This MCQ module is based on: Conservation, Hotspots, Red List & End-of-Book Exercises
TOPIC 29 OF 29
Conservation, Hotspots, Red List & End-of-Book Exercises
🎓 Class 11
Social Science
CBSE
Theory
Ch 14 — Biodiversity and Conservation
⏱ ~30 min
🌐 Language: [gtranslate]
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14.8 Loss of Biodiversity — Why Species Are Vanishing
In the first half of this chapter we learnt what biodiversity is and why it matters. Now we turn to the harder side of the story. Since the last few decades, the rapid growth in human population has increased the rate of consumption of natural resources, and this has accelerated the loss of species and habitats in different parts of the world. Tropical regions, which occupy only about one-fourth of the total area of the world, contain about three-fourths of the world's human population. Over-exploitation of resources and large-scale deforestation have become rampant to feed the needs of this large population. Because tropical rain forests contain about 50 per cent of the species on the earth, the destruction of natural habitats here has proved disastrous for the entire biosphere.
⚠️ NCERT Snapshot — The Causes of Biodiversity Loss
- Natural calamities — earthquakes, floods, volcanic eruptions, forest fires and droughts damage flora and fauna and change the biodiversity of affected regions.
- Pollutants — pesticides, hydrocarbons and toxic heavy metals destroy weak and sensitive species.
- Exotic species? — species not native to a habitat but introduced from outside; they can damage natural communities, sometimes catastrophically.
- Poaching and over-exploitation — tigers, elephants, rhinoceros, crocodiles, minks and many birds have been hunted mercilessly by poachers for horn, tusks and hides, pushing them into the endangered category.
- Habitat destruction and fragmentation — clearing forests for agriculture, mining and settlement breaks ecosystems into small pieces too small for wide-ranging species.
- Climate change — shifting rainfall, rising temperatures and acidifying oceans add a new and global stress on top of all the local ones.
Five Big Drivers of Loss — A Closer Look
Habitat Destruction & Fragmentation
Forests cleared for agriculture, dams, roads, mines and cities. Remaining patches are too small for tigers, elephants and migratory birds.
Over-exploitation & Poaching
Hunting for horn, tusks, hides; over-fishing; unsustainable harvesting of medicinal plants. Drives commercially valuable species to the edge.
Pollution
Pesticides, industrial effluents, plastic, oil spills, heavy metals and noise. The weakest species die first; food chains accumulate the poison.
Invasive (Exotic) Species
Water hyacinth, lantana, parthenium and African catfish out-compete native species in their new homes.
Climate Change
Shifting temperature and rainfall belts, ocean warming and acidification, glacier loss; species cannot migrate fast enough.
Natural Calamities
Earthquakes, floods, volcanic eruptions, droughts and forest fires alter local biodiversity though usually allow recovery.
Agricultural Simplification
Replacement of mixed traditional crops with one or two hybrids — collapses agro-biodiversity.
Population Pressure
Three-fourths of humanity in the species-richest tropical zones — the engine behind all of the above.
Background Extinction vs Mass Extinction
Species have always come and gone. The slow, steady disappearance of one species roughly every million years is called the background rate of extinction. But geologists also see five spectacular mass extinction events? in the rock record — short pulses (each lasting perhaps a few hundred thousand years) when 50 to 90 per cent of all species disappeared together. The most famous is the end-Cretaceous event, 66 million years ago, when a giant asteroid impact wiped out the non-avian dinosaurs. Today, scientists worry that we are entering a sixth mass extinction — but this one is being driven not by an asteroid or a volcanic catastrophe, but by us.
Five Past Mass Extinctions and Today's Crisis (% of species lost)
📜 Quote — NCERT
"The number of species globally vary from 2 million to 100 million, with 10 million being the best estimate." Yet the current rate of extinction caused by human activity is estimated to be 100 to 1,000 times the natural background rate — a quiet, planet-wide emergency.
THINK ABOUT IT — Are All Exotic Species "Bad"?
L4 Analyse
Many of our most-loved Indian foods — potato, tomato, chilli, maize, coffee — are exotic species, brought from elsewhere. Yet some exotic species, such as water hyacinth or lantana, have devastated native ecosystems. What distinguishes a "useful exotic" from an "invasive exotic"? Discuss.
The key difference is whether the introduced species can escape human control and spread on its own. Crops like potato, tomato and maize remain confined to the fields where farmers plant them; they cannot survive without human care, so they enrich human diets without displacing wild species. Lantana, water hyacinth, parthenium and the African catfish, in contrast, escape into the wild, find no natural predators or diseases in their new environment, and reproduce explosively — choking lakes, replacing native shrubs and out-competing native fish. They become invasive. The technical rule of thumb in conservation biology is the "10 per cent rule": about 10 per cent of introduced species establish wild populations, and about 10 per cent of those become invasive — that is, roughly 1 in 100. Useful exotics are domesticated; invasive exotics are wild escapees. Modern biosecurity rules therefore screen new introductions carefully before allowing them in.
14.9 The IUCN Red List — How Threatened Is Threatened?
The International Union for Conservation of Nature and Natural Resources (IUCN) has classified threatened species of plants and animals into categories for the purpose of conservation. The list of names and statuses they publish is internationally famous as the Red List? of threatened species. NCERT focuses on three categories that are most important for school study.
IUCN Red List Categories — A Pyramid of Risk
(i) Endangered Species
Endangered species are those species which are in danger of extinction. The IUCN publishes information about endangered species worldwide as the Red List of threatened species. Indian examples include the Bengal Tiger, Asiatic Lion, One-horned Rhinoceros, Lion-tailed Macaque, Snow Leopard, Great Indian Bustard, Hangul deer and the Red Panda (NCERT Figure 14.2).
(ii) Vulnerable Species
Vulnerable species are those species which are likely to be in danger of extinction in the near future if the factors threatening them continue to operate. The survival of these species is not assured because their populations have already reduced greatly. Examples in India include the Sloth Bear, Indian Wild Dog (dhole) and several species of marine turtles.
(iii) Rare Species
Rare species are those whose populations are very small in the world. They may be confined to a limited area or scattered thinly over a wider area. Their small numbers make them especially vulnerable to chance events such as a single disease outbreak or a single cyclone. The Humboldtia decurrens Bedd (NCERT Figure 14.3) — a rare endemic tree of the Southern Western Ghats — is a classic example.
| Category | Definition | Indian example |
|---|---|---|
| Endangered | In immediate danger of extinction. | Red Panda, Asiatic Lion, Great Indian Bustard |
| Vulnerable | Likely to become endangered in near future if threats continue. | Sloth Bear, Indian Wild Dog |
| Rare | Very small populations, often endemic to a small area. | Humboldtia decurrens, Nilgiri tahr |
14.10 Hotspots of Biodiversity
To direct scarce conservation funds to the most urgent places on the planet, the British ecologist Norman Myers? proposed in 1988 the concept of biodiversity hotspots. Hotspots are defined according to their vegetation — because plants determine the primary productivity of an ecosystem, and most other life depends on plants. Most, but not all, of the hotspots rely on species-rich ecosystems for food, firewood, cropland and income from timber. The IUCN, working with Conservation International and other partners, formally identifies these areas to concentrate resources on those that are most vulnerable.
📖 Definition — Biodiversity Hotspot
A hotspot is a biogeographic region with two qualifying features:
- (i) Endemism: at least 1,500 species of vascular plants found nowhere else on the earth.
- (ii) Habitat loss: the region must have lost at least 70 per cent of its original primary vegetation.
Some of the World's Biodiversity Hotspots — Schematic World Map
India's Four Biodiversity Hotspots
Of the world's 36 hotspots, four lie wholly or partly in Indian territory — making India one of the most important hotspot countries on the planet.
1. Western Ghats & Sri Lanka
Evergreen and semi-evergreen rainforests along the western coast; lion-tailed macaque, Nilgiri tahr, hundreds of endemic frogs.
2. Himalaya
From foothills to the Tibetan plateau; snow leopard, red panda, Hangul deer, thousands of endemic plants.
3. Indo-Burma
North-east India, Myanmar, Indo-China; clouded leopard, hoolock gibbon, Sangai deer of Loktak.
4. Sundaland
Including the Nicobar group of islands; Nicobar megapode, leatherback turtle, dipterocarp rainforests.
🌎 Hotspots Beyond India — A Global View
Other famous hotspots include Mesoamerica, the Caribbean, the Atlantic Forest of Brazil, the Tropical Andes, the Cape Floristic Region of South Africa, Madagascar, the Mediterranean Basin and Southwest Australia. In Madagascar, for example, about 85 per cent of the plants and animals are found nowhere else in the world; in Hawaii many unique plants and animals are threatened by introduced species and land development.
14.11 Conservation of Biodiversity — The Indian and Global Effort
Biodiversity is essential for human existence. All forms of life are so closely interlinked that disturbance in one part of the web gives rise to imbalance in others. If species of plants and animals become endangered, they cause degradation in the environment, which may threaten human existence itself. There is therefore an urgent need to educate people to adopt environment-friendly practices and to reorient our development so that it is harmonious with other life forms and is sustainable. There is increasing consciousness that such conservation, with sustainable use, is possible only with the involvement and cooperation of local communities and individuals. The development of institutional structures at local levels is necessary. The critical problem is not merely the conservation of species or of the habitat, but the continuation of the process of conservation itself.
The World Conservation Strategy — Six Steps
The Government of India, along with 155 other nations, signed the Convention on Biological Diversity at the Earth Summit held at Rio de Janeiro, Brazil in June 1992. The world conservation strategy has suggested the following steps for biodiversity conservation:
| # | Action |
|---|---|
| (i) | Efforts should be made to preserve the species that are endangered. |
| (ii) | Prevention of extinction requires proper planning and management. |
| (iii) | Varieties of food crops, forage plants, timber trees, livestock animals and their wild relatives should be preserved. |
| (iv) | Each country should identify habitats of wild relatives and ensure their protection. |
| (v) | Habitats where species feed, breed, rest and nurse their young should be safeguarded and protected. |
| (vi) | International trade in wild plants and animals should be regulated. |
India's Wild Life (Protection) Act, 1972
To protect, preserve and propagate the variety of species within natural boundaries, the Government of India passed the Wild Life (Protection) Act, 1972. Under this Act, National Parks and Sanctuaries were established and Biosphere Reserves were declared. (Details of these biosphere reserves are given in the companion NCERT volume India: Physical Environment.)
14.12 Two Faces of Conservation — In-situ & Ex-situ
Modern conservation works on two complementary fronts: protecting species where they live (in-situ) and protecting them off-site in zoos, gardens and gene banks (ex-situ). Both are necessary; neither alone is enough.
In-situ vs Ex-situ Conservation — A Tree
(A) In-situ Conservation
In-situ conservation? means protecting species in their natural habitats — the ecosystems where they have evolved and where they continue to play their ecological role. India uses four main legal categories:
- National Parks — strictly protected areas where no human activity is allowed except authorised research and tourism. India has more than 100 of them — Jim Corbett, Kanha, Kaziranga, Bandipur, Hemis, Ranthambore, Gir.
- Wildlife Sanctuaries — somewhat less strict; certain regulated activities (grazing, collection of minor produce) may be permitted. India has more than 500.
- Biosphere Reserves? — large multi-purpose reserves that combine a strictly protected core with buffer and transition zones for sustainable human use. India has 18 biosphere reserves, including Nilgiri, Nanda Devi, Sundarban and the Gulf of Mannar.
- Sacred Groves? — small forest patches protected by local communities for religious and cultural reasons; these are India's oldest and most decentralised form of conservation, found in Meghalaya, Maharashtra, Karnataka, Rajasthan and elsewhere.
(B) Ex-situ Conservation
Ex-situ conservation? means protecting species outside their natural habitats. It complements in-situ work by acting as an insurance policy: if the wild population is wiped out, captive populations can repopulate the original habitat.
- Botanical Gardens — collections of living plants, with seed banks attached (e.g., the Indian Botanical Garden at Howrah).
- Zoos and Aquaria — captive breeding programmes for endangered animals (e.g., the Hyderabad Zoo's Asiatic Lion programme).
- Gene Banks? and Seed Banks — refrigerated storage of seeds, sperm, eggs and tissue (e.g., the National Bureau of Plant Genetic Resources, New Delhi).
- Cryopreservation — storing biological material at temperatures around –196 °C in liquid nitrogen, where biological time effectively stops.
🌐 Mega-diversity Centres & Hotspots — A Useful Distinction
Mega-diversity centres are countries that hold most of the world's species — Mexico, Colombia, Ecuador, Peru, Brazil, Democratic Republic of Congo, Madagascar, China, India, Malaysia, Indonesia and Australia. Hotspots are biogeographic regions (often crossing national borders) that combine high endemism with serious habitat loss. India is both a mega-diversity country and the home of four hotspots.
14.13 International Treaties — How the World Cooperates
Biodiversity does not respect national borders, and so its conservation has to be international. Three major treaties form the backbone of the global system.
| Treaty | Year | Purpose |
|---|---|---|
| CITES? — Convention on International Trade in Endangered Species | 1973 (Washington) | Regulates international trade in wild plants and animals to ensure that trade does not threaten species' survival. |
| Convention on Biological Diversity (CBD) — Earth Summit | 1992 (Rio de Janeiro) | The flagship global agreement for conservation and sustainable use of biodiversity, signed by India and 155 other nations. |
| Cartagena Protocol on Biosafety (under the CBD) | 2000 | Regulates the safe handling and transboundary movement of "Living Modified Organisms" (genetically modified organisms) so as to protect biodiversity. |
Together, CITES governs trade, the CBD governs conservation policy, and the Cartagena Protocol governs biotechnology. India has implemented all three through domestic legislation — most importantly the Wild Life (Protection) Act, 1972 and the Biological Diversity Act, 2002.
MAP SKILL — Locate India's Four Hotspots
L3 Apply
On a blank outline map of India, mark and label the four biodiversity hotspots that overlap with Indian territory. Use a different shading for each. Then, in a small text box beside each, name one endemic species characteristic of that hotspot.
(1) Western Ghats & Sri Lanka — narrow coastal strip from Gujarat to Kerala and Tamil Nadu; iconic species: lion-tailed macaque (also Nilgiri tahr, Malabar civet). (2) Himalaya — entire arc from Jammu & Kashmir through Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh; iconic species: snow leopard (also red panda, Hangul deer). (3) Indo-Burma — north-eastern states (Manipur, Mizoram, Nagaland, Tripura, parts of Meghalaya and Assam) extending into Myanmar; iconic species: hoolock gibbon (also Sangai deer of Loktak Lake, clouded leopard). (4) Sundaland — Nicobar group of islands; iconic species: Nicobar megapode (also leatherback turtle, Nicobar long-tailed macaque). The hotspots together overlap roughly 16 per cent of Indian territory but contain a disproportionate share of national biodiversity.
14.14 Mega-diversity Countries
There are some countries which are situated in the tropical region and possess a large number of the world's species diversity. They are called mega-diversity centres. As noted earlier, twelve such countries are recognised — Mexico, Colombia, Ecuador, Peru, Brazil, Democratic Republic of Congo, Madagascar, China, India, Malaysia, Indonesia and Australia. In order to concentrate resources on those areas that are most vulnerable, the IUCN has identified specific regions inside and across these countries as biodiversity hotspots.
📑 Assertion–Reason Questions (Choose A / B / C / D)
Code: (A) Both A and R are true and R is the correct explanation of A. (B) Both A and R are true but R is NOT the correct explanation of A. (C) A is true but R is false. (D) A is false but R is true.
Assertion (A): A region must satisfy two criteria to be called a biodiversity hotspot.
Reason (R): A hotspot must contain at least 1,500 endemic species of vascular plants AND must have lost at least 70 per cent of its original primary vegetation.
Answer: (A) — Both true and R is exactly the explanation. The two-criterion definition was proposed by Norman Myers in 1988 and remains the standard. India's four hotspots all meet both tests.
Assertion (A): Tropical rain forests are the most important ecosystems for biodiversity conservation.
Reason (R): Tropical rain forests cover only one-fourth of the world's land area but contain about 50 per cent of all species on the earth.
Answer: (A) — Both statements are true and R correctly explains A. NCERT states: "tropical rain forests contain 50 per cent of the species on the earth." Hence their destruction has disastrous global consequences.
Assertion (A): In-situ and ex-situ conservation are complementary rather than substitute strategies.
Reason (R): In-situ conservation protects species in their natural ecosystems, while ex-situ conservation acts as an insurance reserve in zoos, botanical gardens and gene banks against the failure of in-situ populations.
Answer: (A) — Both statements are true and R is the correct explanation. Ex-situ collections cannot replace the ecological role of a wild population, but they do preserve the genetic material so that wild populations can be restored if lost.
🧠 Competency-Based Questions — Apply, Analyse, Evaluate, Create
Scenario: The Ministry of Environment plans a new highway through a corridor of forest in the Western Ghats. The proposed route will cut a 45-km strip through habitat of the lion-tailed macaque (endangered, endemic), pass within 5 km of a Tiger Reserve, and bisect a sacred grove protected by the local community for over 300 years. An environmental impact study has been ordered. You are part of the assessment team.
1. Identify the four major drivers of biodiversity loss that this project would activate, with one specific consequence of each.
L3 ApplyAnswer: (i) Habitat destruction and fragmentation — a 45-km strip splits the macaque's home range into two smaller populations that cannot interbreed, raising local extinction risk. (ii) Pollution — vehicle exhaust, run-off oils and noise will reach the Tiger Reserve buffer 5 km away, weakening sensitive species. (iii) Over-exploitation / poaching — new roads dramatically increase poacher access; tigers and pangolins are most at risk. (iv) Cultural and ethical loss — bisecting the sacred grove destroys an irreplaceable community institution and the local in-situ conservation it has provided.
2. Explain why the Western Ghats are classified as a biodiversity hotspot. Use the two formal criteria.
L4 AnalyseAnswer: The Western Ghats & Sri Lanka hotspot satisfies both Myers criteria. Endemism — well over 1,500 endemic vascular plant species are recorded from the region, including hundreds of endemic frogs (the Nasikabatrachus "purple frog"), the lion-tailed macaque, the Nilgiri tahr, the Nilgiri langur, several endemic Humboldtia trees and many endemic orchids; over a third of all Western Ghats species are endemic. Habitat loss — original primary forest cover has shrunk by far more than 70 per cent due to plantations (tea, coffee, rubber), hydro-projects, mining, urbanisation and roads; very little untouched evergreen forest now survives outside protected areas. Both criteria are exceeded, and the IUCN therefore lists Western Ghats & Sri Lanka as one of the world's 36 hotspots.
3. Evaluate three alternatives — (a) build the highway as planned, (b) reroute around the forest at higher cost, (c) replace highway with rail and add wildlife overpasses.
L5 EvaluateAnswer: Option (a), the original alignment, fails the basic ethical test of in-situ conservation under the Wild Life (Protection) Act and CBD obligations — it removes habitat from an endangered, endemic primate and damages a sacred grove. Option (b), a rerouted alignment, increases construction cost by perhaps 20–40 per cent but preserves nearly the entire ecosystem; it is the standard recommendation under the Environmental Impact Assessment framework. Option (c), a railway with elevated wildlife crossings or canopy bridges, has the highest capital cost but the lowest long-term ecological footprint — railways pollute less per passenger-km, fragment less if elevated, and discourage poaching access. On the criteria of biodiversity preservation, intergenerational equity, treaty obligations (CBD, CITES) and sustainable development, option (c) is best, option (b) is acceptable, option (a) should be rejected.
4. Design a five-point management plan that combines in-situ and ex-situ measures to protect the lion-tailed macaque population. (HOT)
L6 CreateSample plan: (1) In-situ — Habitat protection: extend the existing sanctuary boundary to include the corridor; ban new commercial activity inside the 5-km buffer. (2) In-situ — Habitat connectivity: build canopy bridges across any unavoidable road segments; afforest gaps with native rain-forest tree species to reconnect fragments. (3) In-situ — Community partnership: formally recognise the sacred grove as a Biodiversity Heritage Site under the Biological Diversity Act, 2002, with annual conservation grants to the village panchayat. (4) Ex-situ — Captive breeding: maintain a coordinated captive population of about 50 individuals across two zoos (Mysuru and Bannerghatta) under a managed studbook, with periodic exchanges to maintain genetic diversity. (5) Ex-situ — Gene bank: store sperm, ovum and DNA samples in liquid nitrogen at the National Bureau of Animal Genetic Resources as ultimate insurance. The plan also includes annual monitoring, reporting under the CBD, and a research partnership with universities to track population trends.
14.15 NCERT Exercises — Full Model Answers
1. Multiple Choice Questions
(i) Conservation of biodiversity is important for :
(a) Animals (b) Animals and plants (c) Plants (d) All organisms Correct: (d)
Biodiversity covers plants, animals, fungi, micro-organisms and human cultural heritage that depends on them — every form of life is interlinked.
(ii) Threatened species are those which :
(a) threaten others (b) Lion and tiger (c) are abundant in number (d) are suffering from the danger of extinction Correct: (d)
"Threatened" is the IUCN umbrella term covering Endangered, Vulnerable and Rare species — all of which face some risk of extinction.
(iii) National parks and sanctuaries are established for the purpose of :
(a) Recreation (b) Hunting (c) Pets (d) Conservation Correct: (d)
Although recreation may be a secondary outcome, the legal purpose of these protected areas under the Wild Life (Protection) Act, 1972 is conservation of biodiversity in-situ.
(iv) Biodiversity is richer in :
(a) Tropical Regions (b) Polar Regions (c) Temperate Regions (d) Oceans Correct: (a)
Greater solar energy, abundant water and a long ice-free history make the tropics consistently the richest in species — about 50 per cent of the world's species in 25 per cent of the land.
(v) In which one of the following countries, the 'Earth Summit' was held?
(a) the UK (b) Mexico (c) Brazil (d) China Correct: (c)
The Earth Summit and the resulting Convention on Biological Diversity (CBD) were held at Rio de Janeiro, Brazil in June 1992.
2. Answer the Following Questions in About 30 Words
(i) What is biodiversity?
Biodiversity is the number and variety of organisms found within a specified geographic region — the variability among plants, animals and micro-organisms, the genes they contain and the ecosystems they form.
(ii) What are the different levels of biodiversity?
Biodiversity is recognised at three nested levels: genetic diversity (variation of genes within a species), species diversity (variety of species in an area) and ecosystem diversity (variety of ecosystem types and habitats).
(iii) What do you understand by 'hotspots'?
Hotspots are biogeographic regions exceptionally rich in endemic species (at least 1,500 endemic vascular plants) yet seriously threatened, having lost at least 70 per cent of their original vegetation. There are 36 such hotspots worldwide and four in India.
(iv) Discuss briefly the importance of animals to human kind.
Animals supply food (meat, milk, eggs, fish), clothing (wool, leather, silk), draught power, medicines (antitoxins, hormones), pollination of crops, decomposition of waste and natural pest control. They also enrich human culture spiritually, aesthetically and recreationally.
(v) What do you understand by 'exotic species'?
Exotic species are species that are not natural inhabitants of the local habitat but have been introduced from outside. When they spread aggressively in their new home, they can damage native communities — for example, water hyacinth in Indian lakes.
3. Answer the Following Questions in About 150 Words
(i) What are the roles played by biodiversity in the shaping of nature?
Biodiversity plays at least four interlinked roles in shaping nature. Ecologically, the variety of species capture and store energy, build and decompose organic material, cycle water and nutrients, fix atmospheric gases like nitrogen, regulate the climate and pollinate plants — without these processes, ecosystems would collapse. The greater the diversity, the more stable and productive the ecosystem. Economically, biodiversity supplies food crops, livestock, forests, fisheries and medicinal resources — the entire agro-biodiversity on which human nutrition depends. It is also a reservoir of genetic material for future plant breeding and pharmaceuticals. Scientifically, every species teaches us something about how life evolved and how nature functions; the loss of any one species erases information that science cannot recover. Ethically and culturally, biodiversity has intrinsic worth — every species has the right to exist — and forms an integral part of human cultures through sacred groves, totem animals, festival flowers and the arts. Together these roles mean biodiversity is the very fabric of nature.
(ii) What are the major factors that are responsible for the loss of biodiversity? What steps are needed to prevent them?
The principal factors are habitat destruction and fragmentation (deforestation, dam-building, mining, urbanisation), over-exploitation (poaching of tigers, elephants, rhinos for horn, tusks and hides; over-fishing; unsustainable medicinal-plant collection), pollution (pesticides, hydrocarbons, heavy metals that destroy weak and sensitive species), introduction of exotic species that overwhelm native communities, climate change (shifting temperature and rainfall belts), natural calamities (earthquakes, floods, fires, droughts) and the underlying pressure of human population growth — three-fourths of humanity in the species-richest tropics. To prevent further loss, the World Conservation Strategy recommends six steps: preserve endangered species; plan and manage to prevent extinction; conserve crop varieties, livestock and their wild relatives; identify and protect habitats of wild relatives; safeguard breeding, feeding and resting habitats; and regulate international trade. India's Wild Life (Protection) Act, 1972 establishes National Parks, Wildlife Sanctuaries and Biosphere Reserves; international treaties such as CITES (1973), the CBD (Rio, 1992) and the Cartagena Protocol (2000) coordinate global action; and ex-situ measures such as botanical gardens, zoos, gene banks and seed banks act as biological insurance. The single most important shared step, however, is the involvement and cooperation of local communities in sustainable use.
Project Work — Suggested Solution Outline
Collect the names of national parks, sanctuaries and biosphere reserves of the state where your school is located and show their location on the map of India.
Suggested approach: (1) Visit the website of your State Forest Department or the Wildlife Institute of India to obtain an up-to-date official list. (2) Tabulate them with three columns — Name, Type (NP / WLS / BR), Notable species. (3) On a blank political map of India, mark each protected area with a coloured dot — green for National Parks, yellow for Wildlife Sanctuaries and red for Biosphere Reserves — and label them. (4) Write a short note on the largest one in your state. (5) Add a paragraph on what you, as a citizen of the state, can do to support its conservation effort.
📖 Chapter Summary — At a Glance
- The biosphere is the thin overlap of lithosphere, hydrosphere and atmosphere where life thrives; energy and water are the fundamental drivers of biodiversity.
- Biodiversity = variety of life (Bio + Diversity) — across genes, species and ecosystems. Total ≈ 10 million species; ≈ 1.7 million identified.
- Biodiversity is the result of 2.5–3.5 billion years of evolution. About 50 per cent of all species live in tropical rainforests.
- Three nested levels: genetic, species, ecosystem.
- Roles: ecological (productivity, stability, nutrient cycling), economic (food, medicine, fibre), scientific (clues to evolution), ethical/cultural/aesthetic.
- Causes of loss: habitat destruction, over-exploitation, pollution, exotic species, climate change and population pressure; we are entering a sixth mass extinction.
- IUCN Red List categories — Endangered, Vulnerable and Rare.
- Hotspots (Norman Myers, 1988): two criteria — ≥1,500 endemic vascular plants AND ≥70% habitat loss; 36 globally; 4 in India — Western Ghats & Sri Lanka, Himalaya, Indo-Burma, Sundaland.
- Mega-diversity centres: 12 countries, including India.
- Conservation: in-situ (National Parks, Wildlife Sanctuaries, Biosphere Reserves, Sacred Groves) + ex-situ (botanical gardens, zoos, gene/seed banks, cryopreservation).
- Major treaties: CITES (1973), CBD Rio (1992), Cartagena Protocol (2000); India's law: Wild Life (Protection) Act, 1972.
14.16 Key Terms
Biosphere
The zone of overlap between lithosphere, hydrosphere and atmosphere where life occurs.
Biodiversity
Number and variety of organisms in a region — including genes, species and ecosystems.
Genetic diversity
Variation of genes within a single species; raw material of evolution.
Species diversity
Variety of species in a defined area — measured by richness, abundance, types.
Ecosystem diversity
Diversity of habitat types and ecological processes across a region.
Endemic species
A species naturally restricted to one region — e.g., Nilgiri tahr.
Exotic species
A species introduced from outside its native habitat; sometimes invasive.
Mass extinction
A short geological pulse during which 50–90% of species disappear together.
Hotspot
Region with ≥1,500 endemic plants AND ≥70% habitat loss; 36 worldwide.
In-situ conservation
Protection of species in their natural habitat — parks, sanctuaries, reserves, sacred groves.
Ex-situ conservation
Protection outside natural habitat — botanical gardens, zoos, gene banks, cryopreservation.
Sacred grove
Patch of forest protected by local communities for religious or cultural reasons.
Biosphere reserve
Large multi-purpose protected area with core, buffer and transition zones; 18 in India.
CITES (1973)
Convention on International Trade in Endangered Species — regulates wildlife trade.
CBD (1992 Rio)
Convention on Biological Diversity — global framework signed by India and 155 nations.
Cartagena Protocol (2000)
Treaty under CBD regulating transboundary movement of genetically modified organisms.
IUCN
International Union for Conservation of Nature — publishes the Red List.
Red List
IUCN's worldwide catalogue of threatened species and their categories.
Norman Myers
British ecologist who proposed the hotspot concept in 1988.
Gene bank
Refrigerated repository of seeds, sperm, eggs or tissue for ex-situ conservation.
🎓📘🌿
End of Book — Fundamentals of Physical Geography (Class 11)
Congratulations! You have reached the final chapter of the NCERT textbook Fundamentals of Physical Geography. From the structure of the universe and the interior of the earth, through the moving lithosphere, the running waters and the great atmosphere, you have arrived at last at the thin film of life that crowns it all — the biosphere.
Physical geography is, in the end, the story of how the earth makes itself a home for life. As you close this book, remember that the variety of life you have just studied is also the variety you must help protect — for this is the only planet we have.
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