Physical Geography · Topic 14 · GS Paper 1 & 3

Biogeography & Ecosystems — Biomes, Marine Life Zones, Biodiversity Hotspots & India's 10 Biogeographic Zones

Biogeography is the geography of life — why tigers in India and jaguars in Amazon, why tropical rainforests cling to the equator and tundra to the poles, why Western Ghats and Eastern Himalaya carry a quarter of India's species in 6 % of land. This capstone topic of the Physical Geography series builds the full picture: biosphere & biomes (10 terrestrial + marine), ecosystem structure & function (energy flow · 10 % rule · pyramids · biogeochemical cycles), ecological succession, marine ecosystems (estuary · mangrove · coral reef · pelagic depth zones · hydrothermal vents), 36 global biodiversity hotspots (India's 4 — Himalaya, Indo-Burma, W. Ghats-Sri Lanka, Sundaland), Rodgers & Panwar's 10 biogeographic zones of India, IUCN Red List, the in-situ + ex-situ conservation architecture (NP · WLS · BR · CR · TR · Ramsar · CBD · CITES · GBF 30×30), and India's flagship species projects (Tiger 1973 · Elephant 1992 · Cheetah 2022 · Dolphin 2020 · Lion 2024). All diagrams are labelled, Prelims and Mains banks strictly separated.

Physical Geography · Topic 14 · ~45 min read · Updated June 2026

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.

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.

Fig 14.1 — World biomes: Panel A shows the idealised latitudinal arrangement from the equator polewards, with each band labelled inside its colour swatch — rainforest at 0°, savanna and desert at sub-tropics, temperate grassland and deciduous in mid-latitudes, taiga at high-mid, tundra near the Arctic/Antarctic Circle, ice caps at the poles. Panel B is the altitude analogue on a tropical mountain (Himalaya) — from tropical deciduous at base, through temperate broadleaf, taiga-like conifers, sub-alpine, alpine meadow, to nival snow at ≥ 5 000 m — mirroring the latitudinal sequence in just 6 km of climb (≈ 6.5 °C drop per 1 000 m).

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).

Fig 14.2 — Energy flow & food web: Panel A shows the 10 % rule (Lindeman 1942) as a 5-tier pyramid — 10 000 kcal of producer energy yields just 1 kcal at the top; orange arrows show ~90 % heat loss at each transfer (respiration + unconsumed parts). Side leaders give the equivalent organisms (grass → grasshopper/deer → frog/wolf → snake/big cat → hawk/apex). Panel B is a simplified grassland food web: arrows point "is eaten by" — producers (green) feed herbivores (light green), feeding secondary carnivores (gold), all converging at the apex hawk (dark red). The legend lists trophic colours.

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.

Fig 14.3 — Global carbon cycle: boxes are pools (Pg C, dark numbers); arrows are fluxes (Pg C/yr). Green = downward sinks (photosynthesis 123 · ocean dissolution 80), orange = upward natural fluxes (respiration 119 · outgassing 78), dark-red = anthropogenic (fossil fuel 9.4 + land-use change 1.0). Net result: +5 Pg C/yr accumulating in the atmosphere — visible as the rise from 280 ppm pre-industrial to 422 ppm today (NOAA Mauna Loa, 2024). Largest mobile pool is the deep ocean (~37 000 Pg C); largest land pool is soil + permafrost (~2 300 Pg C).

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)

Fig 14.4 — Pelagic depth zones: the ocean water column is split into five vertical layers — Epipelagic (0-200 m, sunlit, ~90 % of marine life), Mesopelagic (200-1 000 m, twilight, bioluminescent fauna), Bathypelagic (1 000-4 000 m, midnight zone), Abyssopelagic (4 000-6 000 m, polymetallic nodules + vents) and Hadalpelagic (6 000-11 000 m, trenches like Mariana). Right column gives indicator fauna with leader lines into the zone. Far-right photic/dysphotic/aphotic bar tracks the light regime; left scale marks depth + pressure (~1 bar at surface to ~1 100 bar at Mariana). Yellow vertical lines depict penetrating sunlight stopping at ~200 m.

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

Fig 14.5 — Global biodiversity hotspots: Conservation International recognises 36 hotspots covering only ~2.4 % of land but holding ~50 % of endemic plants. India hosts four (gold stars): 1 Himalaya (N + NE India + Nepal, Bhutan), 2 Indo-Burma (NE India, Myanmar, Indo-China), 3 Western Ghats & Sri Lanka (W. coast + SL), 4 Sundaland (Nicobar Is + Indonesia + Malaysia). Red dots mark the remaining 32 hotspots. Criteria (Myers 1988, CI 1999): ≥ 1 500 endemic vascular plants AND ≥ 70 % primary vegetation lost.

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 · MoEFCC

WII 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

Trans-Himalayans Desert Semi-arid Western-Ghats Deccan Gangetic Coast NE Islands" Cross-walk: Hotspots (CI) ⊂ Zones; e.g., W. Ghats hotspot ≈ Zone 5; Indo-Burma hotspot ≈ Zone 9; Himalaya hotspot ≈ Zone 1+2; Sundaland ≈ Nicobar part of Zone 10.

Fig 14.6 — India's 10 biogeographic zones (Rodgers & Panwar 1988, rev. 2002): each zone is colour-coded on the schematic map and listed in the right-hand legend with % of India's area + signature fauna. Deccan Peninsula (42 %) is by far the largest; Islands (0.3 %) the smallest. The framework underpins India's Protected Area Network & National Wildlife Action Plan. Cross-walk to CI hotspots noted at the bottom of the legend.

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

Memory hook (12 WNBR): "Nilgiri Nanda Nokrek Great-Nicobar Gulf-Mannar Sundarbans Simlipal Pachmarhi Khangchendzonga Agasthyamalai Achanakmar Panna" — the 6 NOT on WNBR are Manas, Dibru-Saikhowa, Dehang-Debang, Kachchh, Cold Desert, Seshachalam.

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.

UPSC trick — confusion zone: after the WPA 2022 amendment, "Schedule I" is not just mammals — it now combines old Sch I + Sch II Part II. Vermin schedule (old V) was dropped. Plants are now Schedule III (not VI). CITES species are now Schedule IV.

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).

UPSC trick — easy to confuse:

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.

Mnemonic — convention years: "71 Ramsar · 73 CITES · 79 Bonn · 92 Rio (CBD/UNFCCC/UNCCD) · 2010 Nagoya · 2022 GBF · 2023 BBNJ"

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.

UPSC CSE 2024 · Prelims

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).

UPSC CSE 2023 · Prelims

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.)

UPSC CSE 2023 · Prelims

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.

UPSC CSE 2022 · Prelims

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.

UPSC CSE 2021 · Prelims

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).

UPSC CSE 2020 · Prelims

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).

UPSC CSE 2020 · Prelims

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.

UPSC CSE 2019 · Prelims

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.

UPSC CSE 2019 · Prelims

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.

UPSC CSE 2018 · Prelims

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.

UPSC CSE 2018 · Prelims

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.

UPSC CSE 2017 · Prelims

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.

UPSC CSE 2017 · Prelims

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.

UPSC CSE 2016 · Prelims

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.

UPSC CSE 2016 · Prelims

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.

UPSC CSE 2015 · Prelims

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.

UPSC CSE 2014 · Prelims

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.

UPSC CSE 2013 · Prelims

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.

UPSC CSE 2012 · Prelims

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.

UPSC CSE 2011 · Prelims

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)

Practice Prelims · MCQ

Q. Who coined the term "ecosystem"? (a) Haeckel 1866 (b) Tansley 1935 (c) Lindeman 1942 (d) Odum 1953

Answer: (b) Arthur Tansley, 1935.

Practice Prelims · MCQ

Q. The "10 % Law" of energy transfer was proposed by? (a) Tansley (b) Lindeman (c) Odum (d) Elton

Answer: (b) Raymond Lindeman, 1942.

Practice Prelims · MCQ

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).

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

Q. Rodgers & Panwar (1988) divided India into how many biogeographic zones? (a) 8 (b) 9 (c) 10 (d) 12

Answer: (c) 10.

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

Q. Number of Tiger Reserves in India (2025)? (a) 50 (b) 54 (c) 58 (d) 62

Answer: (c) 58 (Madhav, MP — 58th, 2025).

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

Q. Asiatic lion population (Census 2025)? (a) 674 (b) 758 (c) 891 (d) 1 020

Answer: (c) 891 — Gir & Greater Gir.

Practice Prelims · MCQ

Q. India's first Biosphere Reserve (1986)? (a) Nanda Devi (b) Nilgiri (c) Sundarbans (d) Nokrek

Answer: (b) Nilgiri.

Practice Prelims · MCQ

Q. India has 18 Biosphere Reserves; how many are on UNESCO's WNBR? (a) 9 (b) 10 (c) 12 (d) 15

Answer: (c) 12.

Practice Prelims · MCQ

Q. India's Ramsar Site count (June 2025)? (a) 75 (b) 80 (c) 85 (d) 89

Answer: (d) 89 — largest network in Asia.

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

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).

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

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).

Practice Prelims · MCQ

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).

Practice Prelims · MCQ

Q. WPA 1972 — after 2022 amendment, how many schedules? (a) 4 (b) 5 (c) 6 (d) 7

Answer: (a) 4 — rationalised from earlier 6.

Practice Prelims · MCQ

Q. The National Biodiversity Authority is headquartered at? (a) New Delhi (b) Dehradun (c) Chennai (d) Hyderabad

Answer: (c) Chennai (est. 2003).

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

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.

Practice Prelims · MCQ

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").

Practice Prelims · MCQ

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).

UPSC CSE 2023 · GS-3

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.

UPSC CSE 2022 · GS-3

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.

UPSC CSE 2022 · GS-3

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).

UPSC CSE 2021 · GS-3

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).

UPSC CSE 2020 · GS-3

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.

UPSC CSE 2019 · GS-3

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.

UPSC CSE 2018 · GS-3

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.

UPSC CSE 2017 · GS-3

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.

UPSC CSE 2016 · GS-3

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.

UPSC CSE 2013 · GS-3

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

Practice Mains · GS-1/3

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)

Practice Mains · GS-3

Q. Critically evaluate India's Protected Area Network. Has it been adequate to halt species decline outside reserves? (15 marks, 250 words)

Practice Mains · GS-3

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)

Practice Mains · GS-3

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)

Practice Mains · GS-3

Q. Discuss the ecological, economic, and disaster-management value of mangroves. Critically evaluate the MISHTI initiative (2023). (10 marks, 150 words)

Practice Mains · GS-3

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)

Practice Mains · GS-1

Q. Explain the concept of an ecotone and discuss how India's mangrove ecosystem demonstrates ecotonal characteristics. (10 marks, 150 words)

Practice Mains · GS-3

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)

Practice Mains · GS-3

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)

Practice Mains · GS-3

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.

Mini-reference

Biosphere depth (oceans)~11 km
Biosphere height (air)~10 km
Earth species described~2.16 M
Earth species estimated~8.7 M
India species~1.04 lakh fauna + 55 K flora
India % world land2.4 %
India % world species~7-8 %
10 % rule (Lindeman)1942
Global hotspots (CI)36
India hotspots4
Rodgers-Panwar zones10 (1988)
National Parks106
Wildlife Sanctuaries573
Conservation Reserves115
Community Reserves220
Tiger Reserves57 (Dholpur 2024)
Elephant Reserves33
Biosphere Reserves (India)18
BR in UNESCO MAB12
Ramsar sites (India)85
Project Tiger1 April 1973
Project Elephant1992
Project Cheetah17 Sept 2022
Project Dolphin2020 (15 Aug)
Project Lion2024
Tiger census 20223 682
Asiatic lion census 2025891
Elephant census 201729 964
Wildlife Protection Act1972 (am. 2022)
Biological Diversity Act2002 (am. 2023)
CBD adopted1992 Rio
Cartagena Protocol2000
Nagoya Protocol2010
GBF 30×30COP-15, 2022
BBNJ Treaty2023
CITES adopted1973 Washington
Ramsar Convention1971 Iran
IUCN Red List categories9

Keyword cloud

BiosphereBiomeRainforestSavannaDesertMediterraneanSteppeTaigaTundraMountain biomeMangroveCoralEstuaryKelp forestHydrothermal ventEpipelagicMesopelagicBathypelagicAbyssopelagicHadalpelagicPhotic zoneAphotic zoneGPPNPP10 % ruleTrophic levelFood chainFood webEcological pyramidLindeman 1942Carbon cycleNitrogen cyclePhosphorus cycleHydrological cycleEutrophicationSuccessionClimax communityHydrosereXerosereEcotoneEdge effectKeystone speciesFlagship speciesUmbrella speciesIndicator species36 hotspotsConservation InternationalHimalaya hotspotIndo-BurmaWestern Ghats-Sri LankaSundalandRodgers Panwar10 biogeographic zonesIUCN Red ListEX EW CR EN VU NT LC DD NEProject TigerProject ElephantProject CheetahProject DolphinProject LionSnow LeopardNTCAWII DehradunSACONZSIBSIWPA 1972BD Act 2002NBASBBBMCRamsar 1971Montreux RecordCBD 1992Cartagena 2000Nagoya 2010GBF Kunming-Montreal 202230×30 targetCITES 1973BBNJ 2023MAB UNESCO

Quick self-check

Who proposed the 10 % rule? Year?
4 biodiversity hotspots in India?
9 IUCN Red List categories — sequence?
Year Project Tiger launched? First 9 reserves?
Difference between Biosphere Reserve and National Park?
5 pelagic depth zones in correct order.
3 CITES Appendices — what does each protect?
Difference between flagship, keystone, umbrella species?
What is the "Montreux Record" in the Ramsar Convention?
Targets of GBF 30×30 (COP-15, 2022).

Biogeography & Ecosystems — Biomes, Marine Life Zones, Biodiversity Hotspots & India's 10 Biogeographic Zones

Why this topic matters for UPSC

Contents

1 · Biosphere & biomes of the world

Two index biomes — closer look

2 · Ecosystem — structure, function, energy flow

Structure — two components

Function — five processes

Energy flow & the 10 % rule

3 · Biogeochemical cycles

3.1 Carbon cycle

3.2 Nitrogen cycle (gist)

3.3 Phosphorus, sulphur, hydrological cycles (one-liners)

4 · Ecological succession

5 · Marine ecosystems & pelagic depth zones

5.1 Pelagic depth zones (the water column)

5.2 Coastal & special marine ecosystems

Coral reefs — quick UPSC facts

6 · Biodiversity & 36 global hotspots

Biodiversity hotspot — definition (Norman Myers 1988; CI 1999)

7 · India — 10 biogeographic zones (Rodgers & Panwar 1988)

8 · IUCN Red List & key Indian species

9 Red List categories (memorise order)

Special species categories (frequent UPSC trick)

India-specific landmark species & latest counts

9 · Conservation architecture in India

9.1 In-situ vs Ex-situ — the two pillars

9.2 Protected Area Network (PAN) — five categories

9.3 Biosphere Reserves (BR) — UNESCO MAB programme

9.4 Other in-situ designations

9.5 Flagship species-recovery projects — chronological

9.6 Key institutions

9.7 Legal framework — five pillars

10 · Global biodiversity conventions & frameworks

11 · Previous-Year Questions (PYQs) — Prelims & Mains, strictly separate

A · Prelims — Direct UPSC questions

Practice Prelims — topic-aligned (one-liners)

B · Mains — Direct UPSC questions

Practice Mains — topic-aligned

12 · Revision — 15 must-know facts