Species diversity and distribution of herbaceous plants in the floodplain of the middle Amazon

In the Amazon floodplain near Manaus 387 species of herbaceous plants, belonging to 182 genera and 64 families were recorded. 330 species are considered terrestrial, 34 aquatic, 20 palustric and 3 of intermediate status. Most of the terrestrial species occur occasionally and in small numbers, and prefer areas on the levees, which are flooded only during periods of a few weeks or months. Only 5 species frequently formed large monospecific stands and 12 others were very frequent. It is assumed that the disturbance by the regular, monomodal floodpulse of the Amazon River creates a large number of habitats, maintains the communities at a low seral stage and avoids elimination of species by interspecific competition