On the vegetation of a seasonal mixedwater inundation forest near Manaus, Brazilian Amazonia

The species composition of an area of 0.5 hectare of seasonal inundation forest located between the blackwater Negro River and the whitewater Solimoes River at Lago Janauari near Manaus. Brazil, was studied. Sixty-six arboreal species representing 55 genera and 31 families were recorded. Total basal area was 15 m(2) and bole volume was 125 m(3). The most abundant species were Pouteria sp. (Sapotaceae) and Pterocarpus amazonum (Fabaceae). The highest basal area per species: was 2.15 m(2) for Calophyllum brasiliense (Clusiaceae). The vegetation in the study area represented an ecotone with characteristic tree species of the seasonal inundated forests in the whitewater (varzea) or/and blackwater (igapo) region of Central Amazonia. Following the terminology of Amazonian forest types subject to inundation (PRANCE 1979) it is therefore named "seasonal varzea & igapo" or "mixedwater" inundation forest.