Fire in the Tropical Rain Forest of the Amazon Basin

Abstract

Fire has long played an important role in the formation of vegetation types in Amazonia. During the Pleistocene, a large part of Amazonia was covered by grassland, with forest confined to small refugia (the number, size, and evolutionary importance of which are the subject of controversy) (Prance 1982). This period coincided with the arrival of the first humans in the area. Fires started by precolumbian human groups would have slowed the progress of recolonization of the grasslands by forest (e.g., Budowski 1956). Human-initiated burning of grasslands could be expected to affect both the 165,000 km2 of humid savannas of present-day Amazonia (such as those in Roraima in the Humaitá area of the state of Amazonas) and the limit between the forest and the cerrado or central Brazilian scrubland. Charcoal in the soil of the lavrados (“natural” grasslands) of Roraima indicate large-scale burning about 1000 years B.P. (Sternberg 1968).