AMAZONIA
Location
Terra Preta soils are found mainly in Amazonia, where Sombroek et al estimate that they cover at
least 0.1 to 0.3%, or 6,300 to 18,900 km² of low forested Amazonia (cited by Denevan and Woods);
but others estimate this surface at 1.0% or more (twice the surface of Great-Britain).
Plots of Terra preta exist in small surfaces averaging 20 hectares, but near-900 acres' surfaces have also
been reported.
They are found among various climatic, geological and topographical situations.
Their distribution either follows main water courses, from East Amazonia to the central basin of Ama-
zonia[9], or are located on interfluvial sites (mainly of circular or lenticular shape and of a smaller size averag-
ing some 1.4 ha), see also distribution map of Terra Preta sites in Amazon basin.
Williams W. Woods (soil biologist at Southern Illinois University) estimates that around 10% of the original terra comum appears to have been converted to Terra preta. According to William Balée (anthropologist at Tulane University in New Orleans), the spreads of tropical forest between the savannas could be mainly anthropogenic –
a notion with dramatic implications world-wide for agri-
culture and conservation.
Terra preta sites are also known in other South American areas (Ecuador, Peru, Guyana)[13], in West Africa
(Benin, Liberia), and on the South African savannas.
Similar soil was found in late Roman Britain - see dark earth.
