Before we start with the top 5 Tropical Forests in India, let us understand the basics.
Tropical Forests Definition:
According to the Glossary in Environmental Statistics, Studies in Methods, Series F, No. 67, United Nations, New York, 1997, “Tropical forest is a type of forest found in the areas with high regular rainfall and no more than two months of low rainfall, and consisting of a completely closed canopy of trees that prevents penetration of sunlight to the ground and discourages ground-cover growth.”
In simple terms, the tropical forests inhabit the areas which receive normal to heavy rainfall almost all round the year. There are many trees in the tropical forests due to which sunlight doesn’t penetrate to the ground and there is very little growth of any smaller species of flora on the ground.
- Temperature: 25-30 degrees Celsius
- Rainfall: Usually more than 200 cm
- Location: Closer to the equator.
Now that we have understood the meaning of tropical forests, let us dive into our topic Top 5 Tropical Forests in India.
1. Tropical Forests in India: Andaman Islands Tropical Rainforests
According to the State of Forest report (2003), published by Forest Survey of India, 84.4% of the Andaman Islands is covered with forests. There are 12 different varieties of forests in the Andaman Islands. Some of them are littoral forests, Andaman tropical evergreen forests, the Andaman semi-evergreen forests, Andaman moist deciduous forests, the Southern Hilltop evergreen forests, the Andaman secondary moist deciduous forests etc. Because of the wide forest cover and given the fact that they are tropical forests, there is rich diversity in both flora and fauna. The forests of the Andaman is home for 200 species of timber out of which 30 are commercial.
Fauna present in these forests are influenced by fauna of Indo-Chinese and Indo-Malayan regions. Big mammals are not seen and endemic species (the species which are seen only in one region and not anywhere else) are high in number due to geographical isolation.
- No. of species – 62 (32 of them are endemic)
- Important species – Dugong (Dugong dugon), Dolphin (Delphinus delphis), Spotted deer (Axis axis)
- No. of species – 246 (99 of them are endemic)
- Important species – Andaman Teal (Anas gibberifrons albogularis), Megapode (Megapodius nicobaresis)
- No. of species – 76 (24 out of 76 are endemic)
- Important species – Leatherback turtle (Dermochelys coriacea), Water Monitor Lizard (Varanus Salvator), Reticulate Python (Python reticulatus)
Acquatic life forms
- No. of species – 2729
- Important species – Boomerang coral (Herpolitha limax), Boulder coral (Porites porites)
Apart from the endemic species, exotic species (the species which are not found in that particular geographical location but are introduced) are also present. Spotted deer, house sparrow, giant snail etc. are few of the exotic species of tropical forests of the Andaman Islands. Though it is said that there is some ecological imbalance because of the exotic species, no study has been conducted so far to prove this.
To protect the wildlife of the these forests, 96 wildlife sanctuaries, 9 national parks and one biosphere reserve have been started by the Union Territory’s government.
2. Tropical Forests in India: Brahmaputra Valley Semi-Evergreen Forests
These forests are seen primarily in the state of Assam and parts of West Bengal, Arunachal Pradesh and Nagaland. Because of the presence of alluvial soil, these forests are considered as one of the most productive regions in India. The wildlife of Brahmaputra Valley is influenced by the flora and fauna of Indo-Malayan region. Some forms of wildlife are limited to one of the banks of mighty Brahmaputra River. For example: golden langur (Semnopithecus geei), hispid hare (Caprolagus hispidus) are present in the north bank whereas hoolock gibbon (Hylobates hoolock) and stump-tailed macaque (Macaca arctoides) are found only in the southern banks. As this area is populated, the forests regions are being converted into grasslands and agriculture lands by people.
- Important species – Syzygium, Cinnamomum, Artocarpus
- No. of species – 122 (2 of them are near endemic)
- Important species – Elephants, one-horned rhinoceros, tigers, wild water buffalo
- No. of species – 370 (2 of them are near endemic)
- Important species – Bengal florican, Manipur bush quail.
This valley is home for Asiatic elephants and has the greatest number of one-horned rhinoceros in the world.
National Park/ Wildlife Sanctuary: Manas National Park
3. Tropical Forests in India: North Western Ghats Moist Deciduous Forests
These forests surround the montane rainforests and the population of both large prey and predators is high in these forests. They are present in states of Maharashtra and Karnataka. Like the above two forests, the flora and fauna of these forests are influenced by the ones in Indo-Malayan origin. These forests have Gondwana origins i.e., the Deccan plate detached itself from the Gondwana island and got attached to Eurasia during the Cretaceous period. Compared to the South-Western Ghats moist deciduous forests, North Western Ghats moist deciduous forests are not studied properly.
- Important species – Butea superba, Kydia calycina
- No. of species – 87
- Important species – Tiger (Panthera tigris), Elephant (Elephas maximus), Gaur (Bos gaurus)
- No. of species – 345 (5 of them are near-endemic)
- Important species – Nilgiri wood pigeon (Columba elphinstoni), Malabar parakeet (Psittacula columboides)
Nearly 3/4th of these forests are converted into grasslands and agriculture lands.
National Park/ Wildlife Sanctuary: Anshi National Park, Bhadra Wildlife Sanctuary etc.
4. Tropical Forests in India: Odisha Semi-Evergreen Forests
These forests are neither high on endemism nor a species-rich ecoregion. Yet these forests are home for large vertebrates like Tiger (Panthera tigris), Elephant (Elephas maximus), Gaur (Bos gaurus). It also has origins from Gondwana land and therefore, there exists an ancient biota in these forests. The flora has three layers. The upper story has species like Artocarpus lakoocha, Michelia champaca, Celtis tetrandra, Bridelia tomentosa, B. verrucosa etc. The second story has species like Aphanamixis polystachya, Mesua ferrea, Phoebe lanceolata, Polyalthia spp., Macaranga peltata, Glochidion spp., and Litsea nitida and the third and bottommost story is covered by evergreen shrubs, canes, and herbs.
- Important species – Artocarpus lakoocha, B. verrucosa
- No. of species – 59
- Important species – Tiger (Panthera tigris), Elephant (Elephas maximus), Gaur (Bos gaurus), wild dog (Cuon alpinus), sloth bear, and chousingha (Tetracerus quadricornis)
- No. of species – 215
- Important species – the lesser florican (Eupodotis indica), Oriental darter (Anhinga melanogaster)
95% of these forests are cleared by human habitation and used for agricultural lands.
National Park/ Wildlife Sanctuary: Chilka Wildlife Sanctuary, Balukhand-Konark Wildlife Sanctuary.
5. Tropical Forests in India: South Western Ghats Moist Deciduous Forests
These forests are the most endemic and species-rich ecoregion in Deccan peninsula. Large animals like Tiger (Panthera tigris), Elephant (Elephas maximus), Gaur (Bos gaurus) inhabit these lands. Grasslands and patches of Shola forests are characteristic of these deciduous forests. Once in 12 years, the flower called Neelakurunji (Phlebophyllum kunthianum) colours the mountains in blue and it is a treat to our eyes.
These forests are present in the southern part of the Western Ghats and are in the states of Tamil Nadu and Kerala. Just like the above 4 tropical forests even this one was a part of Gondwana land. The rainfall is anywhere between 250-800 cm during different seasons. Because of this, there is variation in habitats and high endemism is seen. The flora of these forests includes Mesua ferrea, Palaquium ellipticum, Gluta travancorica, and Podocarpus wallichiana, Calophyllum austroindicum, Garcinia rubro-echinata, Garcinia travancorica, Diospyros barberi, Memecylon subramanii.
- Important species – Mesua ferrea, Palaquium ellipticum, Memecylon subramanii
- No. of species – 79 (10 of 79. Out of 10, 3 are endemic and 7 are near-endemic)
- Important species – Hemitragus hylocrius, Mus famulus, Vandeleuria nilagirica (3 endemic species) Nilgiri tahr (Hemitragus hylocrius)
- No. of species – 309 (10 of 309. Out of 10, 3 are endemic and 7 are near-endemic)
- Important species – Broad-tailed grassbird (Schoenicola platyura) Nilgiri laughingthrush (Garrulax cachinnans) Nilgiri pipit (Anthus nilghiriensis)
- No. of species – 484 (90 of 484 are endemic)
- Important species – Brachyophidium, Dravidogecko, , Ristella, Teretrurus, and Xylophis are the 5 endemic genera of 8.
- No. of species – 206 (103 of 206 are endemic)
- Important species – Indotyphlus, Nyctibatrachus, Ranixalus, and Uraeotyphlus are the 4 endemic genera of 6.
It is the home for India’s largest Asian elephant population. Though it is highly species-rich ecoregion, the diversity is not spread uniformly. For example: Agasthyamalai and Nilgiri hills are more famous for flora diversity than fauna.
According to the present estimates nearly 2/3rd of these magnificent forests have been cleared. Even the wildlife sanctuaries encourage large commercial plantations in the sanctuary itself.
National Park/ Wildlife Sanctuary: Mukurty National Park in Tamil Nadu