Tropical Evergreen (Rain) Forests in India: Where They Are Found

An evergreen forest in India grows in three places: the western slope of the Western Ghats, the hills of the north-east and the Andaman and Nicobar Islands. These are India’s tropical rainforests. They grow in warm, humid areas with a very high yearly rainfall of over 200 cm, most of it brought by the south-west monsoon.

India has several kinds of tropical forest, from evergreen and semi-evergreen to deciduous and thorn forests. The evergreen group is the first of NCERT’s five forest groups. For how they fit alongside deciduous, thorn, montane and coastal forests, see the hub guide to types of forests in India. This page stays with the wettest group only. It explains where these forests grow, what makes them special and why they matter.

Where are evergreen forests found in India?

In India, evergreen forests are found in three regions, according to NCERT’s Class 11 chapter “Natural Vegetation”. Each one gets heavy rain from the monsoon winds.

Western slope of the Western Ghats

The Western Ghats run parallel to India’s west coast. NCERT’s climate chapter explains that one branch of the Arabian Sea monsoon is blocked by these hills. The moist winds climb the slopes, cool down and drop their rain. So the windward side of the Sahyadris and the coastal plain gets about 250 to 400 cm of rain.

East of the crest, the winds sink and warm up, and rainfall drops sharply. This drier belt is a rain-shadow area. That is why evergreen forest clings to the western, sea-facing slope and does not spread across the plateau.

Hills of north-east India

The second home is the hill country of the north-east. Here the Bay of Bengal branch of the monsoon brings very heavy rain. NCERT notes that annual rainfall exceeds 400 cm in Meghalaya. Its textbook also says Mawsynram, on the crest of the Khasi Hills, receives the highest average annual rainfall in the world.

Andaman and Nicobar Islands

The third home is the island chain in the Bay of Bengal. NCERT states plainly that the Andaman and Nicobar Islands have tropical rainforests. ISFR 2023 likewise names these islands, the Western Ghats and the north-eastern states as the places where India’s tropical evergreen forests occur.

What climate do tropical evergreen forests need?

NCERT describes the evergreen belt as warm and humid. Two numbers define it:

• Rainfall: an annual precipitation of over 200 cm.
• Temperature: a mean annual temperature above 22 °C.

That total is not shared out evenly across the seasons. NCERT’s climate chapter says the windward side of the Western Ghats and Assam receive high rainfall during June-September, the south-west monsoon season. A large yearly total, humid air and steady warmth are what keep these forests evergreen, not rain in every month. Where rain is a little lower, the evergreen forest gives way to semi-evergreen forest, and then to moist deciduous forest. Our page on the difference between tropical evergreen and deciduous forests compares these two forest families side by side.

Is India a tropical country?

Only part of India lies in the tropics. NCERT’s chapter on climate says the Tropic of Cancer passes east to west through the central part of the country. The land south of this line falls in the tropical zone and stays hot through the year. The northern part lies in the sub-tropical and temperate zone, with a much wider range of temperature.

NCERT also describes India’s climate as a hot monsoon climate, shared with south and south-east Asia. So the safest exam answer is this: India has a tropical monsoon climate in most areas, but it is not wholly tropical. All its tropical evergreen forests grow in the warm, wet regions described above.

What are the features of tropical evergreen forests?

NCERT lists several features that set these forests apart:

1. Many layers (stratification). Shrubs and creepers cover the forest floor. Short trees form the next layer, and tall trees tower over them.
2. Very tall trees. Some trees reach 60 m or even more.
3. Green all year. Trees have no fixed time to shed leaves, flower or fruit. Each species keeps its own calendar, so the forest never looks bare.
4. Dense growth. The layers crowd together, so little sunlight reaches the ground.

Stratification simply means arrangement in layers, like floors in a building. Each floor has its own light, moisture and animals.

Which trees grow in tropical evergreen forests?

NCERT names rosewood, mahogany, aini and ebony as typical tropical evergreen forest trees in India. Many of them yield hard, valuable timber. That value has made them targets for felling in the past.

Semi-evergreen forests grow in the less rainy parts of the same three regions. The table below shows how the two kinds differ, using NCERT’s description.

NCERT lists kail among the semi-evergreen species. In most Indian usage, though, “kail” means blue pine, a Himalayan conifer. ISFR 2023 records “Blue pine (Kail)” forests in Himalayan states such as Jammu and Kashmir and Himachal Pradesh. NCERT places blue pine at 2,225-3,048 m in the Himalayas. Read more in our guide to coniferous forest in India.

Is there a tropical rainforest in India?

Yes. A tropical rainforest is a dense evergreen forest in a hot, wet climate. NCERT uses this very term for the forests of the Western Ghats and the Andaman and Nicobar Islands. So “rainforest in India” and “tropical evergreen forest in India” describe the same wet forests.

India’s rainforests lie farther from the Equator than the great rainforests of the Amazon or Congo. They depend on the summer monsoon, not on rain in every month. Even so, they share the rainforest’s layered structure and huge variety of life. National Geographic sums up why these forests matter worldwide. Tropical rainforests contain more than half of the world’s biodiversity. For the global picture, read our guide to the tropical rainforest biome.

Silent Valley: a rainforest case study

Kerala’s Silent Valley National Park is a well-known Indian rainforest. A 2009 PIB feature describes it as one of the last undisturbed tracts of tropical moist evergreen forest in India. Its core of about 89.52 km² lies in the Nilgiri Hills, in Palakkad district.

The same feature gives a mean annual rainfall of over 5,000 mm in the park’s western Neelikkal area. The eastern side gets around 3,200 mm. According to a 2009 PIB feature, Silent Valley holds the largest population of the lion-tailed macaque. Nilgiri langurs, Malabar giant squirrels and great Indian hornbills also live there. See our guide to animals of the tropical evergreen forest for more examples.

How much area do evergreen forests cover in India?

The Forest Survey of India (FSI) maps forests using Champion and Seth’s 16 forest type groups. Two of them match NCERT’s evergreen and semi-evergreen forests. ISFR 2023 Table 5.2 gives their areas:

Together the two groups cover 87,774 km². That is far smaller than the tropical dry deciduous group, India’s largest at 2,80,580 km². Growing stock is the volume of wood standing in a forest. Wet evergreen forest packs much more wood into each hectare than semi-evergreen forest.

ISFR 2023 also lists a separate Tropical Dry Evergreen group of just 801 km². Do not confuse it with the rainforests on this page; its name refers to leaf habit, not to heavy rain.

Why are India’s evergreen forests important?

These forests are among India’s richest stores of life. The Convention on Biological Diversity’s India profile counts the country in four biodiversity hotspots: the Himalaya, Indo-Burma, the Western Ghats and Sri Lanka, and Sundaland. A biodiversity hotspot is a region very rich in species that is also under threat.

The same CBD profile reports more than 50% species endemism among reptiles, amphibians and fish in the Western Ghats. Endemic species live naturally in one region and nowhere else. Our page on biodiversity hotspots in India explains all four in detail.

Evergreen forests also resist fire better than drier forests. ISFR 2023, citing an FSI study from 2015, notes that evergreen and semi-evergreen forests are relatively less susceptible to fire. Dry deciduous forests are far more fire-prone.

Beyond wildlife, these forests protect steep slopes from soil erosion. They feed rivers that flow down from the Western Ghats and the north-eastern hills. They also give timber, medicines and food to forest communities.

What threatens evergreen forests and how are they protected?

NCERT records that the British cleared Indian forests to plant tea, rubber and coffee. The PIB feature on Silent Valley adds present-day threats in Kerala. It names forest fires caused by negligence or lit by herders seeking fresh grass. It also mentions the felling of evergreen forest in the nearby Attappady Hills.

Protection now comes through national parks and biosphere reserves. A biosphere reserve is a large protected landscape where conservation and local livelihoods are planned together. NCERT’s table lists the Nilgiri Biosphere Reserve (1986), spread over Tamil Nadu, Kerala and Karnataka. It also lists the Great Nicobar Biosphere Reserve (1989) in the Andaman and Nicobar Islands. Silent Valley forms a core area of the Nilgiri reserve.

The same wet tropical belt also holds other forest types. Mangroves line the island coasts, as our page on littoral and swamp forests in India shows. Higher up the southern hills, rainforest gives way to the Sholas described in our guide to montane forests of India. At the opposite extreme, the dry west carries tropical thorn forests and scrubs.

Sources

• NCERT Class 11, India: Physical Environment, Chapter 5 “Natural Vegetation”
• NCERT Class 11, India: Physical Environment, Chapter 4 “Climate”
• Forest Survey of India, India State of Forest Report 2023, Volume I
• Convention on Biological Diversity — India country profile
• National Geographic Education — Vegetation Region
• PIB feature — The Silent Valley National Park (2009)