Here is your short paragraph on the factors affecting vegetation of India:
Natural vegetation is the primeval plant cover unaffected by man either directly or indirectly.
The word forest is derived from Latin ‘fores’ meaning outside, the reference being to a village boundary or fence and it must have included all uncultivated and unhabited land.
In general, a forest is defined as an area set aside for the production of timber and other forest produce or maintained under woody vegetation for certain benefits which it provides. Ecologically, a forest is a plant community, predominantly of trees and other woody vegetation, usually with a closed canopy.
The geographical factors which influence natural vegetation include climate, soil and topography. The main climatic factors are rainfall and temperature. Generally speaking, rainfall is more important than temperature except in the Himalayas.
The seasonal rainfall regime, the length of dry season and its relation to the march of temperature, are also important. The amount of annual rainfall has a great bearing on the type of vegetation. Areas receiving 200 cm or more rainfall per annum have stands of evergreen rain forests while monsoon deciduous forests dominate in areas with rainfall between 100 and 200 cm.
In areas having 50 to 100 cm rainfall there are drier deciduous or tropical savana grading into open thorny scrub while those with less than 50 cm rainfall have only dry thorny scrub and low open bush merging into semi desert. In higher altitudes of the Himalayas and the hills of the Peninsula at elevation of more than 900 metre above sea level, temperature plays a more important role.
As the temperature falls with altitude in the Himalayan region the vegetal cover changes from tropical to subtropical, temperate and finally alpine. Changes in soil conditions have given birth to different types of vegetation in different parts of the country.
Mangrove forests, swamp forests, and beach and sandy coastal forests are some of the outstanding examples of influence of soil on natural vegetation. Topography in the narrow sense is responsible for certain minor type’s e.g. alpine flora, tidal forests, etc.