Swamp forests occur in permanently flooded small forest fragments in southeastern Brazil. We studied the floristic composition and community structure (plants with DBH>5cm) of a swamp forest in Brotas municipality (48º06'W 22º16'S, 470m high), São Paulo State, Brazil. A total of 735 individuals, 32 families, and 51 woody species were recorded in the area. The most important species were Calophyllum brasiliense Camb., Protium almecega L. Marchand, Podocarpus sellowii Klotzch., Tapirira guianensis Aubl. and Dendropanax cuneatum DC. Decne. & Planch. The Shannon diversity index (2,81) was greater than that of similar forests. With respect to soil humidity, the majority of species (62%) are either generalists or prefer dry soils. However, dominant species (66% of total dominance) and species in high densities (67% of total density) prefer waterlogged soils. Differences in soil topography and the strong influence of surrounding savanna guaranteed the occurrence of species with different soil humidity requirement and determined the floristics and structure of the swamp forest.
swamp forest; flooding; riparian forest; gallery forests; phytosociology
