||Abstract: "The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, [investigators] provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees." P.1243092-1 right column 4th paragraph: "Second, the RAD [rank-abundance distribution] suggests that just 227 (1.4%) of the estimated 16,000 species account for half of all individual trees in Amazonia. [Investigators] refer to these species, all of which have estimated populations of >3.7×10^8 trees, as hyperdominant species (see a list of the 20 most abundant species in Table 1 (BNID 112913) and a full list in appendix S1). These hyperdominant species form the basis of the tree communities in individual plots as well, accounting for a median of 41% of trees (range = 0 to 94%, fig. S9) and 32% of species (range = 0 to 78%) per plot (fig. S9)."