The burned areas in Brazil have been the cause of much concern and controversy. The burnings affect many ecological and agricultural systems, creating negative environmental impacts on both local and regional level. Almost all the different kinds of forests that occur in the Amazon Basin and in the Atlantic Coastal areas are too humid to burn. But even there, accidental fires only occur if the vegetation is disturbed as a consequence of logging and trails formed by hunters trails. Here, branches and leaves are exposed to the sun and become dry and highly flammable after a very dry season.
Trees have to be cut down, then dried during a period of several months, to be ready for burning.
Burnings are made purposely. Wildfires can be the result of uncontrolled burnings, that reach the native vegetation, besides all other well known fire causes, e.g. cigarettes on roadside grasslands, lightnings, arson, etc. Like the African savannahs, this vegetation burns easily and periodically. But, still there, natural fires are minor. The cerrados usually are the first patches of wildland occupied by farmers and settlers, because it demands less efforts to be cultivated.