Tropical rain forests include typical rain forests. They are further sub- classified into wet tropical evergreen and moist tropical semi-evergreen forests. The distribution and characteristics of these sub-classes are as under:
Wet Tropical Evergreen Forests:
They are found in the regions of very high annual rainfall, exceeding over 300 cms. Shillong Plateau, Southern Sahyadris of Kerala and Karanataka are known for these forests. They resemble the Equatorial type of vegetation.
Major characteristics of these forests are as under:
1. These forests are very dense and lofty.
2. There are numerous species of trees in these forests.
3. They are important for spice gardens.
4. Major trees include Mahogany, Cinchona, Bamboos and Palms.
5. Undergrowth of creepers is dense and thick. Grass is almost absent in these forests.
Moist Tropical Semi-Evergreen
These forests are bordered by semi-evergreen forests. Annual rainfall varies between 200 to 300 cms. The areas of Shillong plateau in the northeast, the Sahyadris in the south-west and the Andaman and Nicobar Islands in the south-east have these forests. Major characteristics of these forests include:
1. These forests are less dense than the wet evergreen forests.
2. Shifting cultivation and colonial exploitation for timber have depleted the vegetation to a great extent.
3. They are known for fine grained and good quality timber.