Published on 07/05/2011
First Update 17/03/2017
Of all the species known to mankind, more than 40 to 50 % are harbored in areas covered by just about 7 % of the world’s area – the tropical rainforests – a region also of heavy rainfall. Tropical rain forests are spread through north eastern India ( Khasi Janitia hills and the lower Himalayan slopes embracing areas of Arunachal Pradesh, Assam, Meghalaya, Nagaland and Tripura) and the Western Ghats region in the South including the Malabar coast. Many of the plant and animal species are common to both the areas. Rain forests consist of very dense and lofty trees with a multitude of species appearing in the same area.
Hundreds of species of trees can be identified in a hectare of land apart from a rich diversity of mosses, ferns, epiphytes, orchids, lianas, vines, herbs and shrubs and fungi etc.
Altogether they make this area the most diverse habitat. Giant trees spread up towards the sun. Buttress roots support the smooth straight trunks, which rise 30 meters or so before branching out. The spreading crowns effectively block off most of the light from the ground beneath.
Dipterocarpus spp predominate in this area. Other small plants gain access to the life giving sunlight by climbing to the branches of the giant trees. Many of these epiphytes have roots and tubers adapted for collecting and storing moisture from their host when there is rain. The emergent trees constitute the top canopy which absorbs most of the sunlight. This is followed by the middle storey of shade tolerant species and the young siblings of the taller dominants. The lowest storey is almost bare with only a few seedlings of palms, cardamom and ginger. The ground is strewn with a carpet of fallen leaves and decaying wood with occassional tangles of cane. It is in this environment that live a host of animals of all kinds. On the ground only big herbivores like elephants, the Tahr ,the barking deer can survive. Most of the species are tree dwellers. Over millions of years animals have evolved in the tropical rain forests as specialised climbers and fliers, spending all their lives in the canopy and specialist feeders always eating fruits from a limited range of plant species. Amongst the tree dwellers the most prominent are the primates, the gibbon, langurs, monkeys and the macaques. The south is inhabited by the Lion Tailed Macaque that is now regarded as endangered, the Nilgiri langur and the Slender Loris are other primates of this region.
A host of bats, flying mammals inhabit the region apart from giant squirrels, civets and the striped neck mongoose. A number of climbing animals have evolved gliding mechanisms which are very characteristic of the tropical rain forests. The flying squirrel is one of them.
The flora and fauna of these evergreen regions have not been fully explored. Being a storehouse of a large variety of plants and animals, these forests represent one of the richest genepool resources of flora and fauna in the country.