Shifting cultivation
Like other mountainous areas in South and Southeast Asia, the Chittagong Hill Tracts are undergoing deforestation and land degradation arising from environmentally unsuitable activities such as tobacco cultivation in sloping land, shifting cultivation and logging. Shifting cultivation, also known as slash-and-burn agriculture or swidden cultivation, embraces a large variety of primitive forms of agriculture. It is a special stage in the evolution from hunting and food gathering to sedentary farming. Mankind began to change its mode of life from food gatherer to food producer about 7000 B.C. by adopting shifting cultivation. Some form of shifting cultivation has been practised in most parts of the world, but more intensive forms of agriculture have subsequently replaced it.