ABSTRACT
Seasonally dry tropical forests (SDTF) of Ecuador have been variously referred to as bosque seco, bosque espinoso, matorral seco, deciduous or semideciduous forest, and dry cactus scrub, amongst others. Isolated areas of this vegetation type occur in the dry inter-Andean valleys of southern Ecuador and in coastal Ecuador to the west of the Andes. Together with similar SDTF pockets in northern Peru they form part of the Tumbesian Centre of Endemism, a region of fragmented diverse forest types. Recent studies by Pennington et al. (2000, 2004) have shown that SDTF are scattered throughout the Neotropics, and these have been interpreted as isolated fragments of earlier more widespread vegetation. The floristic component of these seasonally dry forests is quite distinct from the savannas, cerrado, chaco and llanos vegetation types of South America. The woody Leguminosae of southern Ecuador have been studied in detail (Lewis and Klitgaard, 2002) permitting a comparison of the local SDTF legume flora with other neotropical seasonally dry forests. While a small number of woody legumes are narrowly restricted endemics in southern Ecuadorean SDTF, many more are found also in similar SDTF in northern Peru. Still others are to be found either widely dispersed amongst, or disjunct between, pockets of this vegetation type throughout the Neotropics. Examples of these different distribution patterns are presented and discussed, and the neotropical SDTF are considered in the context of a recently defined global legume ‘succulent biome’.
