Foram estudados os aspectos da fenologia reprodutiva das espécies freijo-cinza (Cordia goeldiana Huber), carapanaúba, (Aspidosperma oblongum A.DC..), sucupira-preta (Diplotropis purpúrea (Rich) Amusch.); sumaúma (Ceiba pentandra (L.) Gaertn.) e quaruba -verdadeira (Vochysia máxima Ducke). Os objetivos foram: quantificar a dispersão de sementes, avaliar as fenofases reprodutivas e determinar a distribuição espacial dessas espécies. Foi demarcada uma área de 400 Ha na floresta nacional do Tapajós, em Santarém, Pará. Detectou-se uma relação direta entre tamanho de sementes e a sazonalidade da dispersão. Sementes sem aparato de vôo mostraram dispersão mais abundante (89,3%) do que aquelas com aparato de vôo (10,7%) Freijo-cinza e sumaúma disseminaram no final do período menos chuvoso, enquanto que a carapanaúba, a sucupira-preta e a quaruba- verdadeira disseminaram suas sementes no período de maior queda pluviométrica. As espécies deste estudo apresentaram distribuição espacial aleatória ou dispersa

Aspects of reproduction phenology and seed dispersaI for freijó-cinza (Cordia goeldiana Huber); carapanaúba (Aspidosperma oblongum A.DC.); sucupira-preta (Diplotropis purpurea ( Rich.) Amusch.); sumaúma (Ceiba pentandra (L.) Gaertn.) and quaruba-verdadeira (Vochysia maxima Ducke), were studied. The main objectives were: a) to quantify the dispersaI of seeds, classifying the species according to seed flight apparatus; b) to evaluate the reproductive phenology phases; and c) to determine spatial distribution patterns of the studied species. Phenology and spatial distribution of the individual trees were studied by demarcating a 400 ha area which was divided in a hundred 4 ha plots (200 m x 200 m). A 100% inventory of the individuaIs over 30 cm diameter was carried out. Maps were drawn locating alI the trees belonging to the five studied species. In the central part of the 400 ha area, nine 4 ha plots were selected where collection traps were installed for seed dispersal study of alI the species present in the area. A wide temporal amplitude was observed for seed dispersal in the studied forest. It was detected that seeds with flight apparatus present specific aerodynamic properties. A direct relationship between seed size and dispersal seasonality was observed. Seeds without flight apparatus present a more abundant dispersal (89.3%) than seeds with flight apparatus (10.7%). Dispersal of seeds with flight apparatus is mainly concentrated in the dry season. "Freijó-cinza" and "sumaúma" disseminated their propagules in between the end of the dry season and the beginning of the rainy season whereas "carapanaúba", "sucupira-preta" and "quaruba-verdadeira" disseminated their seeds during the period of highest rainfall. It was observed that in the whole studied area "freijó-cinza", "sumaúma", "carapanaúba" "sucupira-preta" and "quaruba-verdadeira" present random spatial distribution with variation according to the methodology used