Biodiversity and Conservation - Class 12 Biology

Class 12 Biology | Unit X — Ecology

Chapter 15: Biodiversity and Conservation

Patterns of Biodiversity • Loss • In Situ & Ex Situ Conservation • Hotspots

1. What is Biodiversity?

Definition: Biodiversity (Biological Diversity) is the variety and variability of life on Earth including the number of species, their genetic variability, and the ecosystems they form. The term was popularised by sociobiologist Edward Wilson.

1.1 Levels of Biodiversity

Genetic Diversity: Variation in the genetic composition within a species. Example: Rauwolfia vomitoria shows variation in potency of the drug reserpine across its range. India has >50,000 genetically distinct strains of rice and over 1,000 varieties of mango.
Species Diversity: Variety of species in a given region. Measured by species richness and evenness. Example: Western Ghats have greater amphibian species diversity than Eastern Ghats.
Ecological (Ecosystem) Diversity: Variety of ecosystems in a given region — deserts, rainforests, wetlands, mangroves, coral reefs, etc. India has a greater ecosystem diversity than a Scandinavian country.

📋 Key Statistic: Earth has ~1.5 million species documented (Robert May estimates ~7 million total). India: >45,000 plant species (13th globally) and >89,000 animal species (~7.4% of world's species). India has only 2.4% of world's land area but 8.1% of global species diversity.

1.2 Biodiversity Patterns — Latitudinal Gradient

Species diversity decreases from equator to poles. Tropics have greatest biodiversity:

Colombia (near equator) has ~1,400 bird species. New York has 105. Greenland has 56.
Amazon rainforest has ~40,000 plant species, 3,000 fish, 1,300 birds.
Tropical forests cover <10% of Earth's surface but contain >50% of all species.

Reasons for greater tropical biodiversity:

Tropics have had a longer evolutionary time (undisturbed by glaciation).
More solar energy available → higher productivity → more niches.
Less seasonal variation → niche specialization.
constant warm temperature promotes higher species diversification.

1.3 Species-Area Relationship

Definition: The observation that larger areas support more species. Formulated by Alexander von Humboldt. The relationship is: log S = log C + Z log A (where S = species richness, A = area, Z = slope, C = Y-intercept).

Value of Z (slope):

For islands / smaller areas: Z = 0.1 to 0.2
For large continental areas: Z = 0.6 to 1.2
Typically Z ≈ 0.1–0.2 for most taxa on continents.

⚠️ NEET Focus (2013, 2016, 2018): Species-area relationship: log S = log C + Z log A. Z value for small islands = 0.1–0.2; for large continents = 0.6–1.2. Formulated by Alexander von Humboldt. Rivet Popper hypothesis = species are like rivets in a plane wing (Paul Ehrlich).

2. Why Should We Conserve Biodiversity?

2.1 Importance of Biodiversity — Three Arguments

Narrowly Utilitarian (Economic Value): Direct economic benefits: food, firewood, fibre, medicines (~25% of modern drugs derived from plants), industrial products. Ecosystem services worth ~US$ 33 trillion/year globally.
Broadly Utilitarian (Ecological Services): Ecosystems provide services: oxygen production, water purification, pollination (bees, birds), pest control, climate regulation, soil formation, nutrient cycling. Amazon forest produces 20% of total oxygen in Earth's atmosphere.
Ethical Argument (Intrinsic Value): Every species has a right to exist regardless of its economic value. We have a moral responsibility to protect biodiversity for future generations. Other species also have the right to coexist with us on this planet.

⚠️ NEET Focus: The three arguments for biodiversity conservation: Narrowly utilitarian (economic use), Broadly utilitarian (ecosystem services), Ethical (intrinsic value). Amazon produces 20% of Earth's oxygen. Ecosystem services estimated at US$ 33 trillion/year.

2.2 Rivet Popper Hypothesis (Paul Ehrlich)

Species in an ecosystem are like rivets on a plane wing. Losing a few rivets doesn't crash the plane — but eventually, losing too many causes catastrophic failure. Each new species loss increases the risk of ecosystem collapse.

3. Loss of Biodiversity

Definition: Biodiversity loss refers to the decline in the number of species or the genetic variety within species. The current rate of extinction is 100–1000 times faster than the natural background rate.

📋 Scale of Loss: Since 1600 AD, over 784 species have gone extinct (IUCN, 2004). Currently, ~15,500 species are threatened with extinction. The Earth may be heading toward its 6th mass extinction (previous 5 were natural; this one is human-caused).

3.1 The Evil Quartet — 4 Major Causes of Biodiversity Loss

Term coined by Jared Diamond.

Habitat Loss and Fragmentation:
- The most important cause of biodiversity loss globally.
- Deforestation in tropical regions (Amazon, Southeast Asia) for agriculture, urbanisation, logging.
- When large habitats are fragmented, smaller pieces can't support many species — especially large-bodied animals with large territory requirements.
- Example: Deforestation of tropical forests — loss of 1-8% plant species for every 10-fold decrease in area.
Over-Exploitation:
- Human greed drives overuse of natural resources beyond sustainable limits.
- Examples: Steller's sea cow (extinct 1768), Passenger pigeon (extinct 1914), Dodo (extinct 1690s — Mauritius), Quagga (extinct 1883).
- Marine fisheries collapse due to overfishing.
Alien Species Invasions:
- Introduction of non-native species into an ecosystem can outcompete, prey upon, or bring disease to native species.
- Examples: Nile perch introduced into Lake Victoria → extinction of >200 native cichlid fish species. Water Hyacinth (Eichhornia crassipes) in India — clogs water bodies. Lantana or Parthenium hysterophorus — invasive weeds in India. African catfish Clarias gariepinus introduced into India.
Co-extinctions:
- When one species goes extinct, species dependent on it (as mutualists, host-parasites, etc.) also go extinct.
- Example: If a plant species becomes extinct, all its specific pollinators, seed dispersers, and specialized herbivores that depend on it also go extinct.
- Example: Coevolved plant-pollinator pairs (orchid-bee mutualism).

⚠️ NEET Focus (2014, 2017, 2019, 2021): Evil Quartet = HOAC: Habitat loss, Over-exploitation, Alien invasions, Co-extinctions. Most important cause = Habitat loss and fragmentation. Nile perch → Lake Victoria cichlids. Dodo — Mauritius. Passenger pigeon — 1914 (last individual: Martha). Water hyacinth = Eichhornia crassipes.

4. Biodiversity Conservation

Definition: Biodiversity conservation is the protection, management, and restoration of biodiversity for sustaining life on Earth and ensuring long-term survival of species, ecosystems, and ecological processes.

4.1 In Situ Conservation (On-site / In Place)

Definition: In situ conservation = protecting species in their natural habitat. The most preferred and effective method of conservation.

Types of Protected Areas in India:

Type	Count (India)	Key Feature
Biosphere Reserves	18	Large protected areas with core zone, buffer zone, transition zone. Also have human settlements. UNESCO Man and Biosphere Programme.
National Parks	106	Strictly protected; no human activity or resource use allowed. Highest protection level.
Wildlife Sanctuaries	567	Restricted human activities allowed; protection of specific species.
Sacred Groves	Thousands	Forest patches protected by tribal communities for religious/cultural reasons.

📋 India's Protected Areas: India has 34 Biodiversity Hotspots (globally, 34 hotspots globally cover <2% of land but harbour 50%+ of endemic plant species and 42% endemic terrestrial vertebrates). India has 4 hotspots: Western Ghats & Sri Lanka, Himalaya, Indo-Burma, and Sundaland.

4.2 Biodiversity Hotspots

Definition: Biodiversity hotspot = A region with exceptionally high species richness and endemism, but also facing exceptional threat of habitat loss. Concept introduced by Norman Myers (1988). Criteria: must contain >1,500 endemic plant species AND has lost >70% of its original habitat.

Hotspot in India	Notable Species
Western Ghats & Sri Lanka	Lion-tailed macaque, Purple frog, Nilgiri tahr
Himalaya	Snow leopard, Red panda, One-horned rhinoceros
Indo-Burma	Irrawaddy dolphin, Green peacock
Sundaland (Nicobar Islands)	Colugo (flying lemur), Nicobar pigeon

⚠️ NEET Focus (2015, 2018, 2020): Globally 34 hotspots. India has 4 hotspots. Hotspot criteria: >1,500 endemic plant species + >70% habitat lost. Coined by Norman Myers (1988). Hotspots cover <2% of Earth's land but house 50% of all endemic plant species.

4.3 Sacred Groves

Forest patches around places of worship, protected by tribal communities. Rich in biodiversity. Examples: Khasi hills (Meghalaya), Aravalli (Rajasthan), Sarguja (Chhattisgarh), Kodagu (Karnataka).

4.4 Ex Situ Conservation (Off-site / Away from Natural Habitat)

Definition: Ex situ conservation = protecting species outside their natural habitat, in controlled environments.

Method	Examples / Details
Zoological Parks (Zoos)	Captive breeding of endangered animals. National Zoological Park, Delhi.
Botanical Gardens	Living plant collections. Royal Botanic Gardens, Kew (UK); Howrah Botanical Garden (India).
Seed Banks	Seeds stored at -196°C (liquid N₂). National Bureau of Plant Genetic Resources (NBPGR), New Delhi. Svalbard Global Seed Vault, Norway.
Gene Banks / Cryopreservation	Gametes, embryos, pollen stored in liquid nitrogen for indefinite periods.
In-vitro Fertilisation (IVF)	Captive breeding using artificial reproductive techniques.
Tissue Culture	Cell/tissue preservation and clonal propagation of plants.

⚠️ NEET Focus (2013, 2016, 2019, 2022): In situ > Ex situ (in situ is preferred). Seed banks store seeds at −196°C (liquid nitrogen). Zoological parks = ex situ. IUCN Red List = 784 extinctions since 1600. Project Tiger (1973) and Project Elephant (1992) — India-specific conservation programmes.

5. International Efforts in Conservation

Convention / Programme	Year	Purpose
Convention on Biological Diversity (CBD)	1992 (Rio Earth Summit)	Framework for conservation of biodiversity and fair sharing of benefits.
CITES	1973	Convention on International Trade in Endangered Species — regulates wildlife trade.
Ramsar Convention	1971	Protection of wetlands of international importance.
World Heritage Sites (UNESCO)	1972	Protection of natural and cultural heritage sites globally.
Nagoya Protocol	2010	Access and benefit sharing of genetic resources (ABS framework under CBD).
IUCN Red List	Ongoing	Categories: Extinct, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern.

📋 Project Tiger: Launched in 1973 under PM Indira Gandhi. Current tiger numbers in India: ~3,167 (2022 census). India has ~70% of world's wild tigers. Tiger Reserves: 54 (as of 2023). First reserve: Jim Corbett National Park (Uttarakhand).

⚠️ NEET Focus (2014, 2017, 2020): CBD — 1992, Rio. CITES — 1973. Ramsar — 1971 (wetlands). Project Tiger — 1973. First tiger reserve = Jim Corbett. IUCN Red List categories: EX, EW, CR, EN, VU, NT, LC. World Conservation Union = IUCN.

🎓 Key NEET Questions (Previous Years)

Q1. [NEET 2022] Which is the most important cause of biodiversity loss globally?

(a) Over-exploitation (b) Alien species invasions (c) Habitat loss and fragmentation (d) Co-extinctions

Answer: (c) Habitat loss and fragmentation is the most important cause — especially deforestation of tropical forests for agriculture and urbanization. It directly destroys the living space of species.

Q2. [NEET 2019] Biodiversity hotspots are regions that have:

(a) High species diversity only (b) High endemism but minimum threat (c) High species richness and high degree of endemism with high habitat loss (d) Low species richness but unique species

Answer: (c) Hotspots are defined by >1,500 endemic plant species AND >70% original habitat already lost. They must have both high endemism + high threat of habitat loss.

Q3. [NEET 2018] Which is an example of ex situ conservation?

(a) Wildlife sanctuary (b) Biosphere reserve (c) National Park (d) Seed bank

Answer: (d) Seed bank = ex situ (off-site) conservation. Wildlife sanctuaries, biosphere reserves, and national parks are all in situ conservation methods.

Q4. [NEET 2017] The species-area relationship (log S = log C + Z log A), the Z value for large continents is:

(a) 0.1–0.2 (b) 0.6–1.2 (c) 1.5–2.0 (d) 0.3–0.5

Answer: (b) For large continental areas, Z = 0.6–1.2. For smaller areas or islands, Z = 0.1–0.2.

Q5. [NEET 2016] The introduction of Nile perch into Lake Victoria caused:

(a) Eutrophication of the lake (b) Extinction of native cichlid fishes (c) Increased fish diversity (d) Decrease in water quality

Answer: (b) Nile perch being a voracious predator caused the extinction of over 200 endemic cichlid fish species in Lake Victoria — a classic example of alien invasive species causing co-extinction.

Q6. [NEET 2014] India contains how many biodiversity hotspots?

(a) 2 (b) 3 (c) 4 (d) 6

Answer: (c) India has 4 biodiversity hotspots: Western Ghats & Sri Lanka, Himalaya, Indo-Burma, and Sundaland (Nicobar Islands).

💡 Rapid Revision — Key Numbers

Documented species: ~1.5 million | Estimated total: ~7 million (Robert May)
India: >45,000 plant species | >89,000 animal species | 8.1% global species diversity on 2.4% land
Hotspots globally: 34 | In India: 4 | Criteria: >1,500 endemic plants + >70% habitat lost
Protected areas in India: 18 biosphere reserves | 106 national parks | 567 wildlife sanctuaries
Evil Quartet: Habitat loss, Over-exploitation, Alien species, Co-extinctions
Project Tiger: 1973 | First reserve: Jim Corbett | India = ~70% world's wild tigers
CBD: 1992 (Rio) | CITES: 1973 | Ramsar: 1971
Tropical forests: <10% of Earth's surface but >50% of all species
Seed banks: −196°C (liquid nitrogen). Z slope: islands = 0.1–0.2; continents = 0.6–1.2

NCERT Solutions - Biodiversity and Conservation - Class 12

CLASS 12 BIOLOGY | NCERT SOLUTIONS

Chapter 15 — Biodiversity and Conservation

All NCERT Exercise Questions with Detailed Solutions

📋 Note: All questions from NCERT Class 12 Biology Chapter 15 Exercise. Answers as per NCERT and CBSE marking scheme.

NCERT Exercise Questions & Solutions

1 Mark Q1. Name the three levels of biodiversity.

✓ Answer
The three levels of biodiversity are:
1. Genetic Diversity — Variation in genetic composition within a species (e.g., >50,000 strains of rice in India).
2. Species Diversity — Variety of species in a region; measured by species richness and evenness.
3. Ecological (Ecosystem) Diversity — Variety of ecosystems in a region (e.g., deserts, rainforests, wetlands).

2 Marks Q2. How do ecologists estimate the total number of species present in the world?

✓ Answer
Ecologists use statistical comparisons of well-studied groups to estimate the total number of species:

Species richness comparison: In a well-known tropical group (e.g., insects in a tropical forest), ecologists estimate the species richness. This ratio is then extrapolated to lesser-known groups and regions.
Robert May's estimate: By comparing the fraction of well-described species in well-studied groups and applying correction factors, he estimated ~7 million total species on Earth (currently only ~1.5 million described).
Statistical extrapolation: Using known taxonomic ratios (e.g., ratio of described to undescribed species in insects), estimates are made for all groups.

3 Marks Q3. Give three hypotheses for explaining why tropics show greatest levels of species richness.

✓ Answer

Greater evolutionary time (speciation time): Tropical environments have remained relatively undisturbed for millions of years (unlike temperate regions affected by glaciation). This has allowed more time for speciation and diversification of species.
Higher solar energy and productivity: Tropics receive more solar energy throughout the year, leading to higher net primary productivity. More energy supports more diverse food webs and greater species richness.
Less seasonal variation and niche specialization: Constant and predictable environment (no harsh winters) allows greater niche specialization over evolutionary time — promoting species diversification and coexistence of more species in the same area.

2 Marks Q4. What is the significance of slope Z in the equation log S = log C + Z log A?

✓ Answer
In the species-area relationship (Alexander von Humboldt), Z is the slope of the regression line (on a log-log scale).

Significance of Z:

Z indicates the rate at which species richness increases with increasing area.
For smaller areas or islands: Z = 0.1–0.2 (gradual increase)
For large continental areas: Z = 0.6–1.2 (sharp increase)

A higher Z value means species diversity is more area-dependent — reducing habitat area will cause a sharper decline in species richness.

3 Marks Q5. What are the major causes of biodiversity loss? (The Evil Quartet)

✓ Answer
Jared Diamond identified four major causes called the Evil Quartet:

Habitat Loss and Fragmentation: Most important cause. Deforestation of tropical rainforests for agriculture and urbanisation destroys species' living space. Fragmentation isolates populations, preventing gene flow.
Over-Exploitation: Excessive hunting, fishing, and harvesting beyond sustainable limits. Examples: Steller's sea cow (1768), Passenger pigeon (1914), Dodo (1690s).
Alien Species Invasions: Introduction of non-native species disrupts native ecosystems. Example: Nile perch in Lake Victoria → >200 cichlid fish extinct. Invasive plants: Water hyacinth, Parthenium.
Co-extinctions: When one species goes extinct, obligately associated species (mutualists, parasites, pollinators) also go extinct. Example: Coevolved plant-pollinator pairs.

5 Marks Q6. How is biodiversity important for ecosystem functioning?

✓ Answer
Biodiversity is fundamental to ecosystem functioning through the following ways:

Productivity: More species → more complete use of available resources → higher overall productivity. Diverse grasslands produce more biomass than monocultures.
Stability and Resilience: Greater biodiversity → greater resistance to perturbations and faster recovery after disturbances. “Rivet Popper Hypothesis” (Paul Ehrlich) — each species is like a rivet in a plane wing.
Nutrient Cycling: Diverse decomposers, producers, and consumers ensure efficient nutrient cycling through the ecosystem.
Energy Flow: Complex food webs with more species ensure more stable energy flow and reduce vulnerability of the system to collapse.
Ecosystem Services: Biodiversity underpins ecosystem services — water purification, soil formation, pollination, climate regulation — estimated at US$ 33 trillion/year.
Genetic Resources: Biodiversity maintains the genetic diversity needed for adaptation to changing environments and future agricultural/medical needs.

3 Marks Q7. What are the in situ approaches to conservation? Give examples.

✓ Answer
In situ conservation = protecting species in their natural habitat. It is the preferred approach as it conserves entire ecosystems, food webs, and natural behaviours.

Types in India:

Type	Example
Biosphere Reserves (18)	Nilgiri, Nanda Devi, Sundarbans
National Parks (106)	Corbett, Kaziranga, Periyar, Kanha
Wildlife Sanctuaries (567)	Vedanthangal, Chilika, Sultanpur
Sacred Groves (thousands)	Khasi hills, Aravalli, Kodagu

India also has specific in situ conservation programmes: Project Tiger (1973) focusing on tiger conservation, and Project Elephant (1992) for Asian elephants.

3 Marks Q8. What are the ex situ approaches to conservation? Give examples.

✓ Answer
Ex situ conservation = protecting species outside their natural habitat in controlled environments.

Methods and Examples:

Zoological Parks: Captive breeding of threatened animals. Example: National Zoological Park, Delhi.
Botanical Gardens: Collection and study of living plants. Example: Royal Botanic Gardens, Kew; Indian Botanical Garden, Howrah.
Seed Banks: Seeds stored at −196°C (liquid nitrogen). Example: Svalbard Global Seed Vault; NBPGR, New Delhi.
Cryopreservation: Gametes, embryos, pollen stored in liquid nitrogen indefinitely.
Tissue Culture / In vitro Techniques: Preservation and clonal propagation of plants.

Ex situ methods are critical when in situ methods fail (species near extinction) or natural habitat is completely destroyed.

2 Marks Q9. What is the IUCN Red List? How does it classify threatened species?

✓ Answer
The IUCN Red List (International Union for Conservation of Nature) is a global inventory evaluating the conservation status of species.

IUCN Red List Categories:

EX — Extinct (no individuals remaining)
EW — Extinct in the Wild (only in captivity)
CR — Critically Endangered
EN — Endangered
VU — Vulnerable
NT — Near Threatened
LC — Least Concern

As per the 2004 IUCN list, ~784 species have gone extinct since 1600 AD, and ~15,500 species are currently threatened.

2 Marks Q10. Briefly discuss the three arguments that justify biodiversity conservation.

✓ Answer

Narrowly Utilitarian (Economic value): Nature provides humans with food, fibre, medicines (~25% of drugs from plants), industrial products, and other direct economic benefits.
Broadly Utilitarian (Ecosystem services): Biodiversity provides essential ecosystem services — O₂ production, pollination, water purification, climate regulation, soil formation — worth US$ 33 trillion/year.
Ethical (Intrinsic value): Every species has an inherent right to exist. We have a moral duty to conserve species for future generations. (“We share this planet with other species” argument).

Facts Capsule - Biodiversity and Conservation - Class 12

CLASS 12 BIOLOGY | NEET RAPID CAPSULE

Facts & High-Yield Points

Chapter 15 — Biodiversity and Conservation | 28 Key Facts for NEET

🌿 Biodiversity Basics

FACT #01 — Term & Levels

“Biodiversity” popularised by Edward Wilson. Three levels: Genetic (within species), Species (between species), Ecosystem (variety of ecosystems).

FACT #02 — India's Share

India has 2.4% of world's land but 8.1% of global species diversity. >45,000 plant species (13th rank) | >89,000 animal species | >50,000 rice strains | >1,000 mango varieties.

FACT #03 — Global Species

Documented: ~1.5 million species. Robert May's estimate: ~7 million total. Insects are the most species-rich group (~10 lakh named species).

FACT #04 — Species-Area Relationship

Formulated by Alexander von Humboldt. Formula: log S = log C + Z log A. Z = 0.1–0.2 (small/islands), Z = 0.6–1.2 (large continents).

FACT #05 — Latitudinal Gradient

Species richness increases towards equator. Tropics (<10% land) harbour >50% of all species. Colombia: ~1,400 birds. Amazon: 40,000 plant spp. + 1,300 bird spp.

FACT #06 — Why Tropics are Richer

(1) More evolutionary time (no glaciation). (2) Higher solar energy → productivity. (3) Constant climate → niche specialization. These three arguments from NCERT.

🟥 Biodiversity Loss

FACT #07 — Scale of Loss

>784 species extinct since 1600 (IUCN 2004). ~15,500 species currently threatened. Extinction rate = 100–1000x natural background rate. Earth heading toward 6th mass extinction.

FACT #08 — Evil Quartet (Jared Diamond)

Habitat loss (most important) | Over-exploitation | Alien invasions | Co-extinctions. Mnemonic: HOAC.

FACT #09 — Extinct Species

Dodo: Mauritius, 1690s. Passenger pigeon: 1914 (Martha = last individual). Steller's sea cow: 1768. Quagga (zebra relative): 1883.

FACT #10 — Alien Invasions

Nile perch → Lake Victoria → >200 cichlid fish extinct. Water hyacinth (Eichhornia crassipes) in India. Parthenium hysterophorus = invasive weed. African catfish Clarias gariepinus in India.

🔒 Conservation

FACT #11 — In Situ (India)

18 Biosphere Reserves | 106 National Parks | 567 Wildlife Sanctuaries | Thousands of Sacred Groves. In situ = most preferred method.

FACT #12 — Ex Situ Methods

Zoological parks, Botanical gardens, Seed banks (−196°C, liquid N₂), Cryopreservation, Tissue culture, IVF. NBPGR, New Delhi = National Seed Bank. Svalbard = Global Seed Vault.

FACT #13 — Project Tiger

Launched: 1973, PM Indira Gandhi. First reserve: Jim Corbett NP (Uttarakhand). Tiger reserves in India: 54. India = ~70% of world's wild tigers (~3,167 in 2022).

FACT #14 — Arguments for Conservation

(1) Narrowly utilitarian: economic use, medicines. (2) Broadly utilitarian: ecosystem services (~US$ 33 trillion/yr). (3) Ethical: intrinsic value — right to exist.

FACT #15 — Rivet Popper Hypothesis

By Paul Ehrlich. Species are like rivets in a plane wing. Lose too many → catastrophic ecosystem failure. Each extinction increases ecosystem collapse risk.

FACT #16 — Sacred Groves

Forest patches protected by tribal/local communities for religious reasons. Rich in biodiversity; unofficial conservation. Examples: Khasi hills (Meghalaya), Kodagu (Karnataka), Aravalli (Rajasthan).

🔥 Biodiversity Hotspots

FACT #17 — Hotspot Definition

Coined by Norman Myers (1988). Criteria: >1,500 endemic plant species AND has lost >70% of original habitat. Globally: 34 hotspots. Cover <2% land but house >50% endemic plant species.

FACT #18 — India's 4 Hotspots

1. Western Ghats & Sri Lanka (Lion-tailed macaque, Purple frog). 2. Himalaya (Snow leopard, Red panda). 3. Indo-Burma (Irrawaddy dolphin). 4. Sundaland / Nicobar (Nicobar pigeon).

FACT #19 — Tropical vs Temperate

Tropical forests = <10% of Earth surface but >50% of all species. More than 80% of freshwater biodiversity is in tropical regions. High endemism = characteristic of hotspots.

🌎 International Conventions

FACT #20 — CBD (1992)

Convention on Biological Diversity. Rio Earth Summit, 1992. Framework for conservation + equitable benefit sharing of biodiversity. India is a signatory.

FACT #21 — CITES (1973)

Convention on International Trade in Endangered Species. Regulates global wildlife trade to prevent overexploitation. Lists species in Appendix I, II, III.

FACT #22 — Ramsar (1971)

International treaty on wetlands of international importance. Chilika Lake, Loktak Lake = Ramsar sites in India. Signed in Ramsar, Iran.

FACT #23 — IUCN Red List Categories

FACT #24 — Amazon Forest

Amazon = 20% of Earth's O₂. Called “Lungs of the Earth”. Houses ~40,000 plant spp., 3,000 fish spp., 1,300 birds. Ecosystem services = US$ 33 trillion/year globally.

🧠 Mnemonics — Remember Fast

Evil Quartet: “HOAC” Habitat loss (most important) | Over-exploitation | Alien invasions | Co-extinctions.

India's Hotspots: “WE HIS” Western Ghats + Sri Lanka | Himalaya | Indo-Burma | Sundaland.

IUCN Levels: “EE CR VU NT-LC” Extinct → EW → Critically Endangered → Endangered → Vulnerable → NT → Least Concern.

3 Arguments: “NUE” Narrowly utilitarian | Utilitarian (broadly) | Ethical. (NUE = No Unethical Exploitation!).

📊 In Situ vs Ex Situ Conservation

Feature	In Situ	Ex Situ
Location	Natural habitat (on-site)	Outside natural habitat
Examples	National Parks, Sanctuaries, Biosphere Reserves, Sacred Groves	Zoos, Botanical gardens, Seed banks, Cryopreservation
Preference	Primary / Most Preferred	Secondary / Supplementary
Ecosystem	Entire ecosystem conserved	Only individual species/genomes
Cost	Lower operational cost	Higher setup and maintenance cost
India count	18 BR + 106 NP + 567 WS	NBPGR (seed bank), zoos, botanical gardens

🔢 Critical Numbers — Never Forget

1.5 million — described species 7 million — Robert May's estimate 45,000+ — plant species in India 89,000+ — animal species in India 8.1% — India's share of world species 2.4% — India's land share 784 — extinctions since 1600 34 — global hotspots 4 — India's hotspots 1,500 — endemic plants (hotspot criterion) 70% — habitat lost (hotspot criterion) 18 — biosphere reserves (India) 106 — national parks (India) 567 — wildlife sanctuaries (India) 1973 — Project Tiger launched −196°C — seed bank temperature

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