The extensive cutting down of forests for the purpose of extracting timber or fuel wood or to clear the land for mining, agriculture, or infrastructure. Forests are often situated in upland areas and are important in trapping rainwater. Deforestation in these areas, particularly in India and Bangladesh, has resulted in the flooding of low-lying plains; it has also led to an increase in soil erosion and hence desert formation (see desertification), resulting in crop loss and economic problems for local communities. The felling and burning of trees releases large amounts of carbon dioxide, thereby increasing global carbon dioxide levels and contributing to the greenhouse effect and climate change. Rainforests, particularly those of South America, are rich in both fauna and flora; their removal leads to an overall decrease in biodiversity and the loss of plant species that have potentially beneficial pharmaceutical effects. Despite moves to reduce deforestation, economic pressures ensure that the process continues.