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.
Here is an essay on ‘Biodiversity in India’ for class 11 and 12. Find paragraphs, long and short essays on ‘Biodiversity in India’ especially written for school and college students.
Essay on Biodiversity in India
- Essay on the Introduction to Biodiversity in India
- Essay on the Magnitude of Biodiversity
- Essay on the Status of Biodiversity in India
- Essay on the Uses and Threats of Biodiversity
- Essay on the Vanishing Wildlife
- Essay on the Causes of Destruction
Essay # 1. Introduction to Biodiversity in India:
Biodiversity encompasses all species of plants, animals, and microorganisms and the ecosystems and ecological processes of which they are parts. It is an umbrella term for the degree of nature’s variety including both the number and frequency of ecosystems, species or genes in a given assemblage. Thus, the term ‘biodiversity’ refers to the totality of ‘genes, species and ecosystems’ of a region.
It is usually considered at three different levels:
(i) Genetic diversity,
(ii) Species diversity, and
(iii) Ecosystem diversity.
(i) Genetic diversity is the sum total of genetic information, contained in the genes of individuals of plants, animals and microorganisms that inhabit the earth.
(ii) Species diversity refers to the variety of living organisms on earth and has been variously estimated to be between 5 and 50 million or more, though only about 1.4 million have actually been described.
(iii) Ecosystem diversity refers to the variety of habitats, biotic communities, and the ecological processes in the biosphere as well as the tremendous diversity within ecosystems in terms of habitat differences and the variety of ecological processes.
Biodiversity is defined as “the variability among living organisms from all sources, including 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.”
Conservation and sustainable use of biodiversity is fundamental to ecologically sustainable development. Biodiversity is part of our daily lives and livelihood, and constitutes resources upon which families, communities, nations and future generations depend.
Every country has the responsibility to conserve, restore and sustainably use the biological diversity within its jurisdiction. Biological diversity is fundamental to the fulfilment of human needs. An environment rich in biological diversity offers the broadest array of options for sustainable economic ability, for sustaining human welfare and for adapting to change. Loss of biodiversity has serious economic and social costs for any country.
The experience of the past few decades has shown that as industrialisation and economic development in the classical sense have taken place, patterns of consumption, production and needs change, straining, altering and even destroying ecosystems.
India, a megabiodiversity country while following the path of development, has been sensitive to the needs of conservation and, hence, is rich in biological resources. Ethos of conservation and harmonious living with nature is very much ingrained in the lifestyles of India’s people.
Essay # 2. Magnitude of Biodiversity:
The foundation for assessing the importance of biodiversity is an inventory of how many species exist and which species exist where. At the global level the plants and animals are relatively well known. Erwin (1982), for example, suggests as many as 30 million species in total, with most undescribed species living in tropical forests. The known and described number of species of all organisms on the earth is between 1.7 and 1.8 million which is fewer than 15 per cent of the actual number.
About 61 per cent of the known species are insects. Only 4,650 species of mammals are known to biological science. A large number of plant species (2,70,000) and vertebrates are known. But the fact remains that basic knowledge of the organisms that make up most ecosystems, especially in the tropics, is inadequate. Information about bacteria, viruses, protists and Archaea is only fragmentary. For convenience, many assume that about 10 million species exist though the final figure is likely to be 30-50 millions.
Essay # 3. Status of Biodiversity in India:
India occupies only about 2.4 per cent of the world’s land area but its contribution to the world’s biodiversity is approximately 8 per cent of the total number of species which is estimated to be 1.75 million. Of these, 126,188 have been described in India. The species recorded includes flowering plants (angiosperms), mammals, birds, reptiles, amphibians and fishes, constituting 17.3 per cent of the total, whereas nearly 60 per cent of India’s bio wealth is contributed by fungi and insects. Based on the available data, India ranks tenth in the world and fourth in Asia in plant diversity, and ranks tenth in the number of endemic species of higher vertebrates in the world.
There are about 410 species of mammals (8.86% species of the world), about 1,250 species of birds (about 12% of the world species), about 2,546 species of fishes (about 11% of the world species), about 197 species of amphibians (4.4% of the world species), and more than 408 species of reptiles (6% of the world species) are found in India. Among these groups the highest levels of endemism are found in amphibians.
Essay # 4. Uses and Threats of Biodiversity:
Uses of Biodiversity:
Humans derive many direct and indirect benefits from biological diversity. All our food comes from wild species brought into domestication. Most of our medicines, pharmaceuticals, fibres, rubber and timber come from biological resources. The biodiversity also provides many ecological services free of charge that are responsible for maintaining ecosystems. Our water is supplied by one of nature’s most important processes, called the ‘hydrological cycle’. Forested watersheds provide clear, high-quality water for domestic or agricultural use, while healthy rivers provide water, transport and fish.
Threats to Biodiversity:
Major biodiversity threats are as follows:
1. Habitat destruction and fragmentation;
2. Extension of agriculture;
3. Filling up of wetlands;
4. Conversion of rich biodiversity site for human settlement and industrial development;
5. Destruction of coastal areas;
6. Uncontrolled commercial exploitation;
7. Disturbance and pollution; and
8. Introduction of non-native (exotic) species.
Essay # 5. Vanishing Wildlife:
Before the arrival of man about two million years ago, animal species were subjected to natural causes of extinction. A few examples are of extinct ammonites, large cephalopods and brachiopods of Devonian period and dinosaurs of Mesozoic Era. Siwaliks (Himalayan range) were formed in the last and in it are found the largest number of fossils of Tertiary period.
Siwalik fossils include mastodons, hippopotamus, rhinoceros, Sivatherium (large four-horned ruminant), giraffe, horses, camels, bison, deer, antelope, pigs, chimpanzees, orangutans, baboons, langurs, macaques, cheetals, sabre-toothed cats, lions, tigers, sloth bear, Aurochs, leopards, wolves, sholes, porcupines, rabbits, etc.
Many fossil tree species have also been found in the intertrappean beds including Grewioxylon (Eocene) and Heritieroxylon keralensis (middle Miocene) from Kerala and H. arunachalensis (Mio-Pliocene) from Arunachal Pradesh. Grossopteris (fern fossil) was discovered from India and Antarctica led to the discovery of Gondwanaland. Fossil cycads are also found in India.
From Narmada valley was discovered the first dinosaur, Titanosaurus indicus. Another dinosaur fossil from the same area was Rajasaurus narmadensis. Whale fossil Himalayacetus subathuensis was found in Simla hills (Eocene). This area was under water during Tertiary period. Another whale fossil was Remingtonocetus about 43-46 million years old.
During Indus valley civilisation species of wild cattle Bos primegenius nomadicus was vanished. Other mammals which became extinct in India are Indian/Asiatic cheetah, Javan Rhinoceros and Sumatran rhinoceros.
Pink-headed duck (Rhodonessa caryophyllacea) and Himalayan Quail (Ophrysia superciliosa) have became extinct.
The number of species of wild fauna disappeared during the last four centuries are 7 species, 11 species, 27 species and 67 species in seventeenth, eighteenth, nineteenth and twentieth centuries respectively.
Essay # 6. Causes of Destruction:
It is very necessary to access the factors which are hampering in the growth of population of the species such as decimating (death) factors like diseases, predators, etc., or scarcity of food, water and shelter.
Man can easily destroy but cannot create a new species. Forests are unlocked property, it is vast and open and, hence, vulnerable for theft, hunting and killing, poaching, etc. Enormous growth in human population results in conversion of forest into agricultural fields, hunting of wild animals for food, etc. Increase in human population and enhancement in cattle (livestock population) goes side by side which causes adverse effect on wild population.
Pollutants as insecticides, byproducts of industries in the form of gases and water pollutants, quarry of mines, etc., inside forest and such other activities resulting into habitat shrinkage as well as death and disease among the wild animals. Hunting, poaching, killing, smuggling, etc., of wild animals have been hampering and suffering the wild animals. Majority of people are poor and illiterate and are unaware about the importance of wildlife and its role in ecosystem. Wildlife is very much essential for ecobalance and is ultimately essential for human life.
For the existence of an organism/wildlife, food, water and shelter are required. These basic components are exclusively related with wildlife habitats. Wildlife habitats are presently undergoing tremendous changes primarily by the man for his needs, encroachment of forest land for grazing and agricultural purposes due to mushroom growth in human population, constructing roads and cities, etc.
Therefore, man’s manipulation of environment for his needs is the most prevalent factor affecting wildlife habitat and wildlife populations. For instance, in U.S.A., the dense old growth forests may be disastrous to the spotted owl’s nesting and feeding requirements, while it greatly increases preferred forage food for elk.
Destruction of Habitat:
The most serious depletion of wildlife is due to habitat destruction. Habitats which protect wildlife are being converted for human settlements, harbours, dams, reservoirs, croplands, grazing grounds, mining operations, etc. Environmental pollution and deforestation have also caused the degradation of important habitats.
Migratory animals are also vulnerable to the destruction of habitats because disturbance at any point of their migratory routes affects them. Some of the dams are blocking spawning, migration of fishes by inundating habitats and by altering the physical environment. Many species of whales, sea cows and sea turtles are facing total extinction as they are caught by mechanical devices for the sea industry.
Vultures and kites feed on carcases. Since carcases are being buried or burnt now, the population of large flying bird, California condor (Gymnogyps californianus) has started declining.
Asiatic wild ass (Asinus hemionus khur) in Rann of Kutch, Indian lion, musk deer, etc., are facing danger of imminent extinction due to reduction of habitat.
In wild animals, there are a number of diseases which are decimating factors and cause a lot of loss of wild animals. It is also very difficult to diagnose and treat the disease in wild animals because they are free ranging animals. Khera (1980) pointed out that the prevalence of epizootic diseases among wildlife has also been a major factor associated with decline in number of some species of wildlife population.
Important diseases found in wild animals are as follows:
1. Foot and Mouth disease (FMD) caused by Picorna virus mostly occurring in wild boar, cheetal, sambhar and gaur (hoofed mammals).
2. Rinderpest caused by Paramyxo virus found in ruminants such as cattle, cheetal, sambhar, gaur and wild buffalo, etc. It also infects wild animals through the cattle.
3. Anthrax caused by Bacillus anthrasis (bacteria) found in mammals (enlargement of spleen).
4. Brucellosis caused by Brucella bacteria found in cattle, cheetal, sambhar, etc. It causes tumor in the joints.
5. Botulism a kind of paralysis caused by Clostridium botulinum (bacteria). It makes the food poisonous. It occurs in aquatic birds.
6. Tuberculosis caused by Bacterium tuberculosis. It is found in wild animals like human beings. It is also common in monkeys.
7. Rabies caused by Rhabdo virus. It is very common in pet dogs and street dogs, wolf, jackal, fox, jungle cat, mongoose, etc.
8. Distemper caused by Paramyxo virus. It is found in carnivorous mammals. Fever affects central nervous system.
Adverse climatic conditions also cause casualty in wild animals such as very hot weather, excessive rainfall and cold, flood, earthquake, volcano, etc. The population having excessive number than the carrying-capacity is more liable to death. Such deaths can be minimised by increasing carrying capacity, food, water and shelter.
Fire, flood, earthquake and road crossing, etc., also cause their accidental death. In forest fire, many wild animals, their young ones, eggs, shelter are burnt. Such accidents can be avoided or minimised by proper management.
Wild animals are also killed by poisoning by man to save agricultural crops and cattle, etc.
Illegal hunting of wild animals by man is also to be checked. It is done by smugglers and local people living inside forest or neighbouring forest. It causes heavy loss in wild populations.