A - THE GEOGRAPHICAL BOUNDARIES OF OUR RESEARCH
The area covered by this study includes all the tropical
lowlands of South America, thus spreading over the whole of the Amazon and
Orinoco basins and the Atlantic drainage area on the coast of Guyana, French
Guiana and Suriname (see map 1). In the south and the west, the boundaries of
this area extend slightly beyond the Amazon's southern drainage area and
overlap with the limits adopted by Brazilian geographers for `Amazonia Legal'.
The decision to follow the administrative boundaries is justified by the fact
that it coincides with the cultural borders of Amazonian Indian populations.
Other tropical rain forest areas on the South American continent have not been
taken into account because, apart from in the Choco/Darien and Sierra Perija
areas (Columbia and Panama), there is no longer much overlap between tropical
rain forest and the survival of indigenous populations. We will henceforth use
the term Greater Amazonia to refer to the area covered by this report.
Lowland rain forest extensively covers most of the area we will be
looking at. There are also two other major types of vegetation in the area,
though in lower proportions : on the one hand there is the vegetation cover on
the periphery of the Amazon basin, including such vast areas as the Brazilian
cerrado, or the llanos in Columbia and Venezuela ; on the other
hand, there is the vegetation actually included in rain forest areas : flooded
forests, montane forests and edaphic forests.