Complete Guide to Biodiversity & Conservation
💎 3 GOLDEN FACTS (NEET 2015-24)
⚖️ IN-SITU vs EX-SITU CONSERVATION
| Feature | In-Situ | Ex-Situ | NEET Examples |
|---|---|---|---|
| Definition | On-site conservation | Off-site conservation | 2 Q/yr |
| Methods | National parks, Sanctuaries | Zoos, Seed banks | 1 Q/yr |
| Advantages | Natural habitat maintained | Protection from predators | 1 Q/2yr |
🌍 Biodiversity Fundamentals
Three Levels of Biodiversity:
- Genetic Diversity: Variation within species (e.g., different rice varieties - over 50,000 strains in India alone)
- Species Diversity: Variety of species in a region (measured by species richness and evenness - Western Ghats have over 7,400 flowering plant species)
- Ecological Diversity: Variety of ecosystems (e.g., forests, deserts, wetlands - India has 10 biogeographic zones)
🌐 Global Biodiversity Patterns
Key Concepts:
- Latitudinal gradient: Diversity increases from poles to tropics (Amazon rainforest has 10% of world's species in just 0.5% land area)
- Species-Area relationship: S = CAz (logarithmic relationship where z typically ranges 0.1-0.2 for continents)
- Rivet Popper Hypothesis: Paul Ehrlich's analogy comparing species to rivets in an airplane - losing some may be okay, but eventually the plane crashes
Amazon rainforest (highest biodiversity with ~400 billion trees) vs Arctic tundra (lowest with only ~1,700 plant species)
"LAT" - Latitudinal, Area, Time (three main factors affecting biodiversity patterns)
🎯 PYQ Highlights:
NEET 2021: Which hypothesis explains why we should conserve biodiversity even if we don't know all species' functions? Answer: Rivet Popper Hypothesis
NEET 2019: Maximum biodiversity occurs at which latitude? Answer: Tropical regions (23.5°N to 23.5°S)
NEET 2017: What does 'S' represent in the species-area relationship formula? Answer: Species richness
🧠 EVIL-S FACTORS (Biodiversity Loss)
"E - Exploitation, V - Vanishing habitat, I - Invasion, L - Loss of keystone, S - Secondary extinction"
Major threats to biodiversity according to NEET syllabus with examples:
- Exploitation: Overhunting (Dodo, Passenger pigeon)
- Vanishing habitat: Deforestation (Amazon losing 20,000 sq mi annually)
- Invasion: Alien species (Lantana in Indian forests)
NEET Hack: Remember "EVIL-S" for all biodiversity loss factors - has appeared in 3 PYQs
🔥 Biodiversity Hotspots
Criteria for Hotspots (Norman Myers, 1988):
- Must contain ≥ 1,500 endemic vascular plants (0.5% of world's total)
- Must have lost ≥ 70% of primary vegetation (based on satellite data)
- 36 global hotspots covering just 2.4% Earth's land but containing 50% plant and 42% vertebrate species
India's Four Hotspots:
- Himalayas: Eastern Himalaya (7,500 flowering plants) more diverse than Western (5,000 species). Includes Snow leopard, Red panda.
- Indo-Burma: Includes NE India and Andaman Islands. Home to Hoolock gibbon, Pygmy hog.
- Western Ghats: 1,600+ endemic plant species (40% endemism). Lion-tailed macaque, Nilgiri tahr.
- Sundaland: Only Nicobar Islands in India. Has Nicobar megapode, Nicobar tree shrew.
NEET Must Know: Western Ghats have highest endemism in India (63% amphibians, 53% reptiles)
🎯 PYQ Highlights:
NEET 2022: Which is not an Indian biodiversity hotspot? Answer: Thar Desert
NEET 2020: Minimum % area lost for hotspot status? Answer: 70%
NEET 2018: Which Indian hotspot has highest amphibian diversity? Answer: Western Ghats
🧠 HOTSPOT Mnemonic
"H - High endemism, O - Original habitat lost, T - Threatened species, S - Small area, P - Protection needed, O - Over 1500 plants, T - Tropical"
Remember all hotspot criteria with this easy mnemonic
🛡️ Biodiversity Conservation
Conservation Approaches:
- In-situ: Conservation in natural habitat (National parks - 104 in India, Wildlife sanctuaries - 553, Biosphere reserves - 18)
- Ex-situ: Conservation outside natural habitat (Zoos - 150+ in India, Botanical gardens - 33 A-class, Seed banks - 6 at NBAGR)
- Community-based: Sacred groves (13,000+ in India), Joint forest management (covering 22% Indian forests)
IUCN Red List Categories (2023 Update):
- Extinct (EX): No individuals remaining (Dodo, 1681; Pink-headed duck, 1950s)
- Critically Endangered (CR): Extremely high risk (Great Indian Bustard <150 left, Sumatran rhino <80)
- Endangered (EN): Very high risk (Bengal Tiger ~3,000, Asian elephant ~50,000)
- Vulnerable (VU): High risk (Snow leopard ~4,000, Olive ridley turtle)
- Near Threatened (NT): Close to qualifying (Blue sheep, Indian flying fox)
2023 Update: 42,100 species threatened (28% assessed), 902 extinct
🎯 PYQ Highlights:
NEET 2021: Which organization maintains Red Data Book? Answer: IUCN (International Union for Conservation of Nature)
NEET 2018: Most endangered Indian avian species? Answer: Great Indian Bustard (CR with <150 individuals)
NEET 2016: Example of ex-situ conservation? Answer: Seed bank at National Bureau of Plant Genetic Resources
Modern Conservation Techniques:
-196°C storage (testes of Indian rhino at CCMB)
Svalbard Global Seed Vault (1 million+ samples)
IVF for Cheetah reintroduction
🏞️ Protected Areas in India
Key Differences (Wildlife Protection Act, 1972):
- National Park (104): No human activity allowed (except tourism in buffer). Example: Kaziranga (rhino), Hemis (largest, snow leopard)
- Wildlife Sanctuary (553): Limited human activity allowed (grazing with permit). Example: Bharatpur (birds), Periyar (tiger)
- Biosphere Reserve (18): Three zones (core - no human, buffer - limited, transition - sustainable use). Example: Nilgiri (first), Sundarbans (largest mangrove)
Sacred Groves (Community Conservation):
Examples:
- Khasi Hills (Meghalaya): 1,000+ groves (highest concentration), protect Daphne papyracea
- Aravalli Hills (Rajasthan): Oran groves conserve Prosopis cineraria
- Western Ghats (Karnataka): Devara kadus conserve Dipterocarpus indicus
NEET Focus: Best examples of in-situ conservation by local communities (13,000+ groves conserving 4,000+ plant species)
🎯 PYQ Highlights:
NEET 2020: Which has core, buffer and transition zones? Answer: Biosphere Reserve
NEET 2019: Largest national park in India? Answer: Hemis National Park, Ladakh (4,400 sq km)
NEET 2017: Example of community conservation? Answer: Sacred groves of Meghalaya
🧠 PAWS Mnemonic (Protected Areas)
"P - Protection level, A - Area covered, W - Wildlife focus, S - Scientific research"
Remember key aspects of protected areas for NEET questions
📈 NEET 2025 Predictions
High Probability Topics (90% chance):
- Indian biodiversity hotspots (Western Ghats vs Himalayas comparison)
- IUCN Red List categories (CR vs EN vs VU distinctions with examples)
- Difference between national park and sanctuary (legal protection levels)
- Ex-situ vs in-situ conservation (2-3 marks guaranteed)
Dark Horse Candidates (Surprise Elements):
- Sacred groves as community conservation (increasing focus on traditional knowledge)
- Keystone species examples (Fig tree - supports 1,200 wasp species, Elephant - creates water holes)
- Recent extinct species (Pink-headed duck - last seen 1950s, declared 2023)
- Biosphere reserve zones (core vs buffer vs transition - 1 mark definition)
2025 Special: Expect a question on Project Cheetah reintroduction (ex-situ to in-situ case study)
🧠 Mnemonics & Quick Recall
H - High endemism (1,500+ plants)
O - Original habitat lost (70%+)
T - Threatened species present
S - Small area (≤2.4% land)
P - Protection needed urgently
E - Extinct (EX)
C - Critically Endangered (CR)
E - Endangered (EN)
V - Vulnerable (VU)
N - Near Threatened (NT)
L - Least Concern (LC)
N - National Park (strict)
S - Sanctuary (less strict)
B - Biosphere Reserve (3 zones)
C - Conservation Reserve
C - Community Reserve
💡 NEET 2025 Master Strategy
- ✅ Memorize all 4 Indian hotspots with 2 endemic species each (Western Ghats: Lion-tailed macaque, Nilgiri tahr; Himalayas: Snow leopard, Red panda)
- ✅ Practice IUCN categories with 2 examples each (CR: Great Indian Bustard, Sumatran rhino; EN: Bengal Tiger, Asian elephant)
- ✅ Solve all PYQs on protected areas (2015-2024) focusing on legal differences (NP vs WS vs BR)
- ✅ Create comparison charts for in-situ vs ex-situ with methods and examples
With these strategies, you'll dominate the 4-6 marks from Biodiversity section in NEET 2025! 🌿🦚
