams, etc., so these are not able to reach their spawning grounds and face extinction.
6. International trade in increasingly scarce animal products like medicines, perfumes, cosmetics, decoration, museum specimens, etc., is the cause of destruction of many species e.g., musk-deer (Moschus moschiferus) and great one-homed rhinoceros (Rhinoceros unicornis) in India are being extensively killed for the medicinal importance of their musk and rhino-horn respectively.
7. Highways. A number of wild animals get confused and are run-over by the vehicles on the highways so decreasing their number.
8. Lack of education. Majority of Indian people are not aware of the importance of wildlife and ill effects of its destruction. So the people must be educated to save the wildlife.
9. Official laxity in the implementation of Wildlife (Protection) Act.
Most of the destruction of wildlife is avoidable.
10. Environmental pollution. Large scale use of synthetic compounds release of radioactive chemicals, oil spills are polluting the rivers and reducing the species number. This leads to elimination of sensitive species and proliferation of tolerant organisms.
Due to accumulation of pesticides, DDT, PCBs and dioxins, in Atlantic, decline in fish eating birds and wide spread deaths of seals has been observed. Lead poisoning is also causing death of many wild life species. Bottom feeding water birds like ducks ingest shotgun pellets that fall into lakes and marshes and 2-3 million of die every year due to lead poisoning.
Essay # 8. Conservation of Biodiversity:
It is the management of the biosphere in such a way that it may yield the greatest sustainable benefit to present generation while maintaining its potential to meet the needs and aspirations of future generations.
So wildlife conservation involves the management of not only the living organisms but also the abiotic factors of the environment so as to maintain the life- supporting systems of the wildlife.
Three specific objectives for the conservation of wildlife are:
(a) To maintain essential ecological processes and life-supporting systems (air, water and soil).
(b) To preserve the diversity of species or the range of genetic material of world’s organisms.
(c) To ensure a continuous (everlasting) use of species, infact ecosystems, which support rural communities and urban industries?
A comprehensive World Conservation Strategy for the judicious use of natural resources has been formulated by the scientists from 100 countries of the world.
Some of the proposed steps to protect the wildlife are:
(a) Protection of useful animals and plants, and their wild relatives both in their natural habitat (in situ) and in zoological and botanical gardens (ex situ).
(b) Preservation of critical habitats (the feeding, breeding, nursery and resting areas) of the plant and animal species to promote their growth and multiplication.
(c) Priority should be given in wildlife conservation programme to an endangered species over a vulnerable species, and to a vulnerable species over a rare species.
(d) The management of life-supporting systems (air, water, land) of the wildlife.
(e) Hunting should be regulated and it should involve the following steps:
(i) Only licensed persons should be allowed to hunt.
(ii) Hunting of young animals should not be allowed.
(iii) Hunting in breeding season should be banned.
(iv) Hunting of threatened species should also be banned.
(v) A limit should be imposed on the number of animals to be hunted upon.
(f) The habitats of migratory animals should be protected by bilateral or multilateral agreements.
(g) International trade in useful products of wild plants and animals should be regulated. India is a signatory to the “Convention on International Trade in Endangered Species of Wild Fauna and Flora”. Recently, a protocol has been signed by India and China to coordinate their efforts to combat illegal poaching of tigers and smuggling of tiger bones and other parts of its body.
(h) Educating the people about the importance of wildlife and its conservation.
(i) Over-exploitation of useful products of wildlife should be avoided.
(j) The species and ecosystems should not be exploited beyond their productive capacities. The unique ecosystems should be protected on priority basis.
(k) National Parks and sanctuaries should be set up to protect wildlife. This will safeguard the genetic diversity of species and their continuing evolution.
(l) The Indian Wildlife (Protection) Act, 1992 provides legal measures for the protection of wild animals. It prohibits the hunting of all wildlife specified in schedules I, II, III and IV of the Act.
To prevent further deterioration and extinction of useful wildlife, the national conservation programmes should be coordinated with the international programmes, especially those of UNESCO (United Nations Educational, Scientific and Cultural Organization) and IUCN (International Union for Conservation of Nature and Natural Resources). To aware the people about the importance of birds, Haryana state has named all its tourist resorts after the name of birds.
Scientists of Cellular and Molecular Biology, Hyderabad have suggested that creation of In vitro Fertilization (IVF) facilities in the country was the only way to preserve the endangered species. China has set up such facilities for Giant Panda and other endangered species in Chengdu.
Status of Threatened Species:
i. About 11,046 species (5485 animals and 5611 plants) have been considered as threatened in 2000 Red List.
ii. Critically endangered species are 1939 in number, out of which 925 are animals and 1,014 are plants. In angrosperms and vertebrates 9-16 percent are critically endangered, 34-51 per cent are vulnerable.
The term biodiversity was coined as a contraction of biological diversity by E.O. Wilson in 1985. Biodiversity may be defined as the variety and variability of living organisms and the ecological complexes in which they exist. In other words, biodiversity is the occurrence of different types of ecosystems, different species of organisms with the whole range of their variants and genes adapted to different climates, environments along with their interactions and processes.
Biodiversity includes the genetic variability (forwhich different varieties of spices have appeared in the course of evolution) and diversity of life forms such as plants, animal microbes, etc. living in a wide range of ecosystems.
1. Types of Biodiversity
2. Biodiversity of India
3. Importance of Biodiversity
4. Uses of Biodiversity
5. Threats to Biodiversity
6. Conservation of Biodiversity
The diversity may be interspecific (within species) and interspecific (in betweenthe species) but these are well supported by ecosystem. It is seen that the diverse living forms of the ecosystem are modulated with the global environmental changes.
1. Types of Biodiversity:
There are three interrelated hierarchical levels of biodiversity namely, genetic diversity, species diversity and community or ecosystem diversity.
The discussion on each type of diversity is given below:
1. Genetic diversity:
It describes the variation in the number and types of genes as well as chromosomes present in different species. The magnitude of variation in genes of a species increases with increase in size and environmental parameters of the habitat.
The genetic variation arises by gene and chromosome mutation in individuals and in sexually reproducing organisms and it is spread in the population by recombination of genetic materials during cell division after sexual reproduction.
Genetic diversity has the following importance:
(i) It helps in speciation or evolution of new species;
(ii) It is useful in adaptation to changes in environmental conditions;
(iii) It is important for agricultural productivity and development.
2. Species diversity:
It describes the variety in the number and richness of the spices with in a region. The species richness may be defined as the number of species per unit area. The richness of a species tells about the extent of biodiversity of a site and provides a means for comparing different sites.
The species richness depends largely on climatic conditions. The number of individuals of different species with in a region represents species evenness or species equitability. The product species richness and species evenness give species diversity of aregion. When a species is confined entirely to a particular area, it is termed as endemic species.
3. Ecosystem diversity:
It describes the assemblage and Interaction of spices living together and the physical environment a given area. It relates varieties of habitats, biotic communities ecological processes in biosphere. It also tells about the diversity within the ecosystem. It is referred as Land escape diversity because it includes placement and size of various ecosystems.
For example, the landscapes like grass lands, deserts, mountains etc. show ecosystem diversity. The ecosystem diversity is due to diversity of niches, trophic levels and ecological processes like nutrient cycling, food webs, energy flow, role of dominant species and various related biotic interactions. Such type of diversity can generate more productive and stable ecosystems or communities capable of tolerating various types of stresses e.g. drought, flood etc.
According to Whittaker (1965), the community diversities are of three types:
It tells the species diversity in a given community.
It depends upon species richness and evenness.
It describes a range of communities due to replacement of species which arises due to the presence of different microhabitats, niches and environmental conditions.
(iii) γ -Diversity:
It describes diversity of habitat over a total land escape or geographical area.
2. Biodiversity of India:
As per available data, the varieties of species living on the earth are 1753739. Out of the above species, 134781 are residing in India although surface area of India is 2% of the earth’s surface. Wild life Institute of India has divided it into ten biogeographical regions and twenty five biotic provinces.
Biogeographical regions are:
(i) Trans Himalayas,
(ii) Gangetic plain,
(iv) Semiarid zone;
(v) Western Ghats;
(vi) Deccan peninsula,
(vii) North eastern zone,
(viii) Coastal lands
India is one of the twelve mega diversity nations of the world due to the following reasons:
(i) It has 7.3% of the global fauna and 10.88% of global flora as per the data collected by Ministry of Environment and forest.
(ii) It has 350 different mammals, 1200 species of birds- 453 different reptiles, 182 amphibians and 45,000 plants spices.
(iii) It has 50,000 known species of insects which include 13,000 butterflies and moths.
(iv) It has 10 different biogeographical regions and 25 biotic provinces having varieties of lands and species.
(v) In addition to geographical distribution, geological events in the land mass provide high level of biological diversity.
(vi) Several crops arose in the country and spread throughout the world.
(vii) There is wide variety of domestic animals like cows, buffaloes, goats, sheep, pigs, horses etc.
(viii) The marine biota includes sea weeds, fishes, crustaceans, molluses, corals, reptiles etc.
(ix) There are a number of hot spots (namely Eastern Ghats, Western Ghats, North Eastern hills etc.).
3. Importance of Biodiversity:
The living organisms on earth are of great diversity, living in diverse habitats and possessing diverse qualities and are vital to human existence providing food, shelter, clothing’s, medicines etc.
The biodiversity has the following importance’s:
1. Productive values:
Biodiversity produces a number of products harvested from nature and sold in commercial markets. Indirectly it provides economic benefits to people which include water quality soil protection, equalisation of climate, environmental monitoring, scientific research, recreation etc.
2. Consumptive value:
The consumptive value can be assigned to goods such as fuel woods, leaves, forest products etc. which may be consumed locally and do not figure in national and international market.
3. Social value:
The loss of biodiversity directly influences the social life of the country possibly through influencing ecosystem functions (energy flow and biogeochemical cycle). This be easily understood by observing detrimental effects of global warming and acid rain which cause an unfavorable alteration in logical processes.
4. Aesthetic value:
Aesthetic values such as refreshing fragrance of the flowers, taste of berries, softness of mossed, melodious songs of birds, etc. compel the human beings to preserve them. The earth’s natural beauty with its colour and hues, thick forest, and graceful beasts has inspired the human beings from their date of birth to take necessary steps for its maintenance. Similarly botanical and zoological gardens are the means of biodiversity conservation and are of aesthetic values.
5. Legal values:
Since earth is homeland of all living organisms, all have equal right to coexist on the surface of earth with all benefits. Unless some legal value is attached to biodiversity, it will not be possible to protect the rapid extinction of species.
6. Ethical value:
Biodiversity must be seen in the light of holding ethical value. Since man is the most intelligent amongst the living organisms, it should be prime responsibility and moral obligation of man to preserve and conserve other organisms which will directly or indirectly favour the existence of the man.
7. Ecological value:
Biodiversity holds great ecological value because it is indispensable to maintain the ecological balance. Any disturbance in the delicately fabricated ecological balance maintained by different organisms, will lead to severe problems, which may threaten the survival of human beings.
8. Economic value:
Biodiversity has great economic value because economic development depends upon efficient and economic management of biotic resources.
In the day to day life, human beings are maintaining their lifestyle at the sacrifice of surrounding species which come from diversity of plants and animals struggling for their existence.
So, it is highly essential for the human beings to take care of their surrounding species and make optimum use of their service, for better economic development. Thus, it is rightly told, survival of the man depends upon the survival of the biosphere.
4. Uses of Biodiversity:
Biodiversity has the following uses for the development humanity:
(i) It provides food of all types.
(ii) It provides fibers, sources for the preparation of clothes.
(iii) It provides different types of oil seeds for the preparation of oils.
(iv) It provides new varieties of rice, potato etc. through the process of hybridization.
(v) It provides different drugs and medicines which are based on different plant products.
(vi) It is very essential for natural pest control, maintenance of population of various species, pollination by insects and birds, nutrient cycling, conservation and purification of water, formation of soil etc. All these services together are valued 16.54 trillion dollars per year.
5. Threats to Biodiversity:
Biodiversity is considered as a reservoir of resources to be used for the manufacture of food, medicine, industrial products, etc. But with an increased demand of rapid population growth, biodiversity is gradually depleting. A number of plants” and animal species have already become extinct and many are endangered.
The different factors responsible for causing threat to biodiversity are as follows:
1. Habitat destruction:
The primary cause of loss of biodiversity is habitat loss or destruction which is resulted due to the large industrial and commercial activities associated with agriculture, irrigation, construction of dams, mining, fishing etc.
2. Habitat fragmentation:
With increased population, the habitats are fragmented into pieces by roads, fields, canals, power lines, towns etc. The isolated fragment of habitats restricts the potential of species for dispersal and colonization. In addition, the habitat fragmentation also brings about microclimatic changes inlight, temperature, wind etc.
The most dreaded factor inducing loss of biodiversity is environmental pollution which include air pollution, Water pollution, industrial pollution, pollution due to chemical Pastes, pesticides radioactive materials etc.
4. Over exploitation:
The natural resources are over exploited to meet growing rural poverty, intensive technological growth and globalization of economy. All these factors together may be responsible for the extinction of a number of species.
5. Introduction of exotic species:
The introduction of exotic species are due to:
(iii) European colonisation and
(iv) accidental transport.
It is seen that some exotic species may kill or eat the native species thereby causing its extinction.
Since the animals are more vulnerable to infection, the anthropological activities may increase the incidence of diseases in wild species, leading to their extinction.
7. Shifting or Jhum cultivation:
The shifting or Jhum cultivation by poor tribal people greatly affects the forest structure which is a store house of biodiversity.
8. Poaching of wild life:
A number of wildlife species are becoming extinct due to poaching and hunting.
Table 5.1: Endangered and Endemic Species of India
Category Enlisted species Highly endangered Species.
1. Higher plants
3. Reptiles and amphibians
6. Conservation of Biodiversity:
Biodiversity is being depleted by the loss of habitat, fragmentation of habitat, over exploitation of resources, human sponsored ecosystems, climatic changes, pollution invasive exotic spices, diseases, shifting cultivation, poaching of wild life etc.
Since the human beings are enjoying all the benefits from biodiversity, they should take proper care for the preservation of biodiversity in all its form and good health for the future generation i.e., the human being should prevent the degradation and destruction of the habitats thereby maintaining the biodiversity at its optimum level.
Conservation of biodiversity is protection, upliftment and scientific management of biodiversity so as to maintain it at its threshold level and derive sustainable benefits for the present and future generation. In other words, conservation of bio-diversity is the proper management of the biosphere by human beings in such a way that it gives maximum benefits for the present generation and also develops its potential so as to meet the needs of the future generations.
Mainly the conservation of biodiversity has three basic objectives:
(a) To maintain essential ecological processes and life supporting systems.
(b) To preserve the diversity of species.
(c) To make sustainable utilisation of species and ecosystems.
Strategies for Conservation of Biodiversity:
The following strategies should be undertaken in order to conserve biodiversity:
(1) All the possible varieties (old or new) of food, forage and timber plants, live stock, agriculture animals and microbes should be conserved.
(2) All the economically important organisms in protected areas should be identified and conserved.
(3) Critical habitats for each species should be identified and safeguarded.
(4) Priority should be given to preserve unique ecosystems.
(5) There should be sustainable utilisation of resources.
(6) International trade in wild life should be highly regulated.
(7) The poaching and hunting of wildlife should be prevented as far as practicable.
(8) Care should be taken for the development of reserves and protected areas.
(9) Efforts should be made to reduce the level of pollutants in the environment.
(10) Public awareness should be created regarding biodiversity and its importance for the living organisms.
(11) Priority should be given in wildlife conservation programme to endangered species over vulnerable species and to vulnerable species over rare species.
(12) The habitats of migratory birds should be protected by bilateral and multilateral agreement.
(13) The over exploitation of useful products of wild life should be prevented.
(14) The useful animals, plants and their wild relatives should be protected both in their natural habitat (in-situ) and in zoological botanical gardens (ex-situ)
(15) Efforts should be made for setting up of National parks and wild life sanctuaries to safeguard the genetic diversity and their continuing evolution.
(16) Environmental laws should be strictly followed.
There are two types of conservation methods namely in-situ and ex-situ conservations. Let us discuss the different conservation methods along with their importance.
(a) In situ conservation:
The conservation of species in their natural habitat or natural ecosystem is known as in situ conservation. In the process, the natural surrounding or ecosystem is protected and maintained so that all the constituent species (known or unknown) are conserved and benefited. The factors which are detrimental to the existence of species concerned are eliminated by suitable mechanism.
The different advantages of in situ conservation are as follows:
(a) If is a cheap and convenient way of conserving biological diversity.
(b) It offers a way to preserve a large number of organisms simultaneously, known or unknown to us.
(c) The existence in natural ecosystem provides opportunity to the living organisms to adjust to differed’ environmental conditions and to evolve in to a better life form.
The only disadvantage of in situ conservation is that it requires large space of earth which is often difficult because of growing demand for space. The protection and management of biodiversity through in situ conservation involve certain specific areas known as protected areas which include national parks, Sanctuaries and Biosphere reserves.
1. Protected areas:
The protected areas are biogeographical areas where biological diversity along with natural and cultural resources are protected, maintained and managed through legal and administrative measures. The demarcation of biodiversity in each area is determined on the basis of climatic and physiological conditions.
In these areas, hunting, firewood collection, timber harvesting etc. are prohibited so that the wild plants and animals can grow and multiply freely without any hindrance. Some protected areas are: Cold desert (Ladakh and Spiti), Hot desert (Thar), Saline Swampy area (Sunderban and Rann of Kutch), Tropical moist deciduous forest (Western Ghats and north East) etc. Protected areas include national parks, sanctuaries and biosphere reserves. There are 37,000 protected areas throughout the world. As per World Conservation Monitoring Centre, India has 581 protected areas, national parks and sanctuaries.
2. National parks:
These are the small reserves meant for the protection of wild life and their natural habitats. These are maintained by government. The area of national parks ranges between 0.04 to 3162 km. The boundaries are well demarcated and circumscribed. The activities like grazing forestry, cultivation and habitat manipulation are not permitted in these areas. There are about 89 national parks in India.
Some important national Parks of India are:
(i) Biological Park, Nandankanan, Orissa,
(ii) Corbett national Park Nainital, U.P. (First national Park)
(iii) Koziranga national Park, Jorhat, Assam
(iv) Tudula national Park, Maharashtra
(v) Hazaribagh national Park, Hazaribagh, Bihar
(vi) Band havgarh national park, M.P.
(vii) Bandipur national park, Karnataka.
(viii) Kanha National Park, M.P.
(ix) Reibul Lamjao National Park, Manipur
(x) Nawgaon National Park, Maharashtra
These are the areas where only wild animals (fauna) are present. The activities like harvesting of timbers, collection of forest products, cultivation of lands etc. are permitted as long as these do not interfere with the project. That is, controlled biotic interference is permitted in sanctuaries, which allows visiting of tourists for recreation. The area under a sanctuary remains in between 0.61 to 7818 km.
Some important sanctuaries of Orissa are as follows:
(i) Nandankanan Zoological Park
(ii) Chandaka Elephant reserve
(iii) Simlipal Tiger Reserve
(iv) Bhitarkanika Wild life Sanctuary
(v) Gharial project at Tikarpada
(vi) Chilika (Nalaban) Sanctuary
4. Biosphere reserves:
Biosphere reserves or natural reserves are multipurpose protected areas with boundaries circumscribed by legislation. The main aim of biosphere reserve is to preserve genetic diversity in representative ecosystems by protecting wild animals, traditional life style of inhabitant and domesticated plant/ animal genetic resources. These are scientifically managed allowing only the tourists to visit.
Some importance of biosphere reserves are as follows:
(a) These help in the restoration of degraded ecosystem.
(b) The main role of these reserves is to preserve genetic resources, species, ecosystems, and habitats without disturbing the habitants.
(c) These maintain cultural, social and ecologically sustainable economic developments.
(d) These support education and research in various ecological aspects,
Some important biosphere reserves are:
Simlipal, (Orissa), Sunderban (West Bengal), Kanha (M.P Kaziranga (Assam) etc. The biosphere reserve net work was introduced by UNESCO 1971.
(b) Ex-situ conservation:
Ex-situ conservation involves maintenance and breeding of endangered plants and animals under partially or wholly controlled conditions in specific areas like zoo, gardens, nurseries etc. That is, the conservation of selected plants and animals in selected areas outside their natural habitat is known as ex-situ conservation.
The stresses on living organisms due to competition for food, water, space etc. can be avoided by ex-situ conservation there by providing conditions necessary for a secure life and breeding.
Some important areas under these conservation are:
(i) Seed gene bank,
(ii) Field gene bank;
(iii) Botanical gardens;
The strategies for ex-situ conservations are:
(i) Identification of species to be conserved.
(ii) Adoption of Different ex-situ methods of conservation.
(i) Long-term captive breeding and propagation for the species which have lost their habitats permanently.
(ii) Short-term propagation and release of the animals in their natural habitat
(iii) Animal translocation
(iv) Animal reintroduction
(v) Advanced technology in the service of endangered species.
The different advantages of ex-situ conservation are:
(a) It gives longer life time and breeding activity to animals.
(b) Genetic techniques can be utilised in the process.
(c) Captivity breed species can again be reintroduced in the wild.
Some disadvantages of this method are:
(a) The favourable conditions may not be maintained always.
(b) Mew life forms cannot evolve.
(c) This technique involves only few species.
Hot spots are the areas with high density of biodiversity or mega diversity which are most threatened at present. There are 16 hot spots in world, out of which two are located in India namely North-East Himalayas and Western Ghats.
The hot spots are determined considering four factors:
(i) Degrees of endemism;
(ii) Degree of expectation
(iii) Degrees of threat to habitat due to its degradation and fragmentation and
(iv) Number of Species diversity.
The global hot spot and endemic species present within them are:
(1) North East Himalayas (3,500);
(ii) Western Ghats (1,600);
(iii) Cape region of South Africa (6,000);
(iv) Upland Western Amazonia (5,000);
(v) Madagascar (4,900);
(vi) Philippines (3,700)
(vii) Boreo (3, 500);
(viii) South West Australia (2,830);
(ix) Western Ecuador (2,500);
(x) Colombian Choco (2,500);
(xi) Peninsular Malaysia) (2, 400);
(xii) Californian Floristic Province (2,140);
(xiii) Central Chile (1,450);
(xiv) Eastern Arc. Mts (Tanzania) (535);
(xv) South West Srilanka (500);
(xvi) South west Tvorie (200).
Different mechanisms involved in the conservation of biodiversity is shown in Fig. 5.1.