Estrutura e síndromes de dispers o de espécies arbóreas em um trecho de mata ciliar, Sirinhaém, Pernambuco, Brasil Structure and dispersal syndromes of tree species in a stretch of riparian vegetation, Sirinhaém, Pernambuco State, Brazil

Este trabalho teve por objetivo conhecer a fitossociologia do componente arboreo em uma mata ciliar de um corrego que desagua no Rio Sirinhaem, localizado no Engenho Buranhem, Sirinhaem, PE e identificar as sindromes de dispersao das especies. O corrego esta situado em um fragmento de Floresta Ombrofila Densa de Terras Baixas, com 272 ha. Utilizou-se como area amostral um hectare (40 unidades amostrais, 10 m x 25 m) onde foram registrados 1.307 individuos arboreos com circunferencia a altura do peito (CAP) ≥ 15 cm. Foram identificadas 118 especies, pertencentes a 40 familias botanicas. Protium heptaphyllum e Pouteria sp.1 foram as especies mais abundantes. Em termos de valor de importancia (VI), as especies Protium heptaphyllum, Pouteria sp.1 e Virola gardneri estao entre as mais importantes ecologicamente. As sindromes de dispersao predominantes foram: zoocoria (72,8%), autocoria (13,6%) e anemocoria (4,8%). Nao foi possivel determinar a sindrome de dispersao de 8,8% das especies estudadas. doi: 10.4336/2012.pfb.32.69.01 This study aimed to know the phytosociology of the tree component of riparian vegetation in a stream that flows into the Sirinhaem River in Engenho Buranhem, Sirinhaem, Pernambuco State, and identify the species dispersal syndromes. The stream is located in a fragment of dense rain forest of the lowlands, with 272 ha. It was sempled used one hectare (40 sampling units of 10 m x 25 m each). It was registered 1,307 trees with circumference at breast height (CAP) . 15 cm. We identified 118 species belonging to 40 botanical families. Protium heptaphyllum and Pouteria sp.1 were the most abundant species. In terms of importance value (IV), Protium heptaphyllum, Pouteria sp.1 and Virola gardneri are among the most important ecologically species. The predominant dispersal syndromes were zoocory (72.8%), autocory (13.6%) and anemochory (4.8%). It was not possible to determine the type of dispersal of 8.8% of the species studied. doi: 10.4336/2012.pfb.32.69.01