An Estimate of the Number of Species of Trees in an Amazonian Forest Community

Abstract

As many as 1482 trees 10 cm. or more in diam., belonging to 179 spp., have been counted on a 3.5-hectare plot in a virgin terra firme forest near Castanhal, Para, Brazil. Evidence is given that the distr. of at least the common spp. over the territory of the plot is uniform, and the inference is drawn that about 70 spp. which may occur in the association sampled have not been encountered on the plot. Comparison of the spp. composition of the sample descr. in the present paper with that on a plot some 120 km. away studied by Black, Dobzhansky, and Pavan (1950) shows very considerable differences. The number of spp. in the different facies of the terra firme association in Amazonia may be much larger than found in the samples studied so far.