Abstract
Plantations cover an unusually large per cent of the geographical area of Kerala. Their impact on the hydrological cycle, soil, atmospheric processes and climate, biodiversity and ecosystem function are discussed by taking examples from tropics and available research from Kerala. It is shown that plantations have both negative and positive impacts on environment. Adverse impacts can be reduced by taking suitable ameliorative measures. Towards this end, more research is needed in some critical areas which are identified