Development pressures are triggering rapid ecological, cultural, and economic changes in Amazonia, one of the world´s largest remaining forest frontiers. Some of the environmental effects of development schemes and spontaneous settlement have local and potentially regional and global repercussions. Ecological issues surrounding human activities in Amazonia include pollution from mining activities; deforestation and climate change; accelerated erosion and declining soil fertility; soil erosion and flooding; and the impact of hydroelectric dams on fisheries. It is important to develop sustainable agricultural systems to relieve pressure on the remaining forest.