Natural Vegetation of India

Factors Influencing Natural Vegetation

Three major physical factors determine the type and distribution of natural vegetation in India:

Rainfall Threshold → Vegetation Type

Temperature overrides rainfall above 900 m — that is why coniferous forests occur in Himalayas despite high rainfall that would produce evergreen broadleaf forests at lower altitudes.

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Champion & Seth Classification System

• H.G. Champion (1935) first published a forest-type classification for undivided India.
• S.K. Seth joined Champion (1968) — refined and finalised the standard classification still used today.
• Principle: Each forest type is treated as a distinct ecosystem (not classified purely by climate, soil or flora alone).
• Structure: 5 climate-based major groups → subdivided into 16 types based on precipitation and temperature ranges.

The 5 Major Groups

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ISFR 2023 — Forest Type Area and Carbon Stock

ISFR 2023 (18th edition) is the latest official India State of Forest Report, released by the Forest Survey of India (FSI), MoEFCC, in December 2024. ISFR 2025 has not yet been released (FSI website, April 2026).

ISFR 2023 — National Headline Figures:

GFRA 2025 (FAO, October 2025): India ranked 9th globally in total forest area (up from 10th), 3rd in annual net forest gain (2015–2025, ~1.91 lakh ha/year), and 5th among global carbon sinks (forests absorb ~150 Mt CO₂/year).

Biodiversity Distribution

• Maximum tree diversity: Tropical wet evergreen + semi-evergreen forests of the Western Ghats (TN, Kerala, Karnataka), followed by Northeastern states.
• Lowest tree diversity: Sub-tropical dry evergreen forests of J&K; forest-deficit states (Punjab, Haryana, Rajasthan).
• Karnataka — maximum species richness for trees.
• Arunachal Pradesh — maximum richness for shrubs; maximum richness overall (trees + shrubs + herbs combined); followed by TN and Karnataka.
• J&K — maximum herb species richness.

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A. Moist Tropical Forests

1. Tropical Wet Evergreen Forests (Tropical Rain Forests)

Climatic conditions:

• Annual rainfall: >250 cm
• Mean annual temperature: 25–27°C
• Dry season: distinctly short (1–2 months)

Characteristics:

• Evergreen — trees shed leaves at different times, so the forest appears green throughout the year.
• Mesophytic — adapted to moderate moisture (neither extreme wet nor dry).
• Lofty — trees reach 45–60 m; emergent layer above main canopy.
• Multi-layered canopy — sunlight barely reaches the forest floor.
• Sparse undergrowth — bamboo, ferns, climbers, epiphytes, orchids occupy lower layers.
• Rapid litter decomposition — leaf litter breaks down faster than any other biome due to heat + humidity + microbial diversity; soil surface appears almost bare.
• ISFR 2023 area: 19,572 km² (only 2.74% of forest cover — limited by strict rainfall requirement)

Distribution:

• West-facing slopes of the Western Ghats (500–1,370 m elevation) — Kerala, Karnataka, Goa, Maharashtra
• Purvanchal Hills (parts of Arunachal Pradesh, Mizoram, Nagaland)
• Andaman and Nicobar Islands

Key species: Mahogany, Mesua, White cedar, Jamun, Rosewood, Canes, Bamboo

[UPSC Prelims 2021] "Leaf litter decomposes faster than in any other biome and as a result the soil surface is often almost bare. Apart from trees, the vegetation is largely composed of plant forms that reach up into the canopy vicariously, by climbing the trees or growing as epiphytes rooted on the upper branches of trees." This describes: a) Coniferous forest b) Dry deciduous forest c) Mangrove forest d) Tropical rain forest ✓

Why d? Rapid decomposition = high heat + humidity; climbers (lianas) + epiphytes = characteristic of tropical rainforest canopy structure.

[UPSC Prelims 2015] In which of the following States do Tropical Wet Evergreen Forests occur?

1. Arunachal Pradesh 2. Himachal Pradesh 3. Mizoram Answer: c) 1 and 3 only ✓ — Himachal Pradesh is too dry and has temperate forests; wet evergreen requires >250 cm rainfall.

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2. Tropical Semi-Evergreen Forests

Transitional type between Tropical Wet Evergreen and Tropical Moist Deciduous.

Climatic conditions:

• Annual rainfall: 200–250 cm
• Mean annual temperature: 24–27°C
• Dry season: longer than in wet evergreen

Characteristics:

• Less dense than wet evergreen forests; more gregarious (form purer stands — better for commercial timber).
• Trees have buttressed trunks with abundant epiphytes.
• Species-rich forests; mix of evergreen and deciduous species.

Distribution: Western coast, Assam, lower slopes of Eastern Himalayas, Odisha, Andamans

Key species:

• Western Ghats: Laurel, Rosewood, Mesua, Thorny bamboo
• Himalayan region: White cedar, Indian chestnut, Champa, Mango

ISFR 2023 area: 69,195 km² (9.69% — 4th largest forest type)

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3. Tropical Moist Deciduous Forests

Most commercially important forest type in India.

Climatic conditions:

• Annual rainfall: 100–200 cm
• Mean annual temperature: ~27°C
• Spring and summer are distinctly dry — triggers leaf shedding

Characteristics:

• Trees shed leaves in spring and early summer (March–May); forests appear bare in April–May.
• Irregular top storey (25–60 m height); heavily buttressed trees; fairly complete undergrowth.
• More gregarious than evergreen forests → easier to exploit commercially.
• Large tracts have been cleared for cultivation.

Distribution:

• Belt along Western Ghats surrounding the evergreen belt
• Strip along Shiwalik range (terai + bhabar), 77°E to 88°E
• Hills of eastern MP and Chhattisgarh
• Chota Nagpur Plateau
• Manipur and Mizoram
• Most of Odisha; parts of West Bengal
• Andaman and Nicobar Islands

Key species: Teak (dominant), Sal, Laurel, Rosewood, Amla, Jamun, Bamboo

ISFR 2023 area: 1,31,805 km² (18.47% — 2nd largest, highest carbon stock after dry deciduous)

[UPSC Prelims 2015] In India, in which type of forest is teak a dominant tree species? a) Tropical moist deciduous ← correct b) Tropical rain forest c) Tropical thorn scrub d) Temperate forest Why? Teak thrives in warm + humid climate with distinct wet and dry seasons — exactly the tropical moist deciduous regime.

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4. Littoral and Swamp Forests (Mangroves)

• Grow in saline/brackish water (mix of sea and fresh water; salinity 0.5–35 ppt).
• Found in deltas, estuaries, creek margins — subject to tidal influence.
• Littoral forests — along sea coasts and lake shores.
• Swamp forests — confined to deltas of Ganga, Mahanadi, Godavari (Coringa WLS), Krishna, and Cauvery.

Mangroves — special adaptations:

• Pneumatophores (aerial roots for gas exchange in waterlogged soils)
• Viviparous germination — seeds germinate on the parent tree
• Salt-excluding / salt-secreting root mechanisms

Distribution:

• Dense mangroves all along coastline in sheltered estuaries, backwaters, salt marshes, mudflats.
• Sundarbans (Ganga–Brahmaputra delta, West Bengal + Bangladesh) — world's largest contiguous mangrove forest; dominant species: Sundri (Heritiera fomes).
• Other major areas: Bhitarkanika (Odisha), Pichavaram (TN), Coringa (AP), Malabar coast (Kerala)

Key species: Sundri, Agar, Rhizophora, Avicennia, Casuarina (in coastal plantations)

ISFR 2023 mangrove cover: 4,992 km² (up 17 km² from 2021; Gujarat had some loss, AP and Maharashtra gained)

[UPSC Prelims 1997] Which pair is correctly matched? a) Teak: J&K b) Deodar: MP c) Sandalwood: Kerala d) Sundari: West Bengal ✓ Sundarbans (WB) = world's largest mangrove; Sundari tree is its namesake species.

[UPSC Prelims 2015] People of Meghalaya train the roots of living trees into bridges. These living root bridges are made of: a) Meghalaya ✓ — Khasi and Jaintia communities use aerial roots of Ficus elastica (Indian rubber tree) trained over bamboo and betel nut tree trunks across streams.

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B. Dry Tropical Forests

5. Tropical Dry Evergreen Forests

Apparently paradoxical — evergreen despite low rainfall.

Climatic conditions:

• Annual rainfall: ~100 cm (mostly from Northeast monsoon, October–December)
• Mean temperature: ~28°C
• Dry season: long (March–September, before NE monsoon)

Characteristics:

• Short-statured (up to 12 m); complete canopy; bamboo and grasses not conspicuous.
• Maintains evergreen character because NE monsoon provides rain when rest of India is dry.
• Most land under these forests cleared for agriculture or Casuarina plantations.

Distribution: Exclusively along Tamil Nadu coast (Coromandel coast)

Key species: Jamun, Tamarind, Neem

ISFR 2023 area: Only 835 km² (0.12% — rarest Champion & Seth type)

Casuarina plantations:

• Resembles a feathery conifer; rapid-growing, nitrogen-fixing, salt-tolerant.
• Popular farm forestry in: Andhra Pradesh, Tamil Nadu, West Bengal, Odisha, Maharashtra, Gujarat, Karnataka.
• Used for: windbreaks on coasts, wasteland development, dune stabilisation.

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6. Tropical Dry Deciduous Forests

Most widespread forest type in India (39.30% of forest cover).

Climatic conditions:

• Annual rainfall: ~75–100 cm
• Hot summers; cold winters with no moisture

Characteristics:

• Similar to moist deciduous but grows in less rainfall areas.
• Transitional: moist deciduous on wetter side → thorn forests on drier side.
• Closed but uneven canopy; trees 20 m tall; enough light reaches ground for grass and climbers.
• Large tracts cleared for agriculture; degraded by overgrazing and fire.

Distribution: Irregular wide strip from the foot of the Himalayas to Kanyakumari — except Rajasthan, Western Ghats, and West Bengal.

Key species: Teak, Axlewood, Rosewood, Common bamboo, Red sanders, Laurel

ISFR 2023 area: 2,80,547 km² (39.30% — largest forest type by area in India)

[UPSC Prelims 2023] How many of these are deciduous trees?

1. Jackfruit (Artocarpus heterophyllus) 2. Mahua (Madhuca indica) 3. Teak (Tectona grandis) Answer: b) Only two (Mahua and Teak) — Jackfruit is evergreen.

[UPSC Prelims 2021] Which statements about Moringa and Tamarind are correct?

1. Moringa is a leguminous evergreen tree — WRONG (Moringa is deciduous, not leguminous)
2. Tamarind is endemic to South Asia — WRONG (native to tropical Africa)
3. Tamarind is collected as minor forest produce in India — CORRECT
4. India exports tamarind and Moringa seeds — CORRECT
5. Seeds of Moringa and Tamarind can be used in biofuel production — CORRECT Answer: b) 3, 4 and 5 ✓

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7. Tropical Thorn Forests

Climatic conditions:

• Annual rainfall: <75 cm
• Humidity: <50%
• Mean temperature: 25–30°C
• Long dry season

Characteristics:

• Trees are low, widely scattered; long roots tap deep groundwater.
• Acacias and Euphorbias prominent; Indian wild date common; grasses grow in rainy season.
• Thorns and spines — xerophytic adaptation to reduce water loss and herbivory.
• Degenerate into desert scrub toward Thar desert (Rajasthan).

Distribution:

• Rajasthan, SW Punjab, W Haryana, Kutch and Saurashtra — degenerates into desert toward Thar.
• Leeward side of Western Ghats — Vidarbha (Maharashtra), Hyderabad-Karnataka (Karnataka), Telangana, Andhra Pradesh, Tamil Nadu.

Key species: Neem, Babul (Acacia nilotica), Cacti, Khejri (Prosopis cineraria — State tree of Rajasthan)

ISFR 2023 area: 13,259 km² (1.86%)

[UPSC Prelims 2002] Open stunted forests with bushes and small trees having long roots and sharp thorns are found in: a) Eastern Orissa b) NE Tamil Nadu c) Shivalik and Terai d) Western Andhra Pradesh ✓ Rayalaseema region (W Andhra) has semi-arid climate → thorn scrub vegetation.

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C. Montane Sub-Tropical Forests

8. Sub-Tropical Broad-leaved Hill Forests

Climatic conditions:

• Mean annual rainfall: 75–125 cm
• Temperature: 18–21°C

Characteristics:

• Evergreen species-rich forests; a "stunted rainforest" — not as luxuriant as tropical evergreen.
• Climbers and epiphytes common; ground flora rich.

Distribution:

• Eastern Himalayas east of 88°E, altitudes 1,000–2,000 m.
• South India: Nilgiris, Annamalai, Palani hills (1,070–1,525 m) — locally called Shola forests.
• Also: Mahabaleshwar, Satpura and Maikal summits, Bastar highlands, Mt. Abu (Aravallis).

Key species: Evergreen oaks, Chestnuts, Ash, Beech, Sal, Pines

ISFR 2023 area: 31,015 km² (4.35%)

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9. Sub-Tropical Moist Pine Forests (Chir Pine Forests)

Distribution:

• Western Himalayas, 73°E to 88°E, elevations 1,000–2,000 m
• Hilly regions of Arunachal Pradesh, Manipur, Naga Hills, Khasi Hills

Characteristics:

• Chir (Pinus roxburghii) or Chil — dominant species, forms pure stands.
• Provides valuable timber (furniture, boxes, buildings) + resin and turpentine.

ISFR 2023 area: 17,801 km² (2.49%)

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10. Sub-Tropical Dry Evergreen Forests

Distribution: Bhabar, Shiwaliks, and western Himalayas up to ~1,000 m

Climatic conditions:

• Annual rainfall: 50–100 cm (15–25 cm in December–March)
• Hot summers; very cold winters

Characteristics:

• Low scrub forest with small evergreen stunted trees and shrubs.
• Dominant species: Olive, Acacia modesta, Pistacia (pistachio relatives).

ISFR 2023 area: 173 km² (0.02% — smallest Champion & Seth type)

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D. Montane Temperate Forests

11. Montane Wet Temperate Forests

Climatic conditions:

• Altitude: 1,800–3,000 m
• Mean annual rainfall: 150–300 cm
• Mean temperature: 11–14°C

Characteristics:

• Closed evergreen forests; trees with large girth.
• Trunks clothed with mosses, ferns, lichens — indicator of high humidity.
• Trees rarely exceed 6 m height.

Distribution: Higher hills of Tamil Nadu and Kerala; Eastern Himalayan region (Sikkim, Darjeeling, Arunachal Pradesh)

Key species: Deodar, Chilauni, Indian chestnut, Birch, Blue pine, Oak, Hemlock

ISFR 2023 area: 20,185 km² (2.83%)

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12. Himalayan Moist Temperate Forests

Climatic conditions:

• Annual rainfall: 150–250 cm

Characteristics:

• Mainly coniferous species in mostly pure stands.
• Trees 30–50 m high; open forests with shrubby undergrowth of oaks, rhododendrons, some bamboo.
• Provides fine wood for construction, timber, and railway sleepers.

Distribution: Entire Himalayan range (Kashmir, HP, Uttarakhand, Darjeeling, Sikkim) at 1,500–3,300 m

Key species: Pines, Deodar (Cedrus deodara), Silver firs, Spruce, Oak, Rhododendron

ISFR 2023 area: 28,727 km² (4.02%)

[UPSC Prelims 2014] Travelling through the Himalayas, which plants grow naturally?

1. Oak 2. Rhododendron 3. Sandalwood Answer: a) 1 and 2 only ✓ — Sandalwood (Santalum album) prefers warm, dry southern India; not found in Himalayas.

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13. Himalayan Dry Temperate Forests

Climatic conditions:

• Precipitation: <100 cm, mostly as snow
• Found in rain-shadow zones where SW monsoon is very feeble

Characteristics:

• Coniferous forests with xerophytic shrubs.
• Open forest; sparse tree cover.

Distribution: Inner dry ranges of Himalayas — Ladakh, Lahul, Chamba, Kinnaur, Garhwal, Sikkim (all in rain-shadow of outer Himalayas)

Key species: Deodar, Oak, Ash, Olive, Juniper, Willow

ISFR 2023 area: 4,255 km² (0.60%)

[UPSC Prelims 2008] Which one is NOT essentially a Himalayan vegetation species? a) Juniper b) Mahogany c) Silver fir d) Spruce Answer: b) Mahogany ✓ — Mahogany is native to Central and South America/Caribbean; a tropical hardwood, not Himalayan.

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E. Alpine Forests

Alpine vegetation zone: above 2,900–3,500 m up to the snowline.

14. Sub-Alpine Forests

• Altitude: 2,900–3,500 m
• Mixture of coniferous and broad-leaved trees — conifers reach ~30 m; broad-leaved only ~10 m.
• Transition from high-altitude temperate to open alpine scrub.
• Key species: Fir, Spruce, Rhododendron (Rhododendron arboreum — State flower of Uttarakhand, HP, Nagaland)

ISFR 2023 area: 12,672 km² (1.78%)

15. Moist Alpine Scrub

• Altitude: 3,000 m → snowline
• Low, evergreen, dense growth of Rhododendron and Birch.
• Rich in mosses, lichens (indicates high moisture even at extreme altitude).

ISFR 2023 area: 652 km² (0.09%)

16. Dry Alpine Scrub

• Altitude: >3,500 m — the uppermost limit of vegetation before permanent snow.
• Xerophytic dwarf shrubs — adapted to cold, wind, low moisture.
• Found in dry zones (Ladakh, Trans-Himalaya).
• Key species: Juniper, Honeysuckle (Lonicera), Artemisia, Ephedra

ISFR 2023 area: 2,396 km² (0.34%)

Alpine vegetation limit — Eastern vs Western Himalayas: Alpine vegetation extends to ~3,000 m in Western Himalayas but up to ~4,000 m in Eastern Himalayas. Reason: Eastern Himalayas are closer to the Bay of Bengal and receive more monsoon rainfall → higher moisture availability → vegetation survives at greater elevation. (Not because eastern rocks are more fertile or eastern Himalayas are higher.)

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Bamboo

Biology and Distribution

• Bamboo is a perennial grass (not a tree), among the fastest-growing plants on Earth.
• Thrives across tropical, sub-tropical, and mildly temperate zones.
• Two rhizome types:
  • Monopodial (running/non-clumping) — found in temperate regions; can be invasive.
  • Sympodial (clumping) — natural in tropical regions; non-invasive; compact growth.

India:

• Bamboo grows naturally everywhere except the Kashmir valley.
• Most abundant in: Northeastern states (Assam, Meghalaya, Mizoram, Arunachal Pradesh) + West Bengal — account for >50% of India's bamboo resources.
• Other bamboo-rich states: Andaman & Nicobar, Chhattisgarh, MP, Western Ghats.
• India's bamboo-bearing area (ISFR 2023): 1,54,670 km²

Global context (GFRA 2025):

• India has ~11.8 million ha of bamboo forests — nearly 40% of global bamboo area.
• Ranks 1st globally in bamboo area.
• India has 136 bamboo species — 2nd richest in species diversity after China.
• China still dominates exports (68% of global bamboo and rattan products).

Importance

Indian Forest Act Amendment (2017)

The Indian Forest Act 1927 was amended in 2017 to remove bamboo from the definition of "trees".

• Bamboo grown outside forests no longer requires felling permits or transit permits.
• Anyone can cultivate and trade bamboo and bamboo products freely.
• Objective: Promote bamboo cultivation on private land, farmlands, homesteads.

National Bamboo Mission (NBM)

• Restructured NBM launched in 2018 under MoEFCC.
• Objective: Holistic growth of bamboo sector through an area-based, regionally differentiated strategy.
• Focus states: Northeastern states, MP, Maharashtra, Chhattisgarh, Odisha, Karnataka, Uttarakhand, Bihar, AP.
• Strategy: Promote plantations on farmers' fields, homesteads, community lands, wastelands, along irrigation canals.
• Sets up primary processing centres near plantations to cut transportation costs.
• Forward integration: Strengthen marketing of bamboo products and handicrafts.
• Skills training via National Skill Development Agency's Sector Skill Councils.

Project BOLD

• BOLD = Bamboo Oasis on Lands in Drought
• Launched by the Khadi and Village Industries Commission (KVIC).
• Objective: Create bamboo-based green patches in arid and semi-arid land zones.
• Dual purpose: Reduce desertification + provide livelihood to rural communities.

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Mangroves — Additional Detail

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Forest Fringe Villages

• Census 2011: ~6,50,000 total villages; ~1,70,000 villages are forest fringe villages.
• These villages depend on forests for: fuelwood, fodder, small timber, bamboo, Non-Timber Forest Products (NTFPs).

State-wise dependence rankings:

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GFRA 2025 — India's Global Standing

The Global Forest Resources Assessment (GFRA) 2025, released by FAO in Bali on 22 October 2025, gave India the following rankings:

Global context: Total global forest area = ~4.14 billion ha (~32% of Earth's land area); annual net loss fell from 10.7 million ha/year (1990–2000) to 4.12 million ha/year (2015–2025).

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UPSC Corner

Key One-Liners for Prelims

• Champion & Seth classification: 5 groups, 16 types — ecosystem-based, not climate or flora alone
• Largest forest type by area: Tropical Dry Deciduous (39.30%, 2,80,547 km²) — ISFR 2023
• Rarest forest type by area: Tropical Dry Evergreen (835 km²) — Tamil Nadu coast only
• Total forest cover (ISFR 2023): 7,15,343 km² = 21.76% of India's area
• Forest + Tree cover: 8,27,357 km² = 25.17%
• Mangroves (ISFR 2023): 4,992 km² — India ranks 2nd globally
• Sundarbans = world's largest contiguous mangrove; dominant species = Sundri
• Karnataka = max tree species richness; Arunachal Pradesh = max overall species richness
• Bamboo: India = 1st globally in bamboo area (~11.8 million ha, 40% of world — GFRA 2025)
• Indian Forest Act 1927 amended 2017 — bamboo removed from "trees" definition
• India's global forest rank: 9th in area, 3rd in annual forest gain (GFRA 2025)
• Teak: Tropical Moist Deciduous forests; Deodar: Himalayan Moist Temperate
• Chir/Chil pine: Sub-tropical Moist Pine forests (W. Himalayas 1,000–2,000 m)
• Shola forests = sub-tropical broadleaved hill forests in the Nilgiris and south India hills
• Alpine vegetation limit: ~3,000 m (W. Himalayas) vs ~4,000 m (E. Himalayas) — reason: more monsoon rainfall in east

Mains GS1 Questions

1. "Identify and discuss the factors responsible for the diversity of natural vegetation in India. Assess the significance of wildlife sanctuaries in rainforest regions." [UPSC Mains 2023]
2. "What are the Champion and Seth forest types? How does the distribution of these forest types reflect India's climatic diversity?"
3. "Discuss the ecological, economic, and cultural significance of bamboo in India. What policy measures has India taken to promote the bamboo sector?"
4. "Examine the importance of mangrove ecosystems and assess the threats to India's mangrove cover."

MCQ Trap Awareness

• Trap: "Teak is found in tropical rain forests" → Wrong — teak is dominant in Tropical Moist Deciduous forests.
• Trap: "Sandalwood is found in Himalayas" → Wrong — sandalwood prefers warm, dry southern India; not Himalayan.
• Trap: "Mahogany is a Himalayan species" → Wrong — native to Central/South America; tropical hardwood.
• Trap: "Tamarind is endemic to South Asia" → Wrong — native to tropical Africa.
• Trap: "Moringa is a leguminous evergreen tree" → Wrong — Moringa is deciduous and NOT a legume.
• Trap: "India has the 2nd largest bamboo area globally" → Wrong — India is 1st globally in bamboo area (GFRA 2025); 2nd in species diversity (after China).
• Trap: "ISFR 2025 has been released" → Wrong (as of April 2026) — latest official ISFR is 2023 (18th edition); ISFR 2025 not yet released.
• Trap: "India's total forest cover is 25.17% of its area" → Partially wrong — 25.17% is forest + tree cover combined; forest cover alone is 21.76%.
• Trap: "Sundarbans mangroves are in West Bengal only" → Incomplete — Sundarbans straddle India (WB) and Bangladesh; Indian portion is in WB.
• Trap: "India ranks 10th globally in forest area" → Outdated — India moved to 9th (GFRA 2025, October 2025).
• Trap: "Bamboo was removed from the Forest Act in 2018" → Wrong — amendment passed in 2017.