6 Vegetation Physiognomies

about 2 million km2, an area approximately the same as that of Western Europe, representing ca. 22 % of the land surface of Brazil, plus small areas in eastern Bolivia and northwestern Paraguay (fig. 6.1). It extends from the southern borders of the Amazonian forest to outlying areas in the southern states of São Paulo and Paraná, occupying more than 2 ° of latitude and an altitudinal range from near sea-level to 1,800 m. The dis-tribution of the Cerrado Biome is highly coincident with the plateaux of central Brazil, which divide three of the largest South American water basins: those of the Amazon, Plate/Paraguay, and São Francisco rivers. The cerrados form part of the so-called diagonal of open formations (Vanzolini 1963) or corridor of “xeric vegetation’ ’ (Bucher 1982), which includes the much drier Caatinga in northeastern Brazil and the Chaco in Paraguay-Bolivia-Argentina. This corridor runs between the two main areas of moist forest of tropical South America: the Amazonian forest in the northwest, and the Atlantic forest in the east and southeast. The Cerrado Biome was named after the vernacular term for its pre-dominant vegetation type, a fairly dense woody savanna of shrubs and small trees. The term cerrado (Portuguese for “half-closed,’ ’ “closed,’ ’ or “dense’’) was probably applied to this vegetation originally because of the difficulty of traversing it on horseback. The typical vegetation landscape of the Cerrado Biome consists of savanna of very variable structure, termed cerrado sensu lato, on th