Amazon rainforest

Topic: World Physical Features and Natural Regions · NCERT: Beyond NCERT

Meaning

The Amazon rainforest is the largest tropical rainforest in the world. It covers about 5.5 million sq km of the Amazon basin in South America. Most of it is in Brazil, and it is shared by nine countries and territories.

It matters because the forest makes much of its own rain. Clearing for cattle ranching, soy farming and fires could push parts of it past a tipping point, after which they turn into degraded savanna. It is also at the centre of climate diplomacy: the ACTO and COP30 at Belém (2025).

Explanation

Climate that makes the forest (Af type)

• Koeppen type Af: A = tropical humid; f = no dry season. It lies roughly between 0° and 10° N/S.
• Hot and wet all year. Every month gets rain.
• How the daily rain forms:
• The sun is high all year, so the ground heats up strongly.
• The hot air rises, cools, and its water vapour turns into clouds.

• Convectional rain (rain from rising, heated air) falls almost every afternoon.

• Annual range of temperature (the gap between the hottest and coldest month) is very small, only about 2–3°C.

Structure of the forest

• Evergreen: the trees do not all drop their leaves at the same time, so the forest stays green all year.
• Layers (storeys), from top to bottom:
• Emergents: the tallest trees, which stick out above the rest.
• Canopy: a closed roof of tree crowns that blocks most sunlight.
• Understorey: young trees and shrubs.

• Forest floor: dark, with little growth.

• Hardwoods such as mahogany, ebony and rosewood are common.

• Many species grow mixed together, so there are few pure stands (patches of one kind of tree). This makes commercial logging hard.
• Lianas (woody climbers) and epiphytes (plants that grow on other plants) are common.

Rich forest, poor soil

• Leaching:
• Heavy rain soaks down through the soil.
• It washes the nutrients out.

• A red, poor soil (laterite) is left behind.

• Most nutrients are stored in the living plants, not in the soil.

• Result: once the forest is cut, the land loses its fertility within a few years. This is why farmers practise shifting cultivation: they clear a patch, often by slash-and-burn, farm it until the soil is tired, then move on. In Brazil it is called roca.

Threats and the tipping point

• Tipping point: a point of no return. After it, a system changes to a new state and cannot easily go back.
• Moisture recycling: the trees release water vapour, and it falls again as rain further west. So the forest helps make its own rain.
• How the tipping point could be crossed:
• Forest is cleared for cattle ranching and soy, and fires are set to clear land.
• Fewer trees release less water vapour, which means less rain further west.
• Dry seasons get longer, and fires become more common.
• Past a certain threshold, parts of the forest may turn into degraded savanna.

Where it occurs

• World: the Amazon basin in South America. Most of the forest is in Brazil.
• The nine countries and territories: Brazil, Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana (an overseas territory of France).
• People: the Yanomami live in the Amazon, on the Brazil–Venezuela border.
• Belém, in Brazil's Pará state, hosted COP30 (the 30th UN Climate Change Conference) in November 2025. It was the first COP held in the Amazon [3]. The conference closed with an agreement on 22 November 2025 [4].
• Other Af rainforests: the Congo basin (Africa) and South-East Asia (Indonesia, Malaysia, Borneo, Sumatra, New Guinea).
• India: India has no Af rainforest of this size. Where rain is very heavy, as in the Western Ghats (Am), there is tropical evergreen forest. North-East India has its own form of shifting cultivation, called jhum, which is like the roca of Brazil.

Don't confuse with

• Congo Basin rainforest: this is the second-largest tropical rainforest. The order is Amazon > Congo. It is drained by the Congo river, which crosses the equator twice.
• Cuvette Centrale: the largest tropical peatland complex in the world is in the Congo Basin (DR Congo and Republic of Congo), not in the Amazon. It covers about 167,600 sq km [1].
• Cerrado and Campos: these are savannas (grassland with scattered trees) on the Brazilian Highlands, not rainforest. The Cerrado is a woody savanna and is now a soy frontier.
• Llanos: a savanna in Venezuela and Colombia, in the Orinoco basin, not the Amazon basin. It has seasonal flooding and cattle ranching.

Prelims Hooks

• The Amazon is the largest tropical rainforest, about 5.5 million sq km, and most of it is in Brazil.
• The Amazon Cooperation Treaty was signed on 3 July 1978. Its eight members formed the ACTO in 1995 to carry it out [2].
• ACTO has 8 members: Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname and Venezuela [2]. Trap: French Guiana is in the Amazon but is not a member, because it is part of France.
• COP30 → Belém, Pará, Brazil (November 2025). It was the first COP held in the Amazon [3].
• Shifting cultivation names: roca → Brazil; milpa → Mexico and Central America; ladang → Malaysia and Indonesia; jhum → North-East India.
• People and region: Yanomami → Amazon (Brazil–Venezuela border); Mbuti → Congo basin.

Mains Points

• Amazon tipping point (GS-III):
• Cattle and soy clearing plus fire cut the forest's moisture recycling. This brings longer dry seasons and more fires.
• Past a threshold, parts of the forest may turn into degraded savanna. A forest that now helps make rain and supports wildlife and people like the Yanomami could become a weaker landscape.

• Response: regional cooperation through the ACTO (1978 treaty) [2], and climate diplomacy centred on the Amazon at COP30, Belém (2025) [3][4].

• Poor soils under rich forest (GS-I):

• Leaching leaves laterite soils with few nutrients, because most nutrients are locked in the living plants.

• Cleared land loses fertility within a few years. This explains shifting cultivation (roca in Brazil, jhum in North-East India) and why ranching and farming keep pushing into new forest.

• Comparison of rainforest threats (GS-I/III):

• Amazon: cattle, soy and fire.
• Borneo and Sumatra: oil palm plantations, plus peat fires that cause haze across the region.
• Congo Basin: the risk to the Cuvette Centrale peat, which stores about 30.6 billion tonnes of carbon [1].
• Taken together, these show that tropical forests are carbon stores of global importance, and protecting them needs cooperation between countries.

Related concepts

• Congo Basin rainforest
• Tropical grasslands of the world
• Taiga

Read more

• Natural regions I: rainforests, savannas, monsoon lands, taiga and tundra