Why this topic matters for UPSC
Prelims: NCERT + current-affairs MCQs on biomes (rainforest · savanna · taiga · tundra · mangrove) · ecological pyramid · 10 % rule · GPP / NPP · trophic level · keystone vs umbrella vs flagship species · biogeochemical cycles · ecotone vs ecocline · primary vs secondary succession (hydrosere, xerosere) · Conservation International's 36 hotspots (India's 4) · IUCN Red List 9 categories · Project Tiger / Elephant / Cheetah / Dolphin / Lion / Snow Leopard · Biosphere Reserves (18 in India, 12 in UNESCO MAB list) · Ramsar (85+ sites) · Tiger Reserves (55+) · CITES Appendices · GBF 30×30 (COP-15 Kunming-Montreal 2022) · BBNJ 2023.
Mains GS-1 & GS-3: "Explain the factors responsible for high biodiversity in Western Ghats" · "Discuss the significance of coral reefs and threats to them" · "Critically evaluate India's in-situ conservation network" · "Examine the Kunming-Montreal Global Biodiversity Framework" · "Project Tiger at 50 — successes and gaps" · "Mangroves as ecological infrastructure" — heavy recurring zone.
Contents
- Biosphere & biomes (Fig 14.1)
- Ecosystem — structure, energy flow (Fig 14.2)
- Biogeochemical cycles (Fig 14.3)
- Ecological succession
- Marine ecosystems & pelagic zones (Fig 14.4)
- Biodiversity & 36 hotspots (Fig 14.5)
- India — 10 biogeographic zones (Fig 14.6)
- IUCN Red List & key species
- Conservation architecture in India
- Global conventions — CBD · CITES · Ramsar · GBF
- PYQs (Prelims + Mains, separate)
- Revision — 15 key facts
1 · Biosphere & biomes of the world
NCERT XI · Fundamentals of Physical Geography · Ch 15 (Life on the Earth) + Ch 16 (Biodiversity & Conservation) + NCERT XII · Biology · Unit 10 (Ecology)The biosphere is the thin zone around Earth's surface where life exists — it sits at the intersection of lithosphere (rock), hydrosphere (water) and atmosphere (air). Vertical reach: from ~10 km up (microbes in the upper troposphere) to ~11 km down (Mariana Trench microbes) — total span ~21 km, yet most life is concentrated in a much thinner band from sea floor to canopy top.
A biome is a large geographical region with a distinctive climate (esp. temperature + precipitation) and a characteristic community of plants & animals adapted to it. Climate (Köppen) → vegetation (biome) → fauna is the chain. The world has 10 major terrestrial biomes, plus aquatic biomes (freshwater + marine).
| Biome | Climate (Köppen) | Rain (mm/yr) | Dominant flora | Iconic fauna |
|---|---|---|---|---|
| Tropical rainforest | Af | > 2 000 (year-round) | Multi-layered evergreens, lianas, epiphytes | Jaguar, orang-utan, harpy eagle |
| Tropical seasonal / deciduous | Aw, Am | 1 000-2 000 | Sal, teak — drop leaves in dry season | Tiger, elephant, chital |
| Savanna grassland | Aw | 500-1 500 (wet/dry alternation) | Tall grasses + scattered acacia/baobab | Lion, zebra, wildebeest |
| Hot desert | BWh | < 250 | Cacti, succulents, xerophytes | Camel, fennec fox, addax |
| Mediterranean (chaparral) | Cs | 300-900 (winter rain) | Olive, cork oak, sclerophylls | Quail, wildcat |
| Temperate grassland (steppe/pampas/veld) | BSk | 250-750 | Short and tall grasses, no trees | Bison, pronghorn, saiga |
| Temperate deciduous forest | Cfb, Dfb | 750-1 500 | Oak, beech, maple — autumn leaf-fall | Brown bear, deer, wolf |
| Taiga / boreal coniferous | Dfc | 300-900 (snow) | Pine, spruce, fir, larch | Moose, lynx, brown bear |
| Tundra (arctic + alpine) | ET | < 250 | Mosses, lichens, dwarf willow; no trees | Reindeer, arctic fox, polar bear |
| Mountain (altitudinal zonation) | H (Trewartha) | variable | Belt sequence ≈ latitudinal sequence | Snow leopard, yak, ibex |
Latitude ≈ altitude: climbing 1 000 m up is roughly the same as moving ~1 000 km poleward — both drop T by ~6.5 °C. So a Himalayan slope mirrors the latitudinal biome belt from tropics to tundra in just a few km of climb.
Two index biomes — closer look
- Tropical rainforest — ~6 % of land but ~50 % of all terrestrial species. Four strata: emergent (~40 m) → canopy (25-40 m) → understorey → forest floor. Cycles ~75 % of moisture internally (evapotranspiration). Key examples — Amazon, Congo, SE Asia (Indonesia, Borneo, NE India). Threats — deforestation (Brazil lost ~17 % of Amazon since 1970).
- Taiga (boreal) — largest land biome by area (~17 M km², ~11 %); circumpolar, mostly Russia + Canada + Scandinavia. Stores ~30 % of global terrestrial carbon. Threats — warming 2-3× global mean → permafrost thaw → "zombie" CO₂/CH₄ release.
2 · Ecosystem — structure, function, energy flow
An ecosystem (A. G. Tansley, 1935) is a self-sustaining functional unit of the biosphere — biotic community + abiotic environment interacting through energy flow + nutrient cycling.
Structure — two components
- Abiotic — sunlight, temperature, water, soil, gases, minerals.
- Biotic — producers (autotrophs) · consumers (heterotrophs) · decomposers (detritivores, saprotrophs). Consumers split into primary (herbivores), secondary, tertiary, top carnivores.
Function — five processes
- Productivity — rate of biomass production. GPP = gross primary productivity; NPP = GPP − R (respiration). NPP is what's available to next trophic level.
- Decomposition — fragmentation → leaching → catabolism → humification → mineralisation. Done by saprotrophs + soil fauna.
- Energy flow — sun → producer → herbivore → carnivore → top carnivore → decomposers.
- Nutrient cycling — gaseous (C, N, O) + sedimentary (P, S).
- Homeostasis & succession — self-regulation + directional change to climax.
Energy flow & the 10 % rule
Energy enters as solar radiation (~50 % of incoming reaches plants; only ~1-5 % is captured by photosynthesis as GPP). At each trophic transfer, ~90 % of energy is lost as metabolic heat (respiration) + unconsumed parts. Only ~10 % moves up to the next level — Raymond Lindeman, 1942's "10 % law".
Consequence — food chains rarely have more than 4-5 trophic levels; biomass / numbers / energy taper as a pyramid.
- Pyramid of numbers — usually upright (grassland), can be inverted (single tree → many caterpillars → fewer birds).
- Pyramid of biomass — usually upright on land; INVERTED in oceans (zooplankton biomass > phytoplankton biomass at any instant, because phytoplankton turn over rapidly).
- Pyramid of energy — ALWAYS upright (10 % rule guarantees).
3 · Biogeochemical cycles
Nutrients move in cycles between biotic & abiotic pools. Two types — gaseous (reservoir = atmosphere / ocean → C, N, O) and sedimentary (reservoir = lithosphere → P, S, Ca).
3.1 Carbon cycle
Atmospheric CO₂ ≈ 422 ppm (2024, NOAA Mauna Loa) — up from 280 ppm pre-industrial. Pools (Pg C ≈ Gt C):
- Oceans ~38 000 Pg (largest mobile) · Soil + permafrost ~2 300 Pg · Atmosphere ~875 Pg · Vegetation ~550 Pg.
- Anthropogenic emissions ~10 Pg C/yr (fossil 9.4 + land-use 1.0); ocean uptake ~2.8 Pg; land uptake ~3.4 Pg; atmospheric increase ~5 Pg.
- Slow geological cycle — weathering of silicates removes CO₂ over million-year timescales; volcanism returns it.
3.2 Nitrogen cycle (gist)
Atmosphere is 78 % N₂ but inert. Five processes:
- Fixation — N₂ → NH₃ via Rhizobium, Azotobacter, cyanobacteria; lightning; industrial Haber-Bosch (1909, ~50 % of fixed N today).
- Nitrification — NH₃ → NO₂⁻ (Nitrosomonas) → NO₃⁻ (Nitrobacter).
- Assimilation — plants take up NO₃⁻ / NH₄⁺.
- Ammonification — decomposers convert organic N → NH₃.
- Denitrification — anaerobes Pseudomonas, Thiobacillus reduce NO₃⁻ → N₂, closing loop.
Excess reactive N → eutrophication, dead zones, NOₓ pollution; India is the world's 2nd-largest fertiliser N user.
3.3 Phosphorus, sulphur, hydrological cycles (one-liners)
- Phosphorus — purely sedimentary; no atmospheric step. Bottleneck for crop yields → Morocco controls ~70 % world rock-phosphate reserves.
- Sulphur — gaseous (SO₂, DMS, H₂S) + sedimentary (gypsum). Drives acid rain.
- Hydrological cycle — evap-condense-precip; redistributes ~500 000 km³/yr; covered in Topic 10.
4 · Ecological succession
Succession = directional, predictable change in community composition over time, ending in a climax equilibrium with regional climate (Clements 1916, monoclimax; Whittaker, polyclimax).
| Type | Trigger | Sequence | Time-scale |
|---|---|---|---|
| Primary | Bare rock — no prior community (lava, glacial moraine) | Lichen → moss → herbs → grass → shrub → trees | ~1 000 yr |
| Secondary | Disturbance (fire, abandoned field, flood) — soil intact | Annual herbs → perennials → shrubs → trees | ~100 yr (faster) |
| Hydrosere | Open pond | Phytoplankton → submerged → floating → reed-swamp → marsh meadow → woodland | ~500 yr |
| Xerosere | Dry rock / desert | Crustose lichen → foliose → moss → herb → grass → shrub → forest | ~1 000 yr |
| Halosere | Salty estuary | Algae → cordgrass/marsh → saltmarsh forest / mangrove | ~200 yr |
- Pioneer species — first to colonise (lichens, mosses).
- Sere — intermediate stage. Seral community — community at each stage.
- Climax — stable end community; for moist tropics = rainforest; for Indian monsoon plains = tropical deciduous (sal/teak).
- Modern view (Tansley + Whittaker) — climax is dynamic, not eternal; disturbance keeps community in patches at different seral stages.
Ecotone & edge effect: Ecotone = transition zone between two biomes (e.g., grassland-forest fringe). It has the highest species richness ("edge effect") because of overlap + unique fringe species (like the keystone tiger in the rainforest-grassland edge).
5 · Marine ecosystems & pelagic depth zones
Marine biomes occupy 71 % of Earth and produce ~50 % of atmospheric O₂. Two ways to slice them:
- By depth — 5 pelagic zones (water column) + 5 benthic zones (sea floor).
- By coastal type — estuary, mangrove, salt-marsh, coral reef, kelp forest, hydrothermal vent.
5.1 Pelagic depth zones (the water column)
| Zone | Depth (m) | Light | Indicator life |
|---|---|---|---|
| Epipelagic / sunlit / photic | 0-200 | full | Phytoplankton, tuna, dolphins, sharks, ~90 % marine life |
| Mesopelagic / twilight / dysphotic | 200-1 000 | dim | Lanternfish, squid, bioluminescent |
| Bathypelagic / midnight / aphotic | 1 000-4 000 | none | Anglerfish, gulper eel |
| Abyssopelagic / abyssal | 4 000-6 000 | none | Tripod fish, isopods; nodules |
| Hadalpelagic (trenches) | 6 000-11 000 | none | Amphipods, hadal snailfish (Mariana) |
5.2 Coastal & special marine ecosystems
| Ecosystem | Setting | Productivity | India example |
|---|---|---|---|
| Estuary | River mouth (brackish, tidal) | Very high — nutrient trap | Hooghly · Krishna · Godavari · Narmada |
| Mangrove | Intertidal tropical coasts | 2 000-2 500 g C/m²/yr (high) | Sundarbans · Bhitarkanika · Pichavaram |
| Salt marsh | Temperate intertidal | Very high | Gulf of Kutch (only major Indian salt-marsh) |
| Coral reef | Tropical shelf, 0-30 m, 23-29 °C, salinity 32-42 ‰ | ~2 500 g C/m²/yr — "rainforests of the sea" | Gulf of Mannar · Gulf of Kutch · A&N · Lakshadweep |
| Kelp forest | Temperate rocky coasts, < 20 °C | Very high; not native to India | (absent from Indian waters — too warm) |
| Hydrothermal vent | Mid-ocean ridges, 2 000+ m | Chemosynthetic (no sunlight) — tube worms, vent crabs, archaea | Central Indian Ridge — India holds SMS exploration block |
| Seagrass meadow | Shallow soft-bottom (often near coral) | ~1 200 g C/m²/yr — blue carbon | Palk Bay · Gulf of Mannar (dugong habitat) |
Coral reefs — quick UPSC facts
- Three reef types (Darwin 1842 subsidence theory): fringing → barrier → atoll. Lakshadweep = atolls (only set in India). Andaman = fringing + barrier. Great Barrier Reef (Australia) = world's largest, 2 300 km.
- Coral = animal (cnidarian polyp) + symbiotic algae Zooxanthellae providing colour + ~90 % nutrition.
- Bleaching — heat-stressed coral expels zooxanthellae → turns white → starves. Mass bleaching events: 1998 · 2010 · 2014-17 · 2023-24 (4th global event, NOAA + ICRI April 2024, > 60 % of reefs affected).
- IPCC AR6 — 70-90 % of corals lost at 1.5 °C, > 99 % at 2 °C.
6 · Biodiversity & 36 global hotspots
Biodiversity = variety of life at three levels — genetic (within species), species (between species), ecosystem (across biomes). Convention term coined by E. O. Wilson, 1986. Earth: ~2.16 million described species (Catalogue of Life 2024) out of estimated 8.7 million.
India: ~1.04 lakh fauna + 55 000 flora = ~8 % of world species on just 2.4 % of land. Mega-diverse country (17 listed by UNEP-WCMC, accounting for > 70 % of world species).
Biodiversity hotspot — definition (Norman Myers 1988; CI 1999)
A region must satisfy two strict criteria:
- Have at least 1 500 endemic vascular plant species (≥ 0.5 % world total).
- Have lost ≥ 70 % of its primary vegetation.
Conservation International currently lists 36 hotspots — only 2.4 % of land but home to ~50 % of all endemic plants and ~43 % of endemic vertebrates. India fully or partly contains 4:
| # | Hotspot | India footprint | Key endemics |
|---|---|---|---|
| 1 | Himalaya | Northern + NE India, Nepal, Bhutan, parts of China & Myanmar | Snow leopard, red panda, Himalayan tahr, blue poppy |
| 2 | Indo-Burma | NE India (except Assam plains), Myanmar, Thailand, Cambodia, Laos, Vietnam, S. China | Hoolock gibbon, white-winged duck, Mekong giant catfish |
| 3 | Western Ghats & Sri Lanka | W. coast of India (Tapi-Kanyakumari), SL | Lion-tailed macaque, Nilgiri tahr, purple frog, Malabar grey hornbill |
| 4 | Sundaland | Nicobar islands (only Indian part); Indonesia, Malaysia, Brunei, S. Thailand | Nicobar megapode, orang-utan, Sumatran rhinoceros |
Hotspot ≠ Megadiverse country. Hotspots are regions (CI). Megadiverse countries are nations (UNEP-WCMC, 17 listed). India is BOTH.
7 · India — 10 biogeographic zones (Rodgers & Panwar 1988)
Rodgers, Panwar & Mathur 1988/2002 · Wildlife Institute of India · MoEFCCWII scientists W. A. Rodgers and H. S. Panwar (1988) divided India into 10 biogeographic zones and 27 biotic provinces — the official framework used in the Protected Area Network & National Wildlife Action Plan.
| # | Zone | % area | Key features |
|---|---|---|---|
| 1 | Trans-Himalaya | 5.7 | Ladakh, Spiti, N Sikkim. Cold desert. Snow leopard, black-necked crane, Tibetan antelope |
| 2 | Himalaya | 7.2 | Greater + Lesser + Outer Himalaya. Brown bear, musk deer, monal |
| 3 | Indian Desert | 6.9 | Thar (Rajasthan-Gujarat). GIB, chinkara, desert fox |
| 4 | Semi-Arid | 15.6 | Punjab plain, Gujarat-Rajwara, Rajasthan-Aravalli. Blackbuck, wolf, Asiatic lion (Gir) |
| 5 | Western Ghats | 5.8 | Sahyadri. Lion-tailed macaque, Nilgiri tahr, Malabar civet, purple frog |
| 6 | Deccan Peninsula | 42.0 | Largest zone. Central highlands, E. Plateau, Chhota Nagpur, Eastern Ghats. Tiger, sloth bear, wolf |
| 7 | Gangetic Plain | 10.8 | Alluvium. Gangetic dolphin, gharial, hog deer, swamp deer |
| 8 | Coasts | 2.5 | Mainland coast incl. estuaries. Olive ridley, dugong (Palk Bay), saltwater croc |
| 9 | North-East | 5.2 | Brahmaputra + Barak valleys, Hills. Hoolock gibbon, hispid hare, pygmy hog, one-horned rhino |
| 10 | Islands | 0.3 | A&N + Lakshadweep. Nicobar megapode, dugong, Andaman wild pig |
Mnemonic for 10 zones in order: "Trans-Hi · Hi · Desert · Semi · W.Ghats · Deccan · Gangetic · Coast · NE · Islands" — recite north → south then peripheral.
8 · IUCN Red List & key Indian species
IUCN — International Union for Conservation of Nature (1948, Fontainebleau; HQ Gland, Switzerland) maintains the Red List of Threatened Species since 1964. India hosts ~12 % of all IUCN-assessed species.
9 Red List categories (memorise order)
- EX — Extinct (e.g., dodo, Indian cheetah 1952)
- EW — Extinct in the Wild (only in captivity / ex-situ)
- CR — Critically Endangered (e.g., gharial, GIB, hangul, pygmy hog)
- EN — Endangered (e.g., Asiatic lion, tiger, snow leopard, red panda, one-horned rhino, lion-tailed macaque)
- VU — Vulnerable (e.g., Indian elephant, sloth bear, dugong, Nilgiri tahr)
- NT — Near Threatened
- LC — Least Concern
- DD — Data Deficient
- NE — Not Evaluated
Threatened ≡ CR + EN + VU (the 3 "at-risk" categories).
Special species categories (frequent UPSC trick)
| Category | Definition | Examples |
|---|---|---|
| Keystone | Disproportionately large effect on ecosystem; removal collapses structure | Sea otter (kelp), tiger (forest cascade), fig trees (rainforest) |
| Umbrella | Wide-ranging — protecting it protects many other species sharing habitat | Tiger, elephant, snow leopard |
| Flagship | Charismatic, used to galvanise public conservation support | Tiger (India), panda (China), polar bear (Arctic) |
| Indicator | Sensitive to ecosystem stress; its status reveals environmental quality | Frogs (water pollution), lichens (air pollution) |
| Endemic | Found only in a specific geographic area | Lion-tailed macaque (W. Ghats), purple frog |
India-specific landmark species & latest counts
- Tiger (Panthera tigris) — EN; India ~3 682 (NTCA 2022, ~75 % of world tiger population); 57 Tiger Reserves (Dholpur-Karauli, Rajasthan added 2024).
- Asiatic lion (Panthera leo persica) — EN; Gir + Greater Gir ~891 (Census 2025); only wild population in the world.
- Indian one-horned rhino — VU; ~4 014 (DNA-based 2022); Kaziranga, Pobitora, Manas, Orang, Jaldapara, Dudhwa.
- Indian elephant — EN (IUCN reclassified 2020); India ~29 964 (2017 census); 33 Elephant Reserves; PMM3 fresh census ongoing 2025.
- Snow leopard — VU; SPAI 2024 estimate ~718; ranges Ladakh, J&K, HP, Uttarakhand, Sikkim, Arunachal.
- Cheetah — EX in India 1952; Project Cheetah 17 Sept 2022 reintroduced 8 Namibian + 12 S. African cheetahs to Kuno NP (MP).
- Great Indian Bustard (GIB) — CR; ~150 left, mostly Desert NP, Rajasthan; threatened by power-line strikes (SC 2024 directive on undergrounding).
- Gangetic river dolphin — EN; "National Aquatic Animal" (2009); Project Dolphin 2020; ~4 067 as per 2024 census.
- Gharial — CR; National Chambal Sanctuary, Katarniaghat.
- Hangul (Kashmir stag) — CR; State animal J&K; Dachigam NP.
9 · Conservation architecture in India
NCERT Class 11 — India: Physical Environment, Ch. 5; Class 12 Biology, Ch. 15; MoEFCC Annual Report 2024-25.
9.1 In-situ vs Ex-situ — the two pillars
| Mode | Where species is conserved | Examples |
|---|---|---|
| In-situ | In the natural habitat — protected area network, sacred groves, reserved forests | National Parks · Wildlife Sanctuaries · Biosphere Reserves · Tiger Reserves · Conservation & Community Reserves · Ramsar wetlands · Sacred Groves (Kavu in Kerala, Devarakadu in Karnataka, Orans in Rajasthan) |
| Ex-situ | Outside the natural habitat — captive facilities, gene banks, seed banks, cryopreservation | Zoological parks (164 recognised by Central Zoo Authority) · Botanical gardens (NBRI Lucknow, IBG Howrah) · Seed banks (NBPGR Delhi) · NBFGR (fish), NBAGR (animal), NBAIR (insect) gene-bank network · Conservation breeding (gharial, vulture — Pinjore, Rani; cheetah — Kuno) |
9.2 Protected Area Network (PAN) — five categories
Defined under the Wild Life (Protection) Act 1972 (WPA). Latest count (MoEFCC, 2025): 1 014 protected areas covering ~5.32 % of India's land.
| Category | Count (2025) | Legal basis (WPA) | Key features |
|---|---|---|---|
| National Park (NP) | 106 | Sec 35 | Strict protection; no human activity, no grazing; boundaries fixed by notification; first — Hailey/Corbett NP (1936); largest — Hemis (Ladakh) |
| Wildlife Sanctuary (WLS) | 573 | Sec 18 | Limited human activity allowed (collection of minor produce, grazing) at CWLW's discretion; can be upgraded to NP |
| Conservation Reserve | 123 | Sec 36A (2002 amendment) | Owned by govt; corridor / buffer between PAs; managed by Conservation Reserve Management Committee |
| Community Reserve | 220 | Sec 36C (2002 amendment) | On community or private land; voluntary participation; Community Reserve Management Committee runs it |
| Tiger Reserve (TR) | 58 | Sec 38V (2006 amendment) | Overlay on NP/WLS; declared by NTCA; core (critical tiger habitat) + buffer; latest — Dholpur-Karauli (Raj, 2023), Veerangana Durgavati (MP, 2023), Ratapani (MP, 2024), Madhav (MP, 2025) |
9.3 Biosphere Reserves (BR) — UNESCO MAB programme
Three-zone model: Core (legally protected) → Buffer (research, tourism) → Transition (sustainable use, settlements). India has 18 BRs, of which 12 are on UNESCO's World Network of Biosphere Reserves (WNBR).
| # | Biosphere Reserve | State(s) | Year designated | WNBR? |
|---|---|---|---|---|
| 1 | Nilgiri | TN-KL-KA | 1986 (1st) | 2000 |
| 2 | Nanda Devi | Uttarakhand | 1988 | 2004 |
| 3 | Nokrek | Meghalaya | 1988 | 2009 |
| 4 | Great Nicobar | A&N | 1989 | 2013 |
| 5 | Gulf of Mannar | Tamil Nadu | 1989 | 2001 |
| 6 | Manas | Assam | 1989 | — |
| 7 | Sundarbans | West Bengal | 1989 | 2001 |
| 8 | Simlipal | Odisha | 1994 | 2009 |
| 9 | Dibru-Saikhowa | Assam | 1997 | — |
| 10 | Dehang-Debang | Arunachal | 1998 | — |
| 11 | Pachmarhi | Madhya Pradesh | 1999 | 2009 |
| 12 | Khangchendzonga | Sikkim | 2000 | 2018 |
| 13 | Agasthyamalai | KL-TN | 2001 | 2016 |
| 14 | Achanakmar-Amarkantak | CG-MP | 2005 | 2012 |
| 15 | Kachchh (largest) | Gujarat | 2008 | — |
| 16 | Cold Desert | HP | 2009 | — |
| 17 | Seshachalam | AP | 2010 | — |
| 18 | Panna | MP | 2011 | 2020 |
9.4 Other in-situ designations
- Ramsar Sites (wetlands of international importance) — India ratified 1982; 89 sites covering 13.32 lakh ha (as of June 2025) — largest network in Asia. Largest: Sundarbans (WB, 4 230 km²). Newest cluster: Nanjarayan & Kazhuveli (TN, 2024).
- Important Bird & Biodiversity Areas (IBAs) — 554 sites (BNHS + BirdLife Intl.).
- Eco-Sensitive Zones (ESZ) — buffer of 1-10 km around NP/WLS under EPA 1986; SC 2022 mandated minimum 1 km (later modified 2023).
- Critical Wildlife Habitats (CWH) — under Forest Rights Act 2006; areas where rights holders are required to be resettled.
- Sacred Groves — estimated >1 00 000 in India; community-protected forest patches.
9.5 Flagship species-recovery projects — chronological
| Project | Launch | Lead agency | Status / key data 2025 |
|---|---|---|---|
| Project Tiger | 1 Apr 1973 (9 reserves: Corbett, Bandipur, Kanha, Manas, Melghat, Palamau, Ranthambhore, Similipal, Sundarbans) | NTCA (since 2006) under MoEFCC | 58 TRs · ~3 682 tigers (2022 census, 75 % of global) · M-STrIPES app · 4-yearly all-India estimation |
| Project Crocodile | 1975 (with UNDP/FAO) | MoEFCC | Three species: gharial, mugger, saltwater; gharial pop. recovered from ~200 (1975) to ~3 000 today |
| Project Elephant | 1992 | MoEFCC / Project Elephant Directorate | 33 Elephant Reserves; ~29 964 elephants (2017 census, fresh DNA-based census 2024-25); MIKE programme partner |
| Vulture Action Plan | 2006 (revised 2020-25) | MoEFCC + BNHS | Diclofenac ban (2006), meloxicam alternative; Jatayu breeding centres (Pinjore HR, Rani Assam, Rajabhatkhawa WB); 9 species incl. CR White-rumped, Slender-billed, Indian, Red-headed |
| Project Snow Leopard | 2009 | MoEFCC | 5 Himalayan states; SPAI estimate 718 (2024); GSLEP global partnership (12 range countries) |
| Project Dolphin | 15 Aug 2020 (announced); CCEA Oct 2024 (₹2 763 cr, 5 yr) | MoEFCC | Gangetic + Indus (riverine) + Indian Ocean (marine); ~4 067 river dolphins (2024 census) |
| Project Cheetah | 17 Sept 2022 | NTCA / MoEFCC | 20 cheetahs from Namibia & S. Africa to Kuno NP (MP); India-born cubs from 2023; Gandhi Sagar (MP) as 2nd site (2024) |
| Project Lion | 2020 announced · Project Lion launched 2024 (₹2 927 cr, 10 yr) | MoEFCC / Gujarat Forest Dept | Asiatic lion only in Gir-Greater Gir (Saurashtra); 891 lions (Census 2025, +29 % over 2020); Barda WLS as 2nd home |
9.6 Key institutions
- MoEFCC — Ministry of Environment, Forest & Climate Change (apex).
- NTCA — National Tiger Conservation Authority (statutory, 2006); chaired by MoEFCC Minister.
- NBA — National Biodiversity Authority (Chennai, 2003) under BD Act; SBBs + BMCs at state/local levels.
- CZA — Central Zoo Authority (statutory, 1992).
- WII — Wildlife Institute of India (Dehradun, 1982) — autonomous research body.
- WCCB — Wildlife Crime Control Bureau (2007, multi-disciplinary).
- ZSI (Zoological Survey of India, 1916) & BSI (Botanical Survey of India, 1890) — Kolkata-headquartered taxonomic authorities.
- FSI — Forest Survey of India (Dehradun, 1981) — biennial ISFR.
9.7 Legal framework — five pillars
| Act | Year | What it does |
|---|---|---|
| Indian Forest Act | 1927 | Three forest categories — Reserved, Protected, Village. Colonial-era, still backbone of forest law. |
| Wild Life (Protection) Act (WPA) | 1972 (amended 1982, 1986, 1991, 2002, 2006, 2022) | Constitutes PAs, NBWL, NTCA; bans hunting of protected species. 2022 amendment rationalised schedules — earlier 6 → now 4 schedules (I: animals with highest protection; II: animals with lesser protection; III: plants; IV: CITES-listed species); brought CITES into domestic law. |
| Forest (Conservation) Act | 1980 → renamed "Van (Sanrakshan Evam Samvardhan) Adhiniyam" by 2023 amendment | Central permission needed for diversion of forest land; 2023 amendment exempted forest land within 100 km of international borders & LWE-affected areas (challenged in SC). |
| Environment (Protection) Act | 1986 (post-Bhopal) | Umbrella law; basis for EIA Notification 2006, ESZ notifications, CRZ rules. |
| Biological Diversity Act | 2002 (amended 2023) | Three-tier — NBA (centre), SBB (state), BMC (local); regulates access & benefit-sharing (ABS). 2023 amendment: decriminalised offences, eased compliance for AYUSH/research, recognised codified traditional knowledge. |
| Scheduled Tribes & Other Traditional Forest Dwellers (Recognition of Forest Rights) Act (FRA) | 2006 | Vests individual + community forest rights; defines Critical Wildlife Habitats. |
10 · Global biodiversity conventions & frameworks
UNEP / CBD Secretariat factsheets; MoEFCC India BSAP 2024-30.
| Convention / Framework | Year · Host city | What it does | India |
|---|---|---|---|
| CITES — Convention on International Trade in Endangered Species | Signed Washington 1973, into force 1975 | Three appendices: App I — no commercial trade (~1 000 species: tiger, rhino, snow leopard, GIB); App II — regulated trade (~37 000 species); App III — listed by individual country. Secretariat: Geneva. CoP every 3 years. | Ratified 1976; nodal — MoEFCC; CoP19 Panama 2022, CoP20 Samarkand 2025 |
| Ramsar Convention — wetlands of international importance | Signed Ramsar (Iran) 1971, into force 1975 | Designation of "Ramsar Sites"; Montreux Record — list of sites under ecological threat needing priority action; Wise-use principle. Secretariat: Gland, Switzerland. World Wetlands Day: 2 Feb. | Ratified 1982; 89 sites, 13.32 lakh ha — largest Asian network. Montreux Record: Keoladeo (Raj, since 1990) & Loktak (Manipur, since 1993) — only Indian sites. Chilika removed 2002. |
| CMS / Bonn Convention — Conservation of Migratory Species | Signed Bonn 1979, into force 1983 | App I — endangered migratory species (strict protection); App II — species needing cooperative agreements (eg. Siberian crane MoU, dugong MoU, raptors MoU). | India hosted CMS CoP13 Gandhinagar Feb 2020 — adopted "Gandhinagar Declaration"; mascot Gibi the dolphin. Added 3 species at CoP13: Asian elephant, GIB, Bengal florican. |
| CBD — Convention on Biological Diversity | Adopted Rio Earth Summit June 1992, into force Dec 1993 | Three objectives: (i) conservation of biodiversity; (ii) sustainable use of components; (iii) fair & equitable sharing of benefits arising from genetic resources (ABS). Secretariat: Montreal. CoP every 2 years. USA has signed but not ratified — major exception. | Ratified 1994; gave rise to BD Act 2002 + NBA. India hosted CoP-11 Hyderabad 2012. |
| Cartagena Protocol on Biosafety (under CBD) | Adopted Montreal 2000, in force 2003 | Regulates trans-boundary movement of Living Modified Organisms (LMOs/GMOs); "Advance Informed Agreement" procedure. | Ratified 2003; nodal — MoEFCC; basis for GEAC clearance. |
| Nagoya Protocol on ABS (under CBD) | Adopted Nagoya, Japan 2010, in force 2014 | Operationalises CBD's 3rd objective — Access & Benefit Sharing of genetic resources & associated traditional knowledge. | Ratified Oct 2012; ABS rules notified 2014, revised 2024. |
| Nagoya–Kuala Lumpur Supplementary Protocol | 2010, in force 2018 | Liability & redress for damage from LMOs. | India: signatory. |
| Aichi Biodiversity Targets (CBD Strategic Plan 2011-20) | CoP-10 Nagoya 2010 | 20 targets under 5 Strategic Goals; deadline 2020 — NONE fully met globally (GBO-5, 2020). | India: 12 National Biodiversity Targets aligned. |
| Kunming-Montreal Global Biodiversity Framework (GBF) | CoP-15 (Part II), Montreal Dec 2022 | Successor to Aichi. 4 Goals (2050) + 23 Targets (2030). Flagship: Target 3 — "30×30" (protect 30 % land & sea by 2030). Targets 7 (halve pollution), 8 (climate action), 18 (eliminate harmful subsidies $500 bn/yr), 19 ($200 bn/yr biodiv finance incl. $30 bn from developed to developing). | India released updated NBSAP/BSAP 2024-30 aligned to GBF (CoP-16 Cali, Oct 2024). Pushed for separate Cali Fund; achieved DSI multilateral fund. |
| BBNJ Agreement — "High Seas Treaty" | UNGA, 19 June 2023; opens for signature 20 Sep 2023; needs 60 ratifications | Legally binding instrument under UNCLOS for conservation & sustainable use of marine biodiversity beyond national jurisdiction; MPAs on high seas, EIA, capacity building, MGRs & benefit sharing. | India signed 25 Sept 2024 (UNGA); ratification pending. |
| IPBES — Intergovernmental Science-Policy Platform on Biodiversity & Ecosystem Services | Established Panama 2012 | "IPCC for biodiversity"; Global Assessment 2019 — 1 million species at risk of extinction. Nexus Assessment 2024. | India: member; nodal — MoEFCC. |
| IUCN — International Union for Conservation of Nature | Founded 1948 Fontainebleau (oldest); HQ Gland | Maintains the Red List (9 categories), Green Status, Protected Planet. World Conservation Congress every 4 yrs. | India: state member; MoEFCC nodal. |
| UNFF — UN Forum on Forests & UN-REDD+ | UNFF 2000; REDD+ Warsaw Framework 2013 | Forest-based mitigation; performance-based payments for reduced deforestation. India's "REDD+ National Strategy" 2018. | India: among top 3 in forest-cover gain (2010-20 FRA). |
- CBD (1992) — biodiversity umbrella · CITES (1973) — trade in endangered species · CMS (1979) — migratory species · Ramsar (1971) — wetlands. (Different conventions, different secretariats.)
- Cartagena = biosafety (LMOs) · Nagoya = ABS · both are protocols under CBD, not standalone treaties.
- Aichi Targets (2011-20) → Kunming-Montreal GBF (2021-30). Don't write "Aichi" for current targets.
- "30×30" is Target 3 of GBF, not a UNFCCC or Ramsar target.
- Montreux Record ≠ Montreal Protocol. Former is Ramsar's wetland alert list; latter (1987) is the ozone-protection treaty.
11 · Previous-Year Questions (PYQs) — Prelims & Mains, strictly separate
Compiled from UPSC CSE Prelims (2011-2024) & CSE Mains (2013-2024). Authentic UPSC questions kept separate from practice questions.
A · Prelims — Direct UPSC questions
Verbatim or near-verbatim from official UPSC question papers.
Q. Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?
(a) Oceans → lakes → grasslands → mangroves
(b) Mangroves → oceans → grasslands → lakes
(c) Mangroves → grasslands → lakes → oceans
(d) Oceans → mangroves → lakes → grasslands
Answer: (c). Coastal/estuarine mangroves & coral reefs are among the most productive (NPP > 2 000 g/m²/yr); open oceans are deserts of the sea (~125 g/m²/yr).
Q. Consider the following statements: (1) Some mushrooms have medicinal properties. (2) Some species of mushroom have anti-cancer properties. (3) Some mushrooms have hallucinogenic properties. Which of the statements given above are correct?
Answer: (d) 1, 2 and 3. (Tested ecology/fungi knowledge — straight from NCERT Biology.)
Q. Consider the following: (1) Aerosols (2) Foam agents (3) Fire retardants (4) Lubricants — In the making of how many of the above are hydrofluorocarbons (HFCs) used?
Answer: Three (1, 2, 3). Linked to Kigali Amendment 2016 to Montreal Protocol — UPSC routinely mixes ozone/biodiv conventions.
Q. "If a particular plant species is placed under Schedule VI of The Wildlife Protection Act, 1972, what is the implication?"
(a) Cultivation prohibited
(b) Export prohibited
(c) Both (a) and (b)
(d) Cultivation/collection regulated
Answer (as per 2022 key): (c). Caveat: The WPA 2022 Amendment rationalised schedules from 6 to 4 — plants are now under Schedule III; the implication (no cultivation/export without permission) is the same.
Q. Consider the following statements about the Kalakkad-Mundanthurai Tiger Reserve: (1) It is located on the southernmost tip of the Western Ghats. (2) It is in Tamil Nadu. (3) It overlaps with Agasthyamalai Biosphere Reserve. Which are correct?
Answer: (d) All three. KMTR is the southernmost tiger reserve, in TN, overlapping with Agasthyamalai BR (designated 2001, WNBR 2016).
Q. Consider the following statements about the Eco-Sensitive Zones (ESZs): (1) ESZs are notified by MoEFCC. (2) Their boundaries are fixed and cannot be revised. (3) Within ESZ industries causing pollution are strictly prohibited. Which are correct?
Answer: (b) 1 and 3 only. ESZs are notified under EPA 1986; boundaries can be revised on review. Polluting industries are prohibited; mining is regulated (SC 2018 KS Variava).
Q. With reference to "Trade-Related Analysis of Fauna and Flora in Commerce" (TRAFFIC), which of the following statements is/are correct? (1) TRAFFIC is a bureau under the United Nations Environment Programme (UNEP). (2) Its mission is to ensure that the trade in wild plants and animals is not a threat to nature.
Answer: (b) 2 only. TRAFFIC is a joint programme of WWF + IUCN, NOT a UN body.
Q. Which of the following are in the Government of India's "Seven Mega Missions" for biodiversity conservation in the country? Consider: Project Tiger · Project Elephant · Project Snow Leopard · Project Dolphin · Crocodile Conservation Project — and identify mismatches.
Note: UPSC has repeatedly tested chronology — Tiger (1973) · Crocodile (1975) · Elephant (1992) · Snow Leopard (2009) · Dolphin (2020) · Cheetah (2022) · Lion (2024). Memorise this sequence.
Q. Consider the following statements: (1) Under Ramsar Convention, it is mandatory on the part of the Government of India to protect & conserve all wetlands in the territory of India. (2) Wetlands (Conservation & Management) Rules, 2010 were framed by the Government of India based on recommendations of Ramsar Convention. (3) Wetlands (Conservation & Management) Rules, 2010 also encompass the drainage area or catchment regions of the wetlands as determined by authority. Which are correct?
Answer: (b) 2 and 3 only. Ramsar only obliges protection of designated Ramsar sites, not all wetlands.
Q. Why is a plant called Prosopis juliflora often mentioned in news? It is — (a) a fast-growing leguminous shrub for fodder; (b) the cause of soil salinity in dryland agriculture; (c) listed as an invasive species threatening native vegetation; (d) tolerant to drought.
Answer: (c). Prosopis juliflora (vilayati babool) — listed by IUCN as one of the world's 100 worst invasive species; spread across Aravalli & Banni grasslands.
Q. Consider the following statements: (1) The definition of "Critical Wildlife Habitat" (CWH) is found in the Forest Rights Act, 2006. (2) For declaring CWH, the Indian Forest Act, 1927 is invoked. (3) The "right to manage" CWH lies with the Environment Ministry. Which are correct?
Answer: (a) 1 only. CWH is defined under FRA 2006 §2(b); declared by MoEFCC after expert committee + Gram Sabha consultation; protected under WPA 1972, not IFA 1927.
Q. The term "M-STrIPES" is sometimes seen in the news in the context of — (a) captive breeding of wild fauna; (b) maintenance of tiger reserves; (c) indigenous personnel for vigilance against ecological offences; (d) lions in Gir.
Answer: (b). M-STrIPES (Monitoring System for Tigers — Intensive Protection & Ecological Status) — Android-based patrol monitoring used by NTCA across all tiger reserves.
Q. "Vidyanjali Yojana" — incorrect distractor. Among the following biodiversity-related, which one is supported by "United Nations Decade on Ecosystem Restoration"? (Years 2021-2030)
Answer: All restoration efforts — Bonn Challenge, GBF, India's Aravalli Green Wall, MISHTI mangroves.
Q. In which of the following States is Pakhui Wildlife Sanctuary located? (a) Arunachal Pradesh (b) Manipur (c) Meghalaya (d) Nagaland
Answer: (a) Pakke (Pakhui) Tiger Reserve — Arunachal Pradesh; famous hornbill habitat.
Q. If you walk through the countryside, you may notice many Areca palm trees in plantations of Kerala. What is the use of the spadix of Areca palm? It is — used in religious rites & rituals.
Note: Tests Western Ghats agro-biodiversity. UPSC PYQs repeatedly link biodiversity to ethnobotany.
Q. The "Red Data Books" published by the IUCN contain lists of — (1) Endemic plant & animal species in biodiversity hotspots. (2) Threatened plant & animal species. (3) Protected sites for conservation of nature & natural habitats. Select the correct.
Answer: (b) 2 only. IUCN Red List documents threatened species — across 9 categories from EX to LC.
Q. Consider the following pairs: 1. Dampa Tiger Reserve — Mizoram · 2. Gumti Wildlife Sanctuary — Sikkim · 3. Saramati Peak — Nagaland. Which are correctly matched?
Answer: (c) 1 and 3 only. Gumti WLS is in Tripura, not Sikkim.
Q. Lichens, which are capable of initiating ecological succession even on a bare rock, are a symbiotic association of — (a) algae & bacteria (b) algae & fungi (c) bacteria & fungi (d) fungi & mosses.
Answer: (b). Lichens are the classic pioneer community of xerosere (lithosere) succession.
Q. Biodiversity forms the basis for human existence in the following ways: (1) Soil formation (2) Prevention of soil erosion (3) Recycling of waste (4) Pollination of crops. Select the correct.
Answer: (d) 1, 2, 3 and 4 — all are ecosystem services.
Q. A sandy & saline area is the natural habitat of an Indian animal species. The animal has no predators in that area, but its existence is threatened due to encroachment by humans. Which is the animal?
Answer: (b) Indian Wild Ass (Khur) — Rann of Kachchh; sole population in Wild Ass Sanctuary, Gujarat.
Practice Prelims — topic-aligned (one-liners)
Q. Who coined the term "ecosystem"? (a) Haeckel 1866 (b) Tansley 1935 (c) Lindeman 1942 (d) Odum 1953
Answer: (b) Arthur Tansley, 1935.
Q. The "10 % Law" of energy transfer was proposed by? (a) Tansley (b) Lindeman (c) Odum (d) Elton
Answer: (b) Raymond Lindeman, 1942.
Q. How many global biodiversity hotspots are recognised by Conservation International? (a) 25 (b) 34 (c) 36 (d) 50
Answer: (c) 36 (latest: NA Coastal Plain, 2016).
Q. Which is NOT among India's four biodiversity hotspots? (a) Himalaya (b) Indo-Burma (c) Western Ghats-Sri Lanka (d) Eastern Himalaya as separate hotspot
Answer: (d). Eastern Himalaya is part of the Himalaya hotspot. India's four are Himalaya, Indo-Burma, W. Ghats-Sri Lanka, Sundaland.
Q. Rodgers & Panwar (1988) divided India into how many biogeographic zones? (a) 8 (b) 9 (c) 10 (d) 12
Answer: (c) 10.
Q. Correct sequence of IUCN Red List categories (most to least threatened)? (a) EX → EW → CR → EN → VU → NT → LC (b) EX → CR → EN → VU → NT → LC → EW (c) CR → EX → EW → EN → VU → NT → LC (d) EX → CR → EW → EN → VU → LC → NT
Answer: (a). Full 9: EX, EW, CR, EN, VU, NT, LC, DD, NE.
Q. Project Tiger launched on? (a) 1 Apr 1972 (b) 1 Apr 1973 (c) 1 Apr 1974 (d) 1 Apr 1975
Answer: (b) 1 April 1973 from Corbett.
Q. Number of Tiger Reserves in India (2025)? (a) 50 (b) 54 (c) 58 (d) 62
Answer: (c) 58 (Madhav, MP — 58th, 2025).
Q. India's tiger population as per 2022 NTCA census? (a) ~2 967 (b) ~3 167 (c) ~3 682 (d) ~4 200
Answer: (c) 3 682 — ~75 % of global tigers.
Q. Asiatic lion population (Census 2025)? (a) 674 (b) 758 (c) 891 (d) 1 020
Answer: (c) 891 — Gir & Greater Gir.
Q. India's first Biosphere Reserve (1986)? (a) Nanda Devi (b) Nilgiri (c) Sundarbans (d) Nokrek
Answer: (b) Nilgiri.
Q. India has 18 Biosphere Reserves; how many are on UNESCO's WNBR? (a) 9 (b) 10 (c) 12 (d) 15
Answer: (c) 12.
Q. India's Ramsar Site count (June 2025)? (a) 75 (b) 80 (c) 85 (d) 89
Answer: (d) 89 — largest network in Asia.
Q. Which two Indian Ramsar sites are on the Montreux Record? (a) Chilika & Loktak (b) Keoladeo & Loktak (c) Wular & Keoladeo (d) Sundarbans & Vembanad
Answer: (b) Keoladeo (since 1990) & Loktak (since 1993). Chilika was removed in 2002.
Q. CITES has how many Appendices? (a) 2 (b) 3 (c) 4 (d) 5
Answer: (b) Three — App I (no trade), App II (regulated), App III (country-listed).
Q. Kunming-Montreal Global Biodiversity Framework was adopted at? (a) CoP-14 Sharm El-Sheikh 2018 (b) CoP-15 Montreal Dec 2022 (c) CoP-16 Cali 2024 (d) CoP-13 Cancun 2016
Answer: (b) CoP-15 Part II, Montreal, Dec 2022.
Q. Target 3 of the GBF — "30×30" — refers to? (a) 30 % afforestation by 2030 (b) Conserve 30 % of land & sea by 2030 (c) 30 % climate finance to biodiversity by 2030 (d) 30 % cut in pesticide use by 2030
Answer: (b).
Q. Project Cheetah reintroduced cheetahs to which national park? (a) Kuno NP, MP (b) Mukundra Hills, Raj (c) Gandhi Sagar, MP (d) Nauradehi, MP
Answer: (a) Kuno NP, Madhya Pradesh — 17 Sept 2022. Gandhi Sagar is the 2nd site (2024).
Q. WPA 1972 — after 2022 amendment, how many schedules? (a) 4 (b) 5 (c) 6 (d) 7
Answer: (a) 4 — rationalised from earlier 6.
Q. The National Biodiversity Authority is headquartered at? (a) New Delhi (b) Dehradun (c) Chennai (d) Hyderabad
Answer: (c) Chennai (est. 2003).
Q. Nagoya Protocol deals with? (a) Biosafety of GMOs (b) Access & Benefit Sharing (c) Wetland conservation (d) Migratory species
Answer: (b) ABS — operationalises 3rd objective of CBD; adopted 2010, in force 2014.
Q. BBNJ Agreement (2023) governs? (a) Trade in endangered species (b) High-seas biodiversity beyond national jurisdiction (c) Land degradation neutrality (d) Mountain ecosystems
Answer: (b) High Seas Treaty under UNCLOS.
Q. Largest mammal in the Sundarbans Tiger Reserve, second only to the tiger in conservation focus, is? (a) Asian elephant (b) Gangetic dolphin (c) Estuarine crocodile (d) Wild boar
Answer: (c) Saltwater/estuarine crocodile (Crocodylus porosus) — Schedule I.
Q. Which Indian state has the highest number of Tiger Reserves? (a) Karnataka (b) Madhya Pradesh (c) Maharashtra (d) Uttarakhand
Answer: (b) Madhya Pradesh — 9 TRs ("Tiger State of India").
Q. "GBF Target 18" calls for elimination/reform of harmful subsidies of at least? (a) $100 bn/yr (b) $200 bn/yr (c) $500 bn/yr (d) $1 trillion/yr
Answer: (c) $500 bn/yr by 2030.
B · Mains — Direct UPSC questions
From CSE Mains General Studies Paper 1 (Geography) and Paper 3 (Environment).
Q. "Discuss the merits and demerits of the four 'Labour Codes' in the context of labour market reforms in India. What has been the progress so far in this regard?" — biodiv-adjacent in 2023 was:
Q. Explain the role of the Western Ghats in the climate and biodiversity of peninsular India. (10 marks, 150 words)
Answer skeleton: Climate — orographic rains, monsoon trigger, rain-shadow Deccan; Biodiversity — UNESCO WHS 2012, 1 of 8 hottest hotspots, ~7 400 plant + 1 800 vertebrate species, ~63 % amphibian endemism; Threats — Madhav Gadgil (2011) vs Kasturirangan (2013); Recommend — ESA notification, eco-corridors.
Q. Discuss the causes of depletion of mangroves and explain their importance in maintaining coastal ecology. (10 marks, 150 words)
Answer skeleton: Causes — aquaculture (shrimp), urbanisation, port expansion, cyclones, climate change, freshwater diversion, pollution. Importance — coastal shield (Odisha super-cyclone 1999 vs Sundarbans cyclones), nursery for 75 % of commercial fish, carbon sink (4× tropical rainforest per ha), biodiversity (saltwater croc, mangrove tiger, fishing cat). Conclude — MISHTI 2023 mission for 540 km² over 5 yrs.
Q. How is S4A (Scheme for Sustainable Structuring of Stressed Assets) different from other restructuring schemes? — biodiversity-relevant from 2022:
Q. Explain the purpose of the Green Grid Initiative launched at the World Leaders Summit of the COP26 UN Climate Change Conference in Glasgow.
Note: Biodiversity tie-in — GGI ("One Sun One World One Grid") reduces fossil-fuel dependence and indirect biodiversity impact; complements GBF Target 8 (climate action for biodiversity).
Q. How is "stubble burning" causing the decline of soil micronutrients in India? — adjacent ecology question; the direct biodiversity question of 2021:
Q. Discuss in detail the photochemical smog and ozone depletion. Highlight the present situation of ozone depletion over India. (15 marks)
Connection: O₃ depletion → UV → impact on phytoplankton (base of marine food web) & amphibian decline. Tie Montreal Protocol (1987) + Kigali Amendment (2016).
Q. Discuss the causes of poverty and underdevelopment in the tribal areas of India and suggest measures for tribal welfare. — biodiversity-direct 2020:
Q. Define the concept of carrying capacity of an ecosystem as relevant to an environment. Explain how understanding this concept is vital while planning for sustainable development of a region. (15 marks)
Answer skeleton: Definition (Verhulst logistic — K); types (biological vs cultural); applications — pilgrimage caps (Char Dham), tourism caps (Andaman, Spiti), grazing in BR core, urban density. Conclude — Hardin's "tragedy of the commons" + need for PA management plans.
Q. How does biodiversity vary in India? How is the Biological Diversity Act, 2002 helpful in the conservation of flora and fauna? (15 marks, 250 words)
Answer skeleton: Variation — latitudinal, altitudinal, hotspot concentration (Western Ghats, Eastern Himalaya); 10 biogeographic zones; 4 of 36 global hotspots. BD Act 2002 — 3-tier NBA-SBB-BMC; ABS regime; PBR (People's Biodiversity Register); regulation of access by foreigners; declaration of Biodiversity Heritage Sites. 2023 amendment — decriminalised offences, AYUSH facilitation. Critique — BMC operationalisation slow; ABS revenue limited.
Q. How does the cryosphere affect global climate? — adjacent. Direct biodiversity question:
Q. Coral reefs are described as the "rainforests of the sea". Discuss their importance in maintaining marine biodiversity, the threats they face, and India's conservation efforts.
Answer skeleton: Cover < 1 % of seabed but house 25 % of marine species; ecosystem services (fisheries, tourism, coastline protection, bioactive compounds). Threats — bleaching (1998, 2010, 2016, 2024 global mass-bleaching events), ocean acidification, COTS, sedimentation, blast fishing. India — Gulf of Mannar, Gulf of Kutch, Lakshadweep, Andaman, Palk Bay; protected via MNP Gulf of Kutch (1980), Gulf of Mannar BR.
Q. Mention the advantages of the cultivation of pulses because of which the year 2016 was declared as the International Year of Pulses by the United Nations. — adjacent. Biodiv-direct 2017:
Q. "Wetlands are critical ecosystems but the most threatened." In light of the statement, examine the role of the Ramsar Convention & India's Wetland (Conservation & Management) Rules 2017 in protecting wetlands.
Answer skeleton: Wetland services (carbon, flood control, fisheries, biodiversity). Threats — drainage, urbanisation, pollution, invasives. Ramsar (1971) — wise use, Montreux Record, ratified by India 1982 (89 sites, June 2025). 2017 Rules — decentralised to State Wetlands Authorities; prohibited solid waste dumping, reclamation. Limitations — defining catchment, encroachment, urban wetlands. Initiatives — Amrit Dharohar 2023, Save Wetlands Campaign 2023.
Q. Discuss the Namami Gange and National Mission for Clean Ganga programmes and causes of mixed results from the previous schemes. What quantum leap can help preserve the river Ganga better than the present situation? — biodiversity-linked.
Biodiversity angle: Gangetic dolphin (National Aquatic Animal 2009, EN, ~4 067 in 2024); gharial (CR); Mahseer; pollution impact on biodiv; Project Dolphin 2020.
Q. Bring out the causes for the formation of heat islands in the urban habitat of the world. — adjacent. Biodiversity-direct 2013:
Q. The Namibian and South African cheetah introduction in Kuno: Critically examine the ecological, legal, and management challenges. (Asked across years post-2022.)
Answer skeleton: Background — Project Cheetah 17 Sept 2022, 20 cats; SC permitted with conditions. Challenges — habitat (~750 km² vs ideal 5 000+), prey base, intra-species territoriality, summer mortality 2023 (8 deaths), local communities, second site Gandhi Sagar 2024. Way forward — Banni grasslands, Mukundra; African Lion Working Group lessons; long-term genetics.
Practice Mains — topic-aligned
Q. Explain the factors responsible for the high level of biodiversity in the Western Ghats. Why is it considered one of the world's "hottest hotspots"? (10 marks, 150 words)
Q. Critically evaluate India's Protected Area Network. Has it been adequate to halt species decline outside reserves? (15 marks, 250 words)
Q. "Project Tiger at 50 — successes, gaps, and the road ahead." Discuss with reference to NTCA's all-India tiger estimation 2022 and the 2024 inclusion of new reserves. (15 marks, 250 words)
Q. Examine the Kunming-Montreal Global Biodiversity Framework (2022). How does India's updated BSAP 2024-30 align with the "30×30" goal, and what are the financing challenges? (15 marks, 250 words)
Q. Discuss the ecological, economic, and disaster-management value of mangroves. Critically evaluate the MISHTI initiative (2023). (10 marks, 150 words)
Q. "The Biological Diversity (Amendment) Act 2023 dilutes the protection regime in the name of ease of doing business." Critically examine. (15 marks, 250 words)
Q. Explain the concept of an ecotone and discuss how India's mangrove ecosystem demonstrates ecotonal characteristics. (10 marks, 150 words)
Q. Distinguish between flagship, keystone, umbrella, and indicator species with Indian examples. Why does the Project Tiger model use the tiger as an umbrella species? (10 marks, 150 words)
Q. "Invasive alien species are the second largest driver of biodiversity loss after habitat destruction." With Indian examples (Prosopis juliflora, Lantana camara, African catfish, water hyacinth), suggest a national management framework. (15 marks, 250 words)
Q. Climate change × biodiversity: How will a +1.5 °C world reshape India's biomes by 2050? Refer to IPCC AR6 WG-II findings on South Asia. (15 marks, 250 words)
12 · Revision — 15 must-know facts
- Biosphere stretches ~11 km (deepest oceans) to ~10 km (atmosphere) above sea level — the only sphere where life occurs.
- 10 % Rule (Raymond Lindeman, 1942) — only ~10 % of energy at one trophic level is transferred to the next; rest lost as heat.
- Productivity ranking: coral reefs / estuaries / mangroves > tropical rainforest > temperate forest > savanna > tundra > open oceans (oceanic "deserts").
- Biodiversity hotspot (Norman Myers 1988; CI 1999): ≥ 1 500 endemic vascular plants AND ≥ 70 % primary vegetation lost. 36 global hotspots; India has 4 — Himalaya, Indo-Burma, W. Ghats-Sri Lanka, Sundaland.
- Rodgers & Panwar 1988 — divided India into 10 biogeographic zones: Trans-Himalaya, Himalaya, Desert, Semi-Arid, W. Ghats, Deccan Peninsula, Gangetic Plain, Coasts, NE India, Islands.
- IUCN Red List — 9 categories: EX → EW → CR → EN → VU → NT → LC → DD → NE.
- Protected Areas (2025): 106 National Parks · 573 Wildlife Sanctuaries · 123 Conservation Reserves · 220 Community Reserves · 58 Tiger Reserves · 18 Biosphere Reserves (12 on UNESCO WNBR) · 89 Ramsar Sites.
- WPA 1972 — 2022 amendment rationalised 6 schedules to 4: Sch I (highest), II (lesser), III (plants), IV (CITES).
- Project chronology: Tiger 1973 → Crocodile 1975 → Elephant 1992 → Snow Leopard 2009 → Dolphin 2020 → Cheetah 2022 → Lion 2024.
- India's tiger pop: 3 682 (NTCA 2022, ~75 % global) · Asiatic lion: 891 (2025) · Snow leopard: 718 (SPAI 2024) · Gangetic dolphin: ~4 067 (2024) · Rhino: 4 014 (2022).
- Biological Diversity Act 2002 (amended 2023) — three-tier: NBA (Chennai) → SBB → BMC; operationalises ABS.
- Conventions: Ramsar 1971 (wetlands) · CITES 1973/75 (3 Appendices) · CMS Bonn 1979 · CBD Rio 1992 (3 objectives) · Cartagena 2000 (LMOs) · Nagoya 2010 (ABS).
- Kunming-Montreal GBF (CoP-15, Dec 2022) — 4 Goals 2050 + 23 Targets 2030; Target 3 = "30×30"; finance Target 19 = $200 bn/yr; subsidy Target 18 = phase out $500 bn/yr.
- Montreux Record — Ramsar's list of threatened wetlands; India's only entries: Keoladeo (1990) & Loktak (1993). Chilika removed 2002.
- BBNJ "High Seas Treaty" adopted at UN 19 June 2023 — first legal instrument for marine biodiversity beyond national jurisdiction; India signed 25 Sept 2024.