Natural grasslands occur in temperate zone with annual rainfall between 28-30 c.m., while in tropics they may be formed in areas receiving rainfall up to 150cm.
Misra (1983) has regarded all tropical grasslands of India as ‘Savannahs’. It is a kind of grassland dominated by grass with scattered trees or shrubs. The grasslands of India are divided in to eight major types by White (1957). These are as follows—
1. Sehimia-Dichanthium type: The dominant grasses are Sehimia, Dichanthium, Chrysopogon and Themeda. These grasslands are wide spread in the black soils of Maharashtra, M.P., South-western parts of U.P. and parts of Tamilnadu and Karnataka.
2. Dichanthium-Centhrus type: The most extensively distributed type of grassland on the sandy loam soils of the plains of the Punjab, Eastern M.P., Coastal Maharashtra and Tamilnadu. The dominant species are Dichanthium annulatum and Cenchrus ciliaris, which are most important fodder grasses.
3. Phragmitis-Saccharum type: Located in mashy (bran, meal, or malt mixed with warm water and used as food for horses, cattle, or poultry) localities of the Terai areas of northern U.P., Bihar, Bengal, Assam and Tamilnadu. The dominant species are Phragmitis karka, Saccharum spontaneum, Imperata cylindrical etc.
4. Bothriochloa type: Found on high rainfall paddy fields of Lonavala tract of Maharashtra. The dominant species is Bothriochloa odorata.
5. Cymbopogon type: Restricted to the low hills of the Western Ghats, Vindhyas, Satpura, Aravali and Chota Nagpur. The dominant grass is Cymbopogon, others are Themeda, Heteropogon and Aristida.
6. Arundinella type: It is found in high hills of the Western Ghats, Nilgiris and throughout the lower regions of Himalayas. The dominant species are Arundinella sps. followed by Themeda anathera and Chrysopogon sps.
7. Deyeuxia-Arundinella type: It is found in temperate regions of the Upper Himalayas between 2000m to 3000m from Assam to Punjab and Himachal Pradesh. The dominant grasses are Deyeuxia, Arundinella, Brachypodium, Bromus and Festuca.
8. Deschampsia-Deyeuxia type: These grasslands are restricted to the alpine regions of Himalayas (above 3000m). the climate is very cold and soils are thin. Deschampsia, Deyeuxia, Poa, Stipa, Glyceria and Festuca are more common genera.