Soils and Natural Vegetation of India

Flagship: what this is and why CAPF cares

Soil is the weathered, living top layer that feeds agriculture, and natural vegetation is the plant cover that would grow without human interference. CAPF tests both as matching tables: soil to region, soil to crop, vegetation to rainfall band, and the famous wildlife parks to their States and signature species. The security value is the terrain again. The Sundarbans mangroves form a porous riverine border with Bangladesh that the Border Security Force patrols by boat; the thick forests of central India (the red and laterite soil belt) overlap with the left-wing-extremism theatre where the Central Reserve Police Force operates; the alpine zones along the LAC and LoC are the Indo-Tibetan Border Police's and the Army's ground; and wildlife and timber smuggling across the open Nepal and Bhutan borders fall to the Sashastra Seema Bal. The anchor texts are NCERT Class XI, India: Physical Environment (soils and natural vegetation) and the Indian Council of Agricultural Research soil classification.

Soil formation and properties (orientation)

Soils form by the weathering of parent rock under the influence of climate, relief, vegetation, parent material and time. This is why the black soil sits exactly on the Deccan Trap (formed in situ from basalt) while the alluvial soil is transported and deposited far from its source rock. Soil profile terms the exam may touch are the horizons (the topsoil A horizon rich in humus, the subsoil B horizon of accumulation, and the weathered parent C horizon) and texture (the sand-silt-clay proportion that decides drainage and fertility). Black soil is clay-rich and moisture-retentive; alluvial soil is loamy and well-drained; laterite is coarse and leached.

Soils reference table

Soil to dominant State, for quick matching:

The altitudinal zonation of Himalayan forest

The clearest example of vegetation following climate is the change up a Himalayan slope: tropical deciduous and sal at the foot, then wet and moist temperate forest of oak and chestnut, then the temperate conifers (chir pine lower, then deodar, blue pine, silver fir and spruce higher), then the birch and rhododendron krummholz near the tree line, and finally the alpine meadows (the bugyals or margs, such as Gulmarg and Sonamarg) before the permanent snow. This zonation is why the same latitude carries tropical forest in the valley and tundra on the ridge.

Vegetation reference table

Forest, wetlands and biosphere reserves

The Forest Survey of India reports the country's forest and tree cover at roughly a quarter of the geographical area, against the National Forest Policy goal of one third. Madhya Pradesh has the largest forest area by extent, while the north-eastern States and Lakshadweep have the highest percentage cover. India has a network of UNESCO-recognised biosphere reserves (the Nilgiri Biosphere Reserve was the first, declared in 1986) and a long list of Ramsar wetlands of international importance (Chilika, Keoladeo, Loktak, Wular, the Sundarbans, Sambhar and many more).

Conservation tiers worth distinguishing: a national park is the strictest, with no private rights; a wildlife sanctuary allows some regulated activity; a biosphere reserve is a large zoned ecosystem (core, buffer, transition); a tiger reserve is managed under Project Tiger; and a Ramsar site is a wetland of international importance. India is also home to four of the world's biodiversity hotspots, in whole or part: the Himalaya, the Indo-Burma region, the Western Ghats and Sri Lanka, and the Sundaland (Nicobar Islands).

Major Ramsar wetlands the exam draws on, by State:

Vegetation by region (orientation)

Wildlife and protected areas (high-yield matching)

National symbols and conservation programmes (high-yield):

Tiger reserves of note include Jim Corbett, Ranthambore, Bandhavgarh, Kanha, Sundarbans, Periyar, Nagarjunsagar-Srisailam (the largest) and Sariska; the tiger population is tracked by the National Tiger Conservation Authority.

Security and strategic angle

Forested and protected frontiers are operational terrain for the central forces. The Sundarbans mangroves form a porous riverine border with Bangladesh that the Border Security Force patrols by boat and from floating border outposts; the dense tidal cover, the shifting channels and the man-eating tiger make it among the hardest borders to police in the world. The thick dry-deciduous forests of central India (the red and laterite soil belt of Chhattisgarh, Jharkhand and Odisha) overlap with the left-wing-extremism corridor, where the Central Reserve Police Force and its CoBRA jungle-warfare units operate, the canopy and the terrain favouring the ambusher. The high alpine and montane zones along the LAC and LoC are the Indo-Tibetan Border Police's and the Army's ground, where the tree line and the snow line set the limits of habitation and patrol. Wildlife crime, ivory and timber smuggling across the open Indo-Nepal and Indo-Bhutan border fall in the Sashastra Seema Bal's remit. See india borders neighbours and strategic geography and indian drainage system and rivers.

Soil, vegetation and crop together (integration)

Because all three follow the same climate-and-relief controls, the exam can chain them.

This chaining underpins indian agriculture and cropping: the black soil grows cotton because of the Deccan Trap, the laterite uplands grow plantation crops, and the alluvial plains grow the food grains.

How CAPF asks it

• Matching feature to location: soil to region or crop (black to cotton, alluvial to the plains, laterite to brick); park to State; species to park.
• One-liner: most widespread soil (alluvial), the cotton soil (black/regur), oldest national park (Corbett), only home of the Asiatic lion (Gir).
• Statement-based: judge claims such as "Laterite soil forms under heavy rainfall and intense leaching" (correct) and "Black soil is the most widespread soil of India" (incorrect, alluvial is).
• Cause-effect: vegetation type linked to a rainfall band.

Authored practice:

1. The self-ploughing, moisture-retentive soil formed by the weathering of the Deccan Trap is (a) alluvial (b) red (c) black regur (d) laterite. Answer (c). It cracks when dry, "ploughing" itself, and is the cotton soil.
2. The Asiatic lion in the wild is found only in (a) Ranthambore (b) Gir (c) Kanha (d) Bandipur. Answer (b). Gir in Gujarat is its sole natural home.
3. Which vegetation type is the most widespread in India? (a) tropical evergreen (b) tropical deciduous (monsoon) (c) thorn and scrub (d) montane. Answer (b). Tropical deciduous (teak and sal) covers the largest area.
4. Consider: (1) The Sundarbans is the largest mangrove forest in the world. (2) The Sundari tree gives the Sundarbans its name. Which is or are correct? Answer: both.
5. Project Tiger was launched in (a) 1936 (b) 1972 (c) 1973 (d) 1992. Answer (c). The Wildlife Protection Act was 1972, Project Elephant 1992, and Corbett (the first park) dates to 1936.
6. Which State has the largest area under forest in India? (a) Arunachal Pradesh (b) Madhya Pradesh (c) Chhattisgarh (d) Odisha. Answer (b). Madhya Pradesh has the largest forest area by extent; the north-east leads by percentage cover.
7. The one-horned rhinoceros is the signature animal of (a) Gir (b) Kaziranga (c) Ranthambore (d) Periyar. Answer (b). Kaziranga in Assam is its stronghold.
8. Laterite soil is associated with which condition? (a) low rainfall and high salinity (b) high temperature and heavy rainfall with leaching (c) waterlogging and organic accumulation (d) the weathering of basalt. Answer (b). Leaching of silica leaves the iron-and-aluminium-rich laterite, which hardens to brick.
9. The first biosphere reserve in India, set up in 1986, is the (a) Nanda Devi (b) Sundarbans (c) Nilgiri (d) Gulf of Mannar. Answer (c). The Nilgiri Biosphere Reserve was the first.

Common confusion

• Alluvial (most widespread and fertile) versus black regur (cotton soil, Deccan Trap); regur is not the most widespread.
• Bhangar (old, kankar, higher) versus khadar (new, fertile, flood-renewed).
• Laterite (heavy rain, leaching, hardens to brick, uplands) versus red soil (moderate rain, crystalline peninsula).
• Tropical evergreen (above 200 cm) versus tropical deciduous (70 to 200 cm) versus thorn (below 70 cm).
• Corbett (oldest national park, tiger) versus Kaziranga (one-horned rhino) versus Gir (Asiatic lion).
• Project Tiger (1973) versus the Wildlife Protection Act (1972) versus Project Elephant (1992).
• Keibul Lamjao (floating park, sangai, Manipur) versus Hemis (snow leopard, largest park, Ladakh).
• Nilgiri (first biosphere reserve) versus Nanda Devi, Sundarbans and Gulf of Mannar (other reserves).
• National park (strictly protected) versus wildlife sanctuary (regulated use) versus biosphere reserve (zoned ecosystem).
• Madhya Pradesh has the largest forest area; the north-eastern States lead by percentage cover.
• Reh and usar (saline-alkaline) soils need gypsum; peaty soils are organic and waterlogged.
• Moist deciduous (teak, 100 to 200 cm) versus dry deciduous (sal, 70 to 100 cm); both are monsoon forest.
• Evergreen (over 200 cm, no leaf-fall) versus deciduous (leaf-fall in the dry season); evergreen is denser and multi-layered.

Memory hook

• Soil-to-crop: "Black cotton, red millet, alluvial wheat, laterite tea."
• Vegetation by rain: "Ever (200+), Decid (70 to 200), Thorn (under 70)."
• Khadar is the Kid (new and fertile); Bhangar is the Big old one.
• Laterite is from the Latin for brick, and it really does harden into building brick.
• Rhino-Lion-Tiger trio: Kaziranga rhino, Gir lion, Corbett the first tiger park.
• Conservation dates: "72 Act, 73 Tiger, 80 Forest, 92 Elephant."
• Hotspots: "Himalaya, Indo-Burma, Western Ghats, Sundaland" are the four that touch India.
• Sundari tree names the Sundarbans, the largest mangrove and the largest delta.
• Forest-up-the-slope ladder: "Foot deciduous, mid oak, high conifer, top meadow, then snow."

Species and park signatures (matching)

Night before

• ICAR recognises eight soil groups; alluvial is the most widespread (about 40 percent) and most fertile.
• Black regur on the Deccan Trap is moisture-retentive, self-ploughing, the cotton soil.
• Laterite forms under heavy rain and leaching, hardens to brick, supports tea and coffee on uplands.
• Vegetation follows rainfall: evergreen above 200 cm, deciduous 70 to 200 cm, thorn below 70 cm; deciduous is the most widespread.
• Sundarbans is the largest mangrove (Sundari tree); the largest delta and a BSF riverine border.
• Corbett oldest park (1936), Kaziranga rhino, Gir lion; Project Tiger 1973, Wildlife Act 1972.
• Soil to State: alluvial (UP, Bihar, Bengal), black (Maharashtra, MP, Gujarat), red (Tamil Nadu, Karnataka), laterite (Kerala uplands).
• Four biodiversity hotspots: Himalaya, Indo-Burma, Western Ghats, Sundaland (Nicobar); Nilgiri the first biosphere reserve.
• National symbols: tiger, peacock, Gangetic dolphin, elephant (heritage), banyan, lotus, mango.
• Himalayan forest zones up-slope: deciduous, temperate oak, conifers, birch, alpine meadow, snow.

Glossary

• Regur: the black cotton soil of the Deccan Trap, moisture-retentive and self-ploughing.
• Bhangar / khadar: older terrace alluvium and newer flood-renewed alluvium of the plains.
• Leaching: the washing-out of soluble minerals by heavy rain, which produces laterite.
• Reh / usar: saline and alkaline soils of dry and waterlogged tracts that need reclamation.
• Deciduous forest: forest that sheds its leaves in the dry season (teak, sal).
• Evergreen forest: dense forest that stays green all year, in the wettest belts.
• Mangrove: salt-tolerant tidal forest of the deltas (the Sundarbans).
• Bugyal: a high-altitude alpine meadow above the tree line in the Himalayas.
• Biosphere reserve: a large protected ecosystem with core, buffer and transition zones (Nilgiri was the first).
• Ramsar site: a wetland of international importance under the Ramsar Convention (Chilika, Keoladeo).
• Endemic species: a species found nowhere else, like the Asiatic lion of Gir or the hangul of Dachigam.
• Tree line / snow line: the upper limits of tree growth and of permanent snow, setting the bounds of patrol in the high Himalayas.
• Soil horizon: a layer of the soil profile (A topsoil, B subsoil, C weathered parent rock).
• Soil texture: the proportion of sand, silt and clay that decides drainage and fertility.
• Soil profile: the vertical section of soil from the surface down to the parent rock.
• Desertification: the spread of desert-like conditions, a concern on the Thar margin.
• Salinity / alkalinity: the build-up of salts (reh, usar) from over-irrigation, reclaimed with gypsum.
• Wildlife sanctuary versus national park: a sanctuary permits some regulated use, a park is strictly protected.
• Tiger reserve: a habitat managed under Project Tiger, with a core and a buffer.
• Minor forest produce: non-timber forest goods (tendu leaves, lac, honey, gums) that support tribal livelihoods.
• Forest Rights Act (2006): the law recognising the rights of forest-dwelling communities over forest land and produce.
• Krummholz: the stunted, twisted forest near the tree line in the high mountains.
• Bugyal / marg: a Himalayan alpine meadow above the conifer zone (Gulmarg, Sonamarg).
• Self-ploughing soil: black regur, which cracks deeply when dry and "turns itself".
• Mega-diverse country: one of the small group of nations holding most of the world's biodiversity, including India.
• Compensatory afforestation: planting to offset forest land diverted for other use, funded through CAMPA.
• Shelter belt: a line of trees planted to break the wind and check soil erosion, used on the Thar margin.
• Contour bunding / terracing: soil-conservation works that slow run-off on slopes and ravined land.
• Phumdi: a floating mat of vegetation, the habitat of the sangai at Keibul Lamjao on Loktak.
• Endorheic / inland drainage soil: the saline arid soils of basins without an outlet to the sea, like the Sambhar tract.
• National Tiger Conservation Authority: the body that runs Project Tiger and counts the tiger population.
• Social / agro forestry: tree-planting on farms, community land and roadsides to add to natural forest cover.
• Joint Forest Management: a model of managing forest jointly with local communities.
• Green India Mission: a national afforestation programme to expand and improve forest cover.
• Endemic and keystone species: a species unique to one area, and one whose loss would unravel its ecosystem.
• Littoral and swamp forest: the coastal and waterlogged forest type that includes the mangroves.
• Humus: the dark organic matter in soil that holds fertility, low in red and laterite soils.
• Afforestation: planting trees on land that was not recently forest, the aim of the Green India Mission.
• Sundari: the salt-tolerant mangrove tree that gives the Sundarbans its name.

Related notes

• indian agriculture and cropping
• india physiography
• indian monsoon and climate
• indian drainage system and rivers
• india borders neighbours and strategic geography
• syllabus index