Neotropical savannas: Their flora and vegetation.

Covering approximately three million km(2), the savannas, the second largest major plant formation in the American tropics, are gaining increasing importance for land planning and occupational strategies. There has been much recent research on the floristic and ecological characteristics of these herbaceous ecosystems, resulting in considerable progress in the understanding of their complex ecological interrelationships. Hitherto little-known savanna "islands" within the Amazon region are being intensively studied, offering interesting information on their origin and dynamic relationships with the surrounding forests. Important gaps remain to be filled, however, before a critical evaluation of the great variety of neotropical savanna ecosystems is achieved and the preservation of at least some of these unique plant formations is assured.