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Biodiversity ​

📊 High-Yield Data & Statistical Fact Sheet
  • India's Global Biodiversity Footprint:
    • Global Share: India represents ~7% to 8% of the world's recorded species on only 2.4% of the Earth's land surface.
    • Megadiverse Status: India is one of the 17 Megadiverse Countries globally.
  • Tiger & Elephant Population Metrics:
    • Tigers: India hosts >70% of the world's wild tigers. The 2022 Tiger Census recorded 3,167 tigers (MP leads with 526, followed by Karnataka with 524).
    • Elephants: India hosts >60% of the wild Asiatic elephant population. The population stands at 29,964 (Karnataka leads, followed by Assam). Includes 33 Elephant Reserves (Karnataka hosts the largest wild elephant population).
  • Biodiversity Hotspots & Protection Sites:
    • Hotspots: India has 4 Biodiversity Hotspots (Himalayas, Western Ghats, Indo-Burma, Sundaland).
    • Biosphere Reserves: India has 18 Biosphere Reserves (12 recognized under UNESCO's WNBR).
    • Tiger Reserves: India has 58 Tiger Reserves (Sundarbans expanded to become the 2nd largest; Nagarjunsagar-Srisailam is the largest).

1. DIVERSITY MEASUREMENTS & ECOLOGICAL LABELS ​

Biodiversity refers to the variety of life at genetic, species, and ecosystem levels:

  • Species Richness vs. Species Evenness:
    • Species Richness: The total number of distinct species present in a defined community.
    • Species Evenness: The relative abundance of individuals among different species. Low evenness means a few species dominate the ecosystem.
  • Whittaker's Diversity Metrics:
    • Alpha Diversity: Local diversity within a single defined ecosystem or habitat, measured as species richness.
    • Beta Diversity: The rate of species turnover (change in species composition) between different ecosystems along an environmental gradient.
    • Gamma Diversity: The total regional species diversity across all habitats in a large geographic area: $$\text{Gamma} \approx \text{Alpha} \times \text{Beta}$$
                ┌─── [Alpha (Local)] ──────► Species richness in ONE habitat
                │
 [Whittaker] ───┼─── [Beta (Turnover)] ────► Change in species BETWEEN habitats
                │
                └─── [Gamma (Regional)] ───► Total regional species diversity
  • Functional Categories of Species:
    • Keystone Species: A species that has a disproportionately large impact on its community relative to its low abundance (e.g., Tigers, Sea Otters, Elephants).
    • Indicator Species: A species highly sensitive to environmental change, acting as an early warning signal for ecosystem health (e.g., Lichens for $SO_2$ air pollution, Frogs/Amphibians for water quality).
    • Umbrella Species: Species with large habitat requirements; protecting them automatically conserves numerous other co-existing species (e.g., Tigers, Greater One-horned Rhinoceros).
    • Foundation Species: Abundant primary producers that build, structure, and dominate the physical habitat (e.g., Coral polyps forming reefs, Kelp forming kelp forests).
    • Flagship Species: Iconic, charismatic species used as ambassadors to build public support for conservation campaigns (e.g., Giant Panda, Bengal Tiger, Asian Elephant).

2. ECOLOGICAL ADAPTATIONS & MICROBIAL DIVERSITY ​

  • Ecological Adaptations:
    • Behavioural: Actions taken to survive, such as Torpor (a short-term drop in body temperature and metabolic rate to survive cold/dry spells) vs. Hibernation (long-term winter sleep) and Aestivation (summer dormancy).
    • Plant Adaptations:
      • Xerophytes: Adapted to dry soils; characterized by thick waxy cuticles, sunken stomata, deep taproots, and CAM Photosynthesis (opening stomata at night to prevent daytime water loss).
      • Hydrophytes: Adapted to aquatic environments; characterized by reduced root systems, stomata on the upper leaf surface, and aerenchyma (spongy, air-filled tissue for buoyancy).
      • Halophytes: Salt-tolerant coastal plants; characterized by breathing roots (pneumatophores), vivipary (seed germination while attached to the parent plant), and specialized salt-secreting glands.
  • Microbial & Invertebrate Diversity:
    • Prokaryotes vs. Eukaryotes: Prokaryotes (Bacteria, Archaea) lack membrane-bound nuclei and organelles, whereas Eukaryotes (Fungi, Protists, Plants, Animals) possess defined nuclei.
    • Viruses vs. Sub-viral Agents: Viruses contain DNA or RNA within a protein coat. Prions are infectious, misfolded proteins without genetic material. Viroids are naked, infectious RNA molecules without a protein coat.
    • Biofertilizers: Microorganisms that enhance nutrient availability (e.g., Rhizobium in legume root nodules, Azotobacter, and the Azolla-Anabaena symbiosis in flooded rice paddies).
    • Insect Sociality: E.g., Honeybees, Ants, and Termites. Honeybees perform the Wiggle Dance to communicate the direction (relative to the sun) and distance of food sources.

3. BIODIVERSITY LANDSCAPE OF INDIA ​

India is divided into distinct biogeographic zones hosting unique flora and fauna:

  • Himalayan Foothills (Terai): Characterized by tall alluvial grasslands and Sal forests. Home to the Great Indian One-horned Rhinoceros, Swamp Deer (Barasingha), Tiger, and Asian Elephant.
  • Western Himalayas: High-altitude alpine pastures and birch forests. Home to the Snow Leopard, Tibetan Wild Ass (Kiang), Blue Sheep (Bharal), and Alpine Musk Deer.
  • Eastern Himalayas: Moist evergreen oak forests, rhododendrons, and abundant orchids. Home to the Red Panda and Takin.
  • Peninsular India: Deciduous teak and sal forests. Home to the Gaur, Wild Boar, Chital, Sambar, and Blackbuck.
  • Indian Desert (Thar): Scrub forests dominated by Khejri (Prosopis cineraria), Ker, and Rohida. Home to the Great Indian Bustard (GIB), Desert Fox, and Caracal.
  • Tropical Rainforest (Western Ghats & North-East): Pristine rainforests hosting the Hoolock Gibbon (India's only wild ape), Golden Langur, and Lion-Tailed Macaque.
  • Andaman & Nicobar Islands: Equatorial rainforests and extensive mangroves. Home to the Dugong (Sea Cow) and Narcondam Hornbill.
  • Invasive Alien Flora: Highly disruptive non-native plants including Lantana camara, Water Hyacinth (Eichhornia crassipes), and Parthenium hysterophorus.
  • Critical Species-Site Mapping:
    • gir (Gujarat): Asiatic Lion
    • Chambal River: Gharial (Critically Endangered freshwater crocodilian)
    • Loktak Lake (Manipur): Sangai (Dancing Deer, dependent on floating phumdis)
    • Western Ghats: Lion-Tailed Macaque (Endemic rainforest arboreal primate)
    • Dachigam (J&K): Hangul (Kashmir Stag, endangered cervid species)
    • Desert NP (Rajasthan): Great Indian Bustard (GIB, grassland flagship species)
    • Little Rann of Kutch: Indian Wild Ass (Khur, endemic saline desert mammal)

4. CONSERVATION PROJECTS & 2025–2026 REGULATORY UPDATES ​

  • Statutory Protection & Wildlife Laws:
    • WPA 1972 Schedules (2022 Amendment): Streamlined from 6 down to 4 schedules:
      • Schedule I: Affords the highest level of legal protection (e.g., Tigers, Asiatic Lions, Great Indian Bustards). Hunting is strictly prohibited, and offenses carry the highest penalties.
      • Schedule II: Protects species with a slightly lower scale of penalties (e.g., Spotted Deer, various reptile species).
      • Schedule III: Dedicated exclusively to protected plant species (e.g., Pitcher Plant, Red Vanda, Blue Vanda).
      • Schedule IV: Specially designated for species listed under CITES to regulate international commercial trade.
    • Kerala WPA Amendment (2025): The first state to authorize local authorities to order the lethal removal of wild animals posing immediate threats to human life.
  • Biological Diversity (ABS) Regulations, 2025:
    • Digital Sequence Information (DSI): Benefit-sharing rules are now extended to access to digital genomic sequence data (DNA/RNA).
    • Turnover Thresholds: Commercial entities utilizing Indian bio-resources with a turnover $> \text{₹1 Crore}$ must submit annual statements and pay access charges ranging from 0.1% to 0.6% of sales.
    • NBA Powers: The National Biodiversity Authority is vested with the powers of a Civil Court.
  • CSS-IDWH Species Recovery:
    • Sloth Bear and Gharial were added to the recovery program. The Daroji Sloth Bear Sanctuary (Karnataka) is recognized as Asia's first dedicated sloth bear sanctuary.
  • Project Tiger & Cheetah Updates (2025):
    • Tiger Reserves: Expanded to 58 reserves (including Madhav and Ratapani in MP). The Supreme Court banned tiger safaris and night tourism within the core zones and corridors of tiger reserves.
    • Project Cheetah Milestones: Reached 30 cheetahs in Kuno NP (MP). Botswana translocation finalized. Gandhi Sagar Wildlife Sanctuary (MP) on the Chambal River is ready as the second translocation site.
    • International Big Cat Alliance (IBCA): Headquartered in New Delhi to coordinate global big cat conservation.
  • Species DNA & AI Profiling:
    • Assam deployed the RhoDIS (Rhino DNA Index System) database to profile rhino horns.
    • The Snow Leopard population is tracked using the CaTRAT (AI camera trap database) under the multilateral Samarakhand Resolution.

5. PROTECTED AREAS: ZONES, ESZ & GEOLOGY ​

      [Core Zone]         ──► Strict legal protection (NP/WLS status)
           │
     [Buffer Zone]        ──► Regulated research, tourism, and community forestry
           │
   [Transition Zone]      ──► Sustainable agriculture and human settlements
  • Biosphere Reserves Zonation:
    • Core Area: Securely protected sites for conserving biological diversity, where human activity is prohibited.
    • Buffer Zone: Surrounds the core area; used for cooperative activities compatible with sound ecological practices (e.g., environmental education, ecotourism).
    • Transition Area: The outer zone where local communities, management agencies, and scientists work together to manage and sustainably develop the area's resources.
  • Eco-Sensitive Zones (ESZ): Fragile areas within 10 km of National Parks and Wildlife Sanctuaries, declared under the Environment (Protection) Act, 1986.
    • Prohibited: Commercial mining, stone quarrying, polluting industries, and large hydroelectric projects.
    • Regulated: Tree felling, commercial water extraction, and resort construction.
    • Permitted: Organic farming, rainwater harvesting, and renewable energy.
  • Conservation Reserves vs. Community Reserves: Conservation reserves are declared on government land, while community reserves are declared on private or community land. The Tsarap Chu Conservation Reserve (HP) in the Spiti Valley is India's largest conservation reserve.
  • Geo-Heritage Site Updates (2025): The Salkhan Fossil Park (UP), containing 1.4-billion-year-old stromatolites recording the Great Oxidation Event, was added to the UNESCO tentative list.

6. IUCN RED LIST OF THREATENED FAUNA OF INDIA ​

  • Critically Endangered (CR):
    • Hangul (Kashmir Stag): Restricted to Dachigam National Park (J&K); a subspecies of red deer.
    • Pygmy Hog: The world's smallest wild pig; native to grasslands in Manas National Park (Assam).
    • Great Indian Bustard (GIB): Large grassland bird; found in Desert National Park (Rajasthan).
    • Jerdon's Courser: Nocturnal cursorial bird; endemic to scrub jungles in Andhra Pradesh.
    • Gharial: Freshwater crocodilian; found in the National Chambal Sanctuary.
  • Endangered (EN):
    • Asiatic Lion: Found only in Gir National Park (Gujarat). Deemed "Largely Depleted" under the IUCN Green Status.
    • Red Panda: Endemic to temperate bamboo forests of the Eastern Himalayas.
    • Sangai (Brow-antlered Deer): Endemic to Keibul Lamjao National Park (Manipur).
    • Lion-tailed Macaque: Endemic to the canopy forests of the Western Ghats.
    • Nilgiri Tahr: State animal of Tamil Nadu; restricted to high-altitude montane grasslands in the Western Ghats.
    • Indian Pangolin: Scale-covered mammal heavily targeted by illegal wildlife trade.
  • Vulnerable (VU):
    • Snow Leopard: High-altitude predator across the Himalayas.
    • Greater One-horned Rhino: Inhabits alluvial grasslands in Assam (Kaziranga) and West Bengal.
    • Fishing Cat: Wetland-dwelling wild cat; found in Chilika Lake.
    • Olive Ridley Sea Turtle: Smallest sea turtle; famous for mass nesting (Arribada) in Odisha (Gahirmatha).

QUICK REVISION BOX ​

  • Alpha, Beta, Gamma: Alpha is local, Beta is turnover, Gamma is regional.
  • WPA 2022 Schedule IV: Specially designated for CITES-protected species.
  • Digital Sequence Information (DSI): Subject to benefit-sharing under BD Act 2025.
  • India's Wild Elephant Share: Hosts >60% of the global Asiatic elephant population.
  • Second Cheetah Habitat: Gandhi Sagar Wildlife Sanctuary (MP) on the Chambal River.
  • Stromatolite Site: Salkhan Fossil Park in Sonbhadra, UP.
  • Arribada nesting species: Olive Ridley Sea Turtle at Gahirmatha, Odisha.
  • Endemic Ape of India: The Hoolock Gibbon in the North-East.
  • Daroji Sanctuary Target: Dedicated to the conservation of the Sloth Bear.
  • Montreux Record Sites: Loktak Lake and Keoladeo National Park.

*Notes updated up to March 2026. Sources: IUCN Red List Portal, NTCA Bulletins, MoEFCC.

🎯 UPSC Prelims 2026 Questions & Explanations ​

Consider the following statements about Rhynchostylis retusa (Foxtail orchid)... - Question 26: Consider the following statements about Rhynchostylis retusa (Foxtail orchid):
1. It is an epiphytic orchid.
2. The species is endemic to North-east India.
3. It is the State flower of Arunachal Pradesh and Assam.
Which of the statements given above is/are correct?
(a) 1 only
(b) 1 and 3
(c) 2 and 3
(d) 3 only

Correct Answer: (B)

Key Concepts & Explanation:
Statement 1 is correct: Rhynchostylis retusa is commonly known as the "foxtail orchid" because the pendant inflorescence looks like a fox's tail. It is an epiphytic orchid distributed across the Indian subcontinent, China, Indochina, Malaysia, Indonesia, and the Philippines.
Statement 2 is incorrect: It is not endemic to Northeast India; it is also found in Bhutan, Cambodia, China, Indonesia, Laos, Myanmar, Nepal, Philippines, Singapore, Sri Lanka, Thailand, Vietnam, and in other Indian regions like Odisha and Andhra Pradesh.
Statement 3 is correct: Rhynchostylis retusa is the state flower of both Arunachal Pradesh and Assam.

Year Asked: Prelims 2026
Consider the following statements about the Hoolock Gibbon: 1. They... - Question 32: Consider the following statements about the Hoolock Gibbon:
1. They are mainly found in Northwest India.
2. They are listed on Schedule I of the Indian Wildlife Protection Act, 1972.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (B)

Key Concepts & Explanation:
Statement 1 is incorrect: Hoolock gibbons are mainly found in Northeast India (not Northwest). The Hollongapar Gibbon Sanctuary in Assam contains India's only ape and gibbon species.
Statement 2 is correct: Hoolock gibbons are listed on Schedule I of the Wildlife Protection Act, 1972, providing them with the highest level of legal protection. Their IUCN status is Endangered. Recently, a canopy bridge was constructed in Assam to help them bypass a railway track cutting through their habitat.

Year Asked: Prelims 2026
Which of the following is/are the most significant implication(s) o... - Question 39: Which of the following is/are the most significant implication(s) of obtaining Oeko-Tex certification for Eri Silk in the global textile industry?
1. It allows Indian exporters to compete in high-end markets that prioritise chemical-free products.
2. It confirms that Eri Silk meets international safety, environmental, and quality standards, enabling its entry into premium eco-conscious markets.
Select the answer using the code given below:
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (C)

Key Concepts & Explanation:
OEKO-TEX STANDARD 100 is a globally recognized label for textiles tested for harmful substances, setting the benchmark for safety from yarn to finished product. The Government of India successfully obtained this certification for Eri Silk, confirming it meets international safety, environmental, and quality standards. This crucial milestone enhances its global market appeal and allows Indian exporters to compete in premium eco-conscious and high-end markets prioritizing chemical-free products.

Year Asked: Prelims 2026
Site, is situated within this National Park. 3. Its area is shared ... - Question 22: Site, is situated within this National Park.
3. Its area is shared between Madhya Pradesh and Rajasthan.
Select the answer using the code given below:
(a) 1 only
(b) 1 and 2
(c) 2 and 3
(d) 3 only

Correct Answer: ()

Key Concepts & Explanation:
Jhansi road) about 5 km from Shivpuri town while the other is on NH-3 (Agra-Mumbai road) at a distance of 7 km from Shivpuri towards Gwalior.
Statement 2 is correct: Sakhya Sagar, a reservoir within the park, has been designated as a Ramsar site in 2022.
Statement 3 is not correct: It is entirely located in Madhya Pradesh
Tiger Reserve.
tally/article6930
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Hills. It also contains Sakhya Sagar, Madhav Sagar, and Madikhera Dam. It has recently been notified as the 58th tiger reserve of India.
Which of the following national parks is described in the passage above?
(a) Veerangana Durgavati national park
(b) Ratapani national park
(c) Mukundara national park
(d) Madhav national park
Tiger Reserve
5-04-16/env ironment/news-in-shorts# 58th-tiger-reserve

Year Asked: Prelims 2026
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