Leave the land alone for a few years and it will reseed itself. The longer the land has been cleared, however, the more it has been cultivated, the greater the size of the clearing, the longer it will take to come back. According to the Brazilian government, the major cause of deforestation in the Amazon is the clearing of land for crops or cattle, invariably done by cutting the trees and burning them. Because logging is usually done selectively, the loggers taking only certain trees in a forest, logging is not considered deforestation, though it indirectly contributes. If loggers cut a road in the Amazon to reach a new section of forest, the landless poor often follow, clearing the rest of the land for their small farms.
Deforestation concerns people for two major reasons.
Along with the destruction of the trees, perhaps thousands of plant and animal species might become extinct, because rain forests are the most species-rich ecosystems in the world. Some conservationists argue those organisms should be preserved for no reason other than that we should not knowingly wipe out other life forms. Amazon natives use hundreds of plants to treat many common ailments, but many of those treatments remain unexplored by modern medicine. Second, there is the fear of radical climate change. Each acre of forest that burns releases more than 80 tons of carbon, primarily in the form of carbon dioxide, a gas that traps solar heat and is thought to increase global warming.