A central Amazonian terra firme forest. I. High tree species richness on poor soils

Tree size, density, and species richness were established for three one-hec tare plots of terra firme forest in central Amazonian Brazil. In the three hectares, 1916 individual trees with DBH greater than or equal to 10 cm wer e sampled. A total of 58 families, 181 genera, and 513 species were determi ned. Hectare A had 285 species, 138 genera, and 47 families; hectare B 280 species, 123 genera, and 48 families; and hectare C 280 species, 125 genera , and 44 families. Comparably high species richness in Amazonia has heretof ore only been reported from western Amazonia. This dispels the idea that hi gh species richness can only develop in areas with rich soils and relativel y high rainfall. It is suggested that such high species richness is the res ult of a combination of habitat heterogeneity and geological history. These high diversity forests, because they occur on nutrient poor soils, can be protected with little or no impact on development in the region because the soils are essentially useless for agriculture and for supporting long-term cattle pasture.